On Auto Dealership Service Departments

[GodFearinGunTotin]

OkieGirl has no interest in FL. but she does hate the cold..

Owen - KEEP LOOKING!! The bulletin you pointed out does not apply because the Suburban is a daily driver, it cycles the fuel tank once a week.

What model year is your suburban? Are you getting any check engine lights or codes set?

 

[indyjohn]

GFGT: OK!

2741490 looks like the one he found and performed. BUT I'm going to show him 2397771, that is a good lead! Thank you!

 

[indyjohn]

What model year is your suburban? Are you getting any check engine lights or codes set?

You are correct, it is a 2010. It has thrown the following: U0073, P0700, P069E, U0100. Essentially, when this happens, it loses its mind.

 

[indyjohn]

Sorry, I read 2397771 closer. This truck does not have heated seats.

 

[GodFearinGunTotin]

You are correct, it is a 2010. It has thrown the following: U0073, P0700, P069E, U0100. Essentially, when this happens, it loses its mind.

It's my bed time. I'm going to forward myself this info to my work computer and look for these codes and a no crank/no start comment tomorrow. I'll let you know what i find.

That first find though sounds almost exactly what you're getting though. Is it possible whatever gas station you're getting your gas from got a slug of wrong formulation of gas? It's a stretch but have you tried a different brand? (I really doubt thats it but that failure mode sounds like a dead ringer for what you described).

 

[RustyHornet]

Athough I do not work on the commercial side, I do work at a dealer. I would tell you to avoid at all costs. Finding a good technician at a dealership is really hard. Finding one that cares is nearly impossible. Almost none of them that I have talked to actually understand how the components on the vehicle work. They look at a computer and it tells them which parts to change. The guys at the independent shops usually have a better understanding and are willing to go the extra mile where the dealer tech may just give up since it wasn't in the computer. As stated already, the dealer will have access to certain things the independent guys won't. Hope you get this resolved!

 

[awames76]

hope this is ok to post. im a member over at SilveradoSierra.com ? Chevy Truck Forum | Silverado Sierra GMC Truck Forums there are a lot of techs and very knowledgeable people

 

[GodFearinGunTotin]

Doesn't have your DTCs but it's a no crank/no start...

A customer may comment that they may have an intermittent no crank, no start, or start stall concern with the security light coming on. Upon diagnosis the dealer technician may find DTC's B3055, B3060, and/or B3935. In most cases, the dealer cannot duplicate the customer's concern.

It is also possible on vehicles equipped with passive entry/start (RPO's ATH and/or BTH) a customer may exhibit a concern with passive entry inoperative and/or no fob detected message, but will start with the fob in the fob pocket.

With the advancements in today's technology there has been a great increase in the number of RFID (Radio Frequency Identification Devices) found across many communities, business, and automobiles. The most common devices found are: vehicle immobilizer key from other vehicles, keyless access transmitters from other vehicles, interstate/bridge toll passes, gate passes, community/parking access cards, fuel station speed passes, and building access swipe cards/ transponder devices. See images below for examples of RFID devices

Object ID: 2773315Click here for detailed picture of the image.

Recommendation/Instructions
Important: Do not replace any parts for this concern prior to duplicating the concern and reviewing the following information

It is possible that a RFID device may interfere with the vehicle's Passkey theft system. The range of the interference can vary based on the strength of the RFID which can affect the key to exciter module communication. All sets of keys should be inspected for such RFID devices. The customer may be removing the RFID device, from the key ring, when dropping the vehicle off for service. If you are unable to duplicate the concern review this information with the customer and ask if they use any search RFID devices. These RFID devices will need to be removed from the key ring.

Also, verify the vehicle owner is not inducing the concern by flipping the key while cranking, see the latest version of PIT5030 for vehicle that apply.

For vehicles with passive entry/start, it is possible to get RFI from transponders or other frequency emitting devices in the area. An RFI meter is available from the aftermarket that can be utilized as an aid to locate the stray RFI signals, See Photo Below For image of the meter.

 

[GodFearinGunTotin]

This is a long one and unfortunately, it's got a bunch of photos and drawings embedded in it. The good thing, is it's for an intermittent no crank and it's got a couple of your DTCs in it.

Some customers may comment on any of the following conditions:

•The malfunction indicator lamp (MIL) may be illuminated.
•Instrument panel cluster (IPC) warning lamps may illuminate.
•The transmission may not shift or defaults to 2nd gear.
•The door locks may cycle by themselves.
•The engine may not crank intermittently.
•Engine may stall (applies to Corvette, Hybrid Full Size Truck models)
•A driver information center (DIC) message may be displayed.
•The IPC gages may fluctuate.
•Applying the brakes may cause the IPC to become erratic and the chimes to operate simultaneously.
•Engine cooling fan runs continuously causing dead 12v Battery.
•Malfunction Indicator Lamp flickers or is dim.
Depending on the vehicle and build, technicians may find one or more, but not limited to the following, High Speed GMLAN Communication DTCs set as Current or History:

•P0700: Transmission Control Module (TCM) Requested MIL Illumination
•U0073: Control Module Communications Bus OFF
•U0100: Lost Communication With ECM/PCM
•U0101: Lost Communication With Transmission Control Module (TCM)
•U0102: Lost Communication with Transfer Case Control Module (TCCM)
•U0109: Lost Communication With Fuel Pump Control Module
•U0121: Lost Communication With ABS Control Module
•U0140: Lost Communication With Body Control Module (BCM)
•U186B: Lost Communication With TCM
•U0129 : Lost Communication with Brake System Control Module
•U186B: Lost Communication with TCM
•U0293: Lost Communication with HP2 Powertrain Control Module
•U1862: Battery Energy Control Module Lost Communication with Communications Gateway Module
•U1876: Drive Motor Control Module A Lost Communication With Engine Control Module (ECM)
•U1879: Drive Motor Control Module B Lost Communication With Engine Control Module (ECM)
•U1886: Battery Energy Control Module Lost Communication with Engine Control Module (ECM)
•U1888: Hybrid Powertrain Control Module Lost Communication With Starter/Generator Control Module
Cause
These conditions may be caused by, but not limited to, any of the following:

•Chafed, damaged, pinched, open or shorted wiring.
•The terminal(s) for the High Speed GMLAN Serial Data Bus has or have backed out of the 16-way electrical connector to the automatic transmission.
•The terminal position assurance (TPA) lock in the transmission 16-way electrical connector is not fully seated.
•The High Speed GMLAN Serial Data Bus circuits are open or shorted to ground.
•Corrosion in a control module connector.
•Intermittent or poor connections in the inline connectors containing the High Speed GMLAN Serial Data Bus circuits.
•Water intrusion in a control module connector.
Note: Model Year 2007 vehicles.

•The Terminator Resistor is open or shorted.
Note: Model Year 2008 Sierra and Silverado vehicles.

•The Data Link Resistor is open or shorted.
Note: Model Year 2009 and newer Sierra and Silverado vehicles.

•The Data Link Resistor 1 is open or shorted.
Note: Model Year 2008 and newer Avalanche, Escalade, Tahoe, Yukon vehicles.

•The Data Link Resistor 1 is open or shorted.
Note: Model Year 2008 and newer Hybrid RPO HP2 vehicles.

•The Data Link Resistor 2 (RPO HP2) is open or shorted.
Note: The following cause only pertains to hybrid RPO HP2 vehicles equipped with OnStar® Delete RPO UE0.

•The High Speed GMLAN jumper harness loop connector that plugs into the bottom rear of the interior driver side junction block, is open or shorted from chafing on the IP brace.
Correction
Note: As of the 2015 calendar year, the Data Bus Diagnostic Tool is available to assist in diagnosing issues with High Speed LAN. Refer to the Data Bus Diagnostic Tool User Guide, available in SI under Select and View a User Guide on the base screen. If after using the Data Bus Diagnostic Tool, the cause of the issue has not been found, continue with this bulletin which covers common areas of possible concern.

Do This
Don't Do This

Repair or replace any backed out or damaged transmission connector terminal(s) as necessary.
DO NOT replace any control module, wiring harness or component until you have first isolated the cause of the condition or followed this procedure in its entirety.

Ensure that the transmission connector TPA is fully seated (TPA is centered in check window).

Repair the High Speed GMLAN Serial Data Bus circuits that are open, shorted to ground or have poor connections.

Repair the corrosion or water intrusion condition in the affected module connector.

Replace the Terminator Resistor that is open or shorted.

Replace the Data Link Resistor 1 or Data Link Resistor 2 (RPO HP2 vehicles only) that is open or shorted.

Repair the junction block jumper harness loop connector wiring that is open or shorted. (RPO HP2 Vehicles equipped with OnStar® Delete RPO UE0 Only).


Information for the Procedures to Diagnose and Repair the Above Conditions
 1. Perform the Diagnostic System Check-Vehicle to begin your diagnosis.
 2. Perform a thorough visual inspection of the vehicle.
 3. Depending on the vehicle and vehicle build, some of the procedures may not be applicable.
Note: The following procedure is the only one applicable to the Corvette and XLR.

Chafed Wiring Harness at Transmission Case Retaining Clip and Inspection of the 16-way Electrical Connector for Backed Out Terminals
Note: This is the Only procedure which applies to Corvette and XLR.

 1. Turn OFF the ignition and all accessories.
 2. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in SI.
Object ID: 2043302Click here for detailed picture of the image.

Object ID: 2043303Click here for detailed picture of the image.

 3. Locate the 16-way electrical connector on the right side of the automatic transmission as shown.
 4. Inspect for chafed, damaged, pinched, open or shorted wiring within the conduit of the harness where it is secured at the transmission by a metal attachment clip as shown. Inspect any wiring harness where these metal attachment clips are used on the vehicle as needed.
⇒ If the wiring is damaged, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures in SI. Protect the conduit by covering any sharp edge with butyl tape and the conduit and wiring harness with woven polyester (PET) electrical tape. Secure the harness as needed.
Object ID: 2807959Click here for detailed picture of the image.

 5. Before disconnecting the 16-way connector, inspect for any backed out terminals (1) as shown. Fully seated terminals (2,3) are shown for comparison.
5.1. If a backed out terminal (1) is found, identify the terminal(s) on the repair order.
5.2. Look at the connector in order to identify the number of the cavity with the backed out terminal. Refer to Wiring Systems and Power Management > Component Locator > Master Electrical Component List in SI.
Object ID: 1921876Click here for detailed picture of the image.

Note: For 2ML70 Only: Disconnect the 4WAL electrical connector.

 6. Use the following procedure to disconnect the 16-way electrical connector:
6.1. Release and hold the slide lock on the wiring harness connector.
6.2. Rotate the connector lever and remove the connector from the component.
Object ID: 2807963Click here for detailed picture of the image.

 7. Inspect for any backed out terminals (3) as shown. Fully seated terminals (1,2) are shown for comparison.
7.1. If a backed out terminal (3) is found, identify the terminal(s) on the repair order.
7.2. Look at the connector in order to identify the number of the cavity with the backed out terminal. Refer to Wiring Systems and Power Management > Component Locator > Master Electrical Component List in SI.
 8. Repair or replace the terminal(s) as necessary using the following procedure:
Object ID: 1921872Click here for detailed picture of the image.

8.1. Locate the terminal position assurance (TPA) as shown.
Note: The TPA cannot be removed from the connector while there are terminals present in the connector body.

Object ID: 1921873Click here for detailed picture of the image.

8.2. Use a small flat blade tool to push the TPA until it bottoms out.
Object ID: 1921843Click here for detailed picture of the image.

8.3. See the release tool cross reference in the Reference Guide of the J-38125 to ensure that the correct release tool is used. Use the J-38125-28 tool to release the terminals by inserting the tool into the terminal cavity as shown.
8.4. While holding the removal tool in place, gently pull the wire out of the back of the connector.
Note: If the female terminal(s) must be replaced, it is part number 22124472200. It is located in Yazaki tray number 12 in the J-38125 Terminal Repair Kit.

8.5. Repair or replace the terminal(s) as needed. Refer to the instructions in the J-38125 manual.
 9. If the wiring is damaged, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures in SI.
10. Slide the new terminal(s) into the correct cavity at the back of the connector until it locks in place. The new terminal(s) should be even with the other terminal(s).
11. Ensure that each terminal is locked in place by gently pulling on the wire.
Note: The male terminal(s) cannot be repaired as they are an integral part of the transmission control module (TCM).

12. Inspect for bent or misaligned terminal(s) in the transmission half of the electrical connector.
⇒ If they are bent, use a suitable tool and apply gentle pressure to straighten them. Indicate on the repair order the terminal number that was bent.
⇒ If they are damaged, replace the TCM. Refer to Control Solenoid Valve and Transmission Control Module Assembly Replacement in SI.
13. Prior to installing the transmission connector, perform the following steps to ensure that the TPA lock is fully seated.
Object ID: 2089334Click here for detailed picture of the image.

Locate the TPA lock in the reassembled transmission connector. Refer to the arrow in the illustration above, which points to a TPA lock. This one is in an unseated position. Using a small flat blade tool, push to seat the TPA until it bottoms out. Verify the TPA is fully seated.

Object ID: 2089456Click here for detailed picture of the image.

◦If the TPA is off-center in the check window as shown, then it is only partially seated. Note the large gap at the arrow. Reseat the TPA lock and ensure that it is fully seated.
Object ID: 2089400Click here for detailed picture of the image.

◦If the TPA lock is centered in the window as shown, then it is fully seated. The gaps shown by the arrows should be even on both sides.
Note: For 2ML70 Only: Connect the 4WAL electrical connector.

14. Connect the 16-way electrical connector to the transmission.
15. Lower the vehicle.
16. Clear any DTCs that may be present with a scan tool and verify the proper operation of the vehicle.
Multiple Wires Cut and/or Corroded Due to Contact Between the Engine Wiring Harness and the Right Front Brake Pipe on the Left Front Frame Rail
 1. Turn OFF the ignition and all accessories.
 2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in SI.
Object ID: 4216940Click here for detailed picture of the image.
(1) Engine Harness

Object ID: 4216944Click here for detailed picture of the image.
(2) Brake Pipe That’s Subject to Rubbing

 3. Inspect for chafed, damaged, pinched, open or shorted wiring on the engine harness in areas illustrated above.
⇒ If the wiring is damaged, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures in SI. Protect the harness by covering any sharp edge with butyl tape and the harness with woven polyester (PET) electrical tape. Secure the harness as needed.
 4. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in SI.
 5. Clear any DTCs that may be present with a scan tool and verify the proper operation of the vehicle.
Inspection of Fuse Block - I/P (Left Side) for Loose Connector X1
 1. Turn OFF the ignition and all accessories.
 2. Disconnect the negative battery cable. Refer to Battery Disconnect Caution and Battery Negative Cable Disconnection and Connection in SI.
Object ID: 386487Click here for detailed picture of the image.

 3. Remove the left side fuse block as shown.
Object ID: 2077437Click here for detailed picture of the image.

 4. Inspect connector X1 (1) on the back of the fuse block for a loose connection. Secure the connector as needed.
 5. Install the left side fuse block.
 6. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in SI.
 7. Clear any DTCs that may be present with a scan tool and verify the proper operation of the vehicle.
Chafed IP Wiring Harness Near Park Brake Pedal Assembly
The above condition may cause one or more of the following fuses to open:

•60A - MBEC1 (#72) (Underhood)
•30A - AMP (#40) (Underhood)
•15A - RDO (#41) (Underhood)
•10A - IPC (#46) (Underhood)
•15A - AIR BAG BATT (#51) (Underhood)
•10A - DSM (Left side of IP)
Five areas of potential contact have been identified:


Object ID: 2002643Click here for detailed picture of the image.

•The IP wiring branch to C202 may have been routed outboard of the junction block (left IP) and the retaining clip (1) off the branch may not have been fully seated. Possible point of contact (2).
Object ID: 2002646Click here for detailed picture of the image.

•The IP wiring branch to C202 may have been pushed up and forward into the park brake assembly and the retaining clip off the branch may not have been fully seated. Possible points of contact (1, 2).
Object ID: 2002647Click here for detailed picture of the image.

•The IP wiring branch to C202 may not have been secured into place as the gray retaining clip (1) off the branch was never seated.
Object ID: 2002648Click here for detailed picture of the image.

•The IP harness may be in hard contact with the top rear edge (1) of the park brake assembly.
Object ID: 2002649Click here for detailed picture of the image.

•When releasing the park brake pedal, the moving part (1) at the end of the park brake release cable may be coming into hard contact with the IP harness.
If a condition is suspected or found with one of the circuits running to C1 or C2 of the junction block or to the inline IP-to-body connector C202 or at any of these areas of concern then remove the front driver side door sill plate, driver side body hinge pillar trim panel, left IP outer trim cover and perform the following steps:

 1. Turn OFF the ignition and all accessories.
 2. Inspect the IP harness for chafed, damaged, pinched, open or shorted wiring at the park brake pedal assembly. Refer to the potential damage points as shown in the photos - at the side and rear of the park brake assembly. Be advised that damage may be covered by electrical tape, or turned away and hid from view.
 3. Engage and release the park brake several times. Observe the moving part at the end of the park brake release cable as it may contact and damage the IP harness. Inspect the IP harness at this possible contact point. Note that any damage may be covered by electrical tape and/or hid from view.
⇒ If the wiring is damaged, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures in SI. Protect the harness by covering any sharp edge with butyl tape and the harness with woven polyester (PET) electrical tape.
Engage and release the park brake several times. Verify the harness is no longer making contact with any sharp edge or point of the park brake assembly. If it is still making contact, route it away from the contact point and secure it with tie straps.

Proceed to Step 4.

Object ID: 2002644Click here for detailed picture of the image.

 4. Inspect how the IP branch to C202 is routed. Route the harness as necessary to match the correct routing in the photo as shown. In order to route the IP harness branch correctly (behind the junction block-left I/P), remove the cover from the junction block-left I/P and unseat the junction block from the bracket.
 5. Disconnect C202. Route the harness so that it lies between the "goalposts" of the junction block bracket. Seat the junction block to the bracket. The harness will now be under the junction block.
 6. Secure the harness by seating the grey offset retaining clip to the dashmat (or brown "buddy clip" if present - usually on SUV's only). Reconnect C202.
 7. Clear any DTCs that may be present with a scan tool and verify the proper operation of the vehicle.
Chafed IP Wiring Harness at Left Side Junction Block Mounting Bracket
 1. Turn OFF the ignition and all accessories.
 2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in SI.
 3. Remove the left side junction block. Refer to Instrument Panel Electrical Center or Junction Block Replacement - Left Side in SI.
 4. Inspect for chafed, damaged, pinched, open or shorted wiring at the mounting bracket.
⇒ If the wiring is damaged, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures in SI. Protect the harness by covering any sharp edge with butyl tape and the harness with woven polyester (PET) electrical tape. Secure the harness as needed.
 5. Replace the left side junction block. Refer to Instrument Panel Electrical Center or Junction Block Replacement - Left Side in SI.
 6. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in SI.
 7. Clear any DTCs that may be present with a scan tool and verify the proper operation of the vehicle.
Chafed Wiring Harness at Adjustable Pedals Motor
 1. Turn OFF the ignition and all accessories.
Object ID: 2264518Click here for detailed picture of the image.

 2. Inspect for chafed, damaged, pinched, open or shorted wiring at the adjustable pedals motor as shown.
 3. If the wiring is damaged, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures in SI. Protect the conduit by covering any sharp edge with butyl tape and the harness with woven polyester (PET) electrical tape. Secure the harness as needed.
 4. Clear any DTCs that may be present with a scan tool and verify the proper operation of the vehicle.
Chafed Wiring Harness at Transmission
 1. Turn OFF the ignition and all accessories.
 2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in SI.
 3. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in SI.
 4. Support the transmission with a transmission jack.
 5. Remove the transmission support crossmember. Refer to Transmission Support Crossmember Replacement in SI.
Object ID: 2434892Click here for detailed picture of the image.

 6. Lower the transmission sufficiently to provide access to the engine wiring harness where it routes from the engine intake manifold to the transmission bell housing as shown.
 7. Release the wiring harness conduit from the retainers that secure it to the transmission and/or transfer case.
Object ID: 2435124Click here for detailed picture of the image.

Object ID: 2435234Click here for detailed picture of the image.

 8. Examine the harness for wiring that may be exposed outside of the conduit. Inspect all areas for chafed, damaged, pinched, open or shorted wiring as shown. If damage to the wiring is not observed, then extract the wiring from the conduit and inspect all remaining areas as needed.
⇒ If the wiring is damaged, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures > Wiring Repairs in SI. Protect the conduit by covering any sharp edge with butyl tape and the harness with woven polyester (PET) electrical tape. Secure the harness as needed.
 9. Raise the transmission as needed to install the transmission support crossmember. Refer to Transmission Support Crossmember Replacement in SI.
10. Lower the vehicle.
11. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in SI.
12. Clear any DTCs that may be present with a scan tool and verify the proper operation of the vehicle.
Chafed ECM Wiring Harness From Bracket Contact Near Engine Intake Manifold
 1. Turn OFF the ignition and all accessories.
 2. Remove the upper intake manifold sight shield. Refer to Upper Intake Manifold Sight Shield Replacement in SI.
Object ID: 2808042Click here for detailed picture of the image.

 3. Locate the portion of the engine wiring harness where it branches off from the intake manifold to the ECM in the area shown (1).
Object ID: 2808049Click here for detailed picture of the image.

 4. Inspect the wiring harness for damage from contact with the steel bracket (1).
⇒ If the wiring is damaged, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures > Wiring Repairs in SI.
 5. Cover any sharp edge on the bracket with butyl tape and the harness with woven polyester (PET) electrical tape.
Object ID: 2808054Click here for detailed picture of the image.

 6. Protect the wiring harness by adding additional conduit (2) as shown. Tape the conduit to the harness at both ends (1,3) to prevent movement.
 7. Secure the harness to the bracket with a retaining clip (4) as needed.
Chafed Wiring Harness at Rear of Engine Intake Manifold
 1. Turn OFF the ignition and all accessories.
 2. Remove the upper intake manifold sight shield. Refer to Upper Intake Manifold Sight Shield Replacement in SI.
Object ID: 2808697Click here for detailed picture of the image.

 3. Remove the retaining plate (2) that covers the wiring harness (1) on the top of the engine intake manifold run channel.
Object ID: 2808687Click here for detailed picture of the image.

 4. Gently release and slightly raise the wiring harness (2) from the run channel (1) to allow some slack in the harness.
Object ID: 2808134Click here for detailed picture of the image.

 5. Release the wiring harness conduit from the retainers that secure it to the rear of the engine and at the top of the transmission bell housing.
Object ID: 2328025Click here for detailed picture of the image.

Note: The engine intake manifold is shown removed to provide clarity.

 6. Gently pull the wiring harness (2) up from the rear of the engine (1).

Object ID: 2328026Click here for detailed picture of the image.

Inspect for chafed (1), damaged, pinched, open or shorted wiring. If damage is not observed, then extract the wiring from the conduit and inspect all of the remaining areas as needed.

⇒ If the wiring is damaged, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures.
 7. Protect the conduit by covering any sharp edges on the engine or transmission with butyl tape and the harness with woven polyester (PET) electrical tape.
 8. Secure the wiring harness within the conduit as needed.
 9. Attach the wiring harness conduit to the retainers that secure it to the rear of the engine and at the top of the transmission bell housing.
Object ID: 2808687Click here for detailed picture of the image.

10. Secure the wiring harness (2) within the engine intake manifold run channel (1).
Object ID: 2808712Click here for detailed picture of the image.

⇒ If the vehicle has a small engine wiring harness bundle, secure a portion of the harness within some conduit (1) in the area that will be covered by the retaining plate to prevent movement.
11. Tape both ends of the conduit (1) to the wiring harness.
Object ID: 2808697Click here for detailed picture of the image.

12. Install and secure the retaining plate (2) over the top of the wiring harness bundle (1).
13. Install the upper intake manifold sight shield.
14. Clear any DTCs that may be present with a scan tool and verify the proper operation of the vehicle.
Chafed Wiring Harness at Chassis Body Mounts Left Side Frame Rail
 1. Turn OFF the ignition and all accessories.
 2. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in SI.
Object ID: 2268656Click here for detailed picture of the image.

 3. Inspect the wiring harness along the left side frame rail at the body mounts as shown for chafed, damaged, pinched, open or shorted wiring.
 4. If the wiring is damaged, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures. Protect the conduit by covering any sharp edge with butyl tape and the harness with woven polyester (PET) electrical tape. Secure the harness as needed.
 5. Lower the vehicle.
 6. Clear any DTCs that may be present with a scan tool and verify the proper operation of the vehicle.
GMLAN Terminator Resistor 2007 Vehicles
 1. Turn OFF the ignition and all accessories.
 2. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in SI.
Typical Location of Terminator Resistor (1) Short Wheel Base Vehicle

Object ID: 2653761Click here for detailed picture of the image.
Typical Location of Terminator Resistor (1) Long Wheel Base Vehicle - RPO NQZ

Object ID: 2658551Click here for detailed picture of the image.
Typical Location of Terminator Resistor (1) Long Wheel Base Vehicle - Except RPO NQZ

Object ID: 2658600Click here for detailed picture of the image.

Note: RPO NQZ Without Auxiliary Fuel Tank.

 3. On the vehicle being serviced, observe the location of the terminator resistor. Inspect the wiring harness leading to the terminator resistor, for chafed, damaged, pinched, open or shorted wiring.
⇒ If the wiring is damaged, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures. Protect the conduit by covering any sharp edge with butyl tape and the harness with woven polyester (PET) electrical tape. Secure the harness as needed.
⇒ If the wiring is not damaged, proceed to Step 4.
 4. Disconnect the electrical connector from the terminator resistor.
 5. Test the terminator resistor for 110–130Ω.
⇒ If the resistance is not within the specified range, replace the terminator resistor and proceed to Step 6.
⇒ If the resistance is within the specified range, connect the electrical connector to the terminator resistor. Refer to Power and Signal Distribution > Data Communications > Scan Tool Does Not Communicate with High Speed GMLAN Device OR Diagnostic Trouble Code (DTC) List - Vehicle in SI.
 6. Connect the electrical connector to the terminator resistor. Secure the terminator resistor as needed.
 7. Lower the vehicle.
 8. Clear any DTCs that may be present with a scan tool and verify the proper operation of the vehicle.
Data Link Resistor 1 2009 Vehicles
 1. Turn OFF the ignition and all accessories.
 2. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in SI.
Typical Location of Data Link Resistor 1 (1) Short and Long Wheel Base Vehicles

Object ID: 2658245Click here for detailed picture of the image.
Typical Location of Data Link Resistor 1 (1) Long Wheel Base HD Vehicles

Object ID: 2658490Click here for detailed picture of the image.

 3. On the vehicle being serviced, observe the location of the data link resistor 1 (1). Inspect the wiring harness leading to the data link resistor 1, for chafed, damaged, pinched, open or shorted wiring.
⇒ If the wiring is damaged, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures. Protect the conduit by covering any sharp edge with butyl tape and the harness with woven polyester (PET) electrical tape. Secure the harness as needed.
⇒ If damage is not found, proceed to Step 4.
 4. Disconnect the electrical connector from the data link resistor 1.
 5. Test the Data Link Resistor 1 for 110–130Ω.
⇒ If the resistance is not within the specified range, replace the data link resistor 1 and proceed to Step 6.
⇒ If the resistance is within the specified range, connect the electrical connector to the data link resistor 1. Refer to Power and Signal Distribution > Data Communications > Scan Tool Does Not Communicate with High Speed GMLAN Device OR Diagnostic Trouble Code (DTC) List - Vehicle in SI.
 6. Connect the electrical connector to the data link resistor 1. Secure the data link resistor 1 as needed.
 7. Lower the vehicle.
 8. Clear any DTCs that may be present with a scan tool and verify the proper operation of the vehicle.
Rear Chassis Mounted Data Link Resistor 1 Chafed Wiring Harness Causing Intermittent No/Crank and/or Scan Tool Does Not Communicate with High Speed GMLAN Device
 1. Turn OFF the ignition and all accessories.
 2. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in SI.
Object ID: 2651339Click here for detailed picture of the image.

 3. Typical location of a data link resistor 1 (1) mounted on the rear of the chassis.
Object ID: 1991762Click here for detailed picture of the image.

 4. Inspect the wiring harness leading to the rear data link resistor 1, between the truck box and frame for chafed, damaged, pinched, open or shorted wiring as shown.
⇒ If the wiring is damaged, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures. Protect the conduit by covering any sharp edge with butyl tape and the harness with woven polyester (PET) electrical tape. Secure the harness as needed. Proceed to Step 9.
⇒ If the wiring is not damaged, proceed to Step 5.
 5. Disconnect the electrical connector from the data link resistor 1.
 6. Test the data link resistor 1 for 110–130Ω.
⇒ If the resistance is not within the specified range, replace the data link resistor 1 and proceed to Step 7.
⇒ If the resistance is within the specified range, connect the electrical connector to the data link resistor 1. Refer to Power and Signal Distribution > Data Communications > Scan Tool Does Not Communicate with High Speed GMLAN Device OR Diagnostic Trouble Code (DTC) List - Vehicle in SI.
 7. Connect the electrical connector to the data link resistor 1. Secure the resistor as needed.
 8. Protect the conduit by covering any sharp edge with butyl tape and the harness with woven polyester (PET) electrical tape. Secure the harness as needed.
 9. Lower the vehicle.
10. Clear any DTCs that may be present with a scan tool and verify the proper operation of the vehicle.
Inspection of Engine Harness Connector X109 for Backed Out or Bent Terminals and Poor Connections
 1. Turn OFF the ignition and all accessories.
 2. Locate the X109 connector. Refer to Wiring Systems and Power Management > Component Locator > Master Electrical Component List > X109 in SI.
Object ID: 2264519Click here for detailed picture of the image.

 3. Before disconnecting, verify the connector is fully seated together even though the lever is locked down as shown.
If the connector is not fully seated, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures > Connector Repairs in SI.

 4. Inspect the connector for the following conditions:
◦Backed out terminals
◦Bent pins
◦Corrosion
◦Poor terminal tension (use the correct test probe)
⇒ If a condition is found, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures in SI.
AND

⇒ If corrosion is found, proceed to the section of the bulletin titled: Repairing Fretting Corrosion to complete the repair.
 5. Clear any DTCs that may be present with a scan tool and verify the proper operation of the vehicle.
Inspection of Engine Harness Connector X115 for Backed Out or Bent Terminals and Poor Connections
 1. Turn OFF the ignition and all accessories.
 2. Locate the X115 connector. Refer to Wiring Systems and Power Management > Component Locator > Master Electrical Component List > X115 in SI.
 3. Inspect the connector for the following conditions:
◦Backed out terminals
◦Bent pins
◦Corrosion
◦Poor terminal fit (use the correct test probe)
⇒ If a condition is found, repair as needed. Refer to Wiring Systems and Power Management > Diagnostic Information and Procedures in SI.
AND

⇒ If corrosion is found, proceed to the section of the bulletin titled: Repairing Fretting Corrosion to complete the repair.
 4. Clear any DTCs that may be present with a scan tool and verify the proper operation of the vehicle.
Hybrid Models (HP2) Chafed Wiring Harness Locations and Inspection of Engine Harness Connector X150 for Backed Out Terminals and/or Poor Connections at Ground Locations G102 and G300
 1. Turn OFF the ignition and all accessories.
 2. Locate the X150 connector. Refer to Wiring Systems and Power Management > Component Locator > Master Electrical Component List > X150 in SI.
 3. Inspect the connector for the following conditions:
◦Backed out terminals
◦Bent pins
◦Corrosion
◦Poor terminal fit (use the correct test probe)
⇒ If a condition is found, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures in SI.
AND

⇒ If corrosion is found, proceed to the section of this bulletin titled: Repairing Fretting Corrosion to complete the repair.
⇒ If a condition or corrosion is not found, proceed to Step 4.
Object ID: 2297689Click here for detailed picture of the image.

 4. Inspect for a misrouted harness having chafed, damaged, pinched, open or shorted wiring from rubbing on the cooling fins of the Transmission Auxiliary Fluid Pump Control Module as shown.
⇒ If the wiring is damaged, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures in SI. Protect the conduit by covering any sharp edge with butyl tape and the harness with woven polyester (PET) electrical tape. Secure the harness as needed. Proceed to Step 8.
⇒ If the wiring is not damaged, proceed to Step 5.
Object ID: 2305639Click here for detailed picture of the image.

 5. Inspect for chafed, damaged, pinched or shorted wiring caused by a mispositioned harness retaining clip as shown. This condition usually occurs when the tab of the clip is aligned with a slot in the conduit.
⇒ If the wiring is damaged, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures in SI. Protect the conduit by covering any sharp edge with butyl tape and the harness with woven polyester (PET) electrical tape. Secure the harness as needed. Proceed to Step 8.
⇒ If the wiring is not damaged, proceed to Step 6.
 6. Locate ground connections G102 and G300. Refer to Wiring Systems and Power Management > Component Locator > Master Electrical Component List > G102 and G300 in SI.
 7. Inspect G102 and G300 for a clean and tight connection. Undercoating or corrosion may be present between the eyelet and the frame resulting in a poor connection.
⇒ If a poor connection or undercoating is found, clean the area and repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures in SI.
Proceed to Step 8.

⇒ If corrosion is found, clean the area and repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures in SI. Proceed to the section of this bulletin titled: Repairing Fretting Corrosion to complete the repair.
 8. Clear any DTCs that may be present with a scan tool and verify the proper operation of the vehicle.
Hybrid Models (RPO HP2) Data Link Resistor 2
 1. Turn OFF the ignition and all accessories.
Object ID: 2652658Click here for detailed picture of the image.

 2. Inspect the harness leading to the data link resistor 2 (1) for chafed, damaged, pinched, open or shorted wiring. Refer to Power and Signal Distribution > Data Communications > Schematic and Routing Diagrams > Data Communication Schematics.
⇒ If the wiring is damaged, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures. Protect the conduit by covering any sharp edge with butyl tape and the harness with woven polyester (PET) electrical tape. Secure the harness as needed.
⇒ If the wiring is not damaged, proceed to Step 3.
 3. Disconnect the electrical connector from the data link resistor 2.
 4. Test the data link resistor 2 for 110–130Ω.
⇒ If the resistance is not within the specified range, replace the data link resistor 2 and proceed to Step 5.
⇒ If the resistance is within the specified range, connect the electrical connector to the terminator resistor. Refer to Power and Signal Distribution > Data Communications > Scan Tool Does Not Communicate with High Speed GMLAN Device OR Diagnostic Trouble Code (DTC) List - Vehicle in SI.
 5. Connect the electrical connector to the data link resistor 2. Secure the resistor as needed.
 6. Clear any DTCs that may be present with a scan tool and verify the proper operation of the vehicle.
Hybrid Models (HP2) Equipped With OnStar® Delete RPO UE0 — IP Junction Block Jumper Harness Loop Connector Chafed Wiring
Various Symptoms and/or Powertrain and Communication DTCs Set

The following is a list of some of the DTCs that may be set and is not all inclusive: C0242, P0700, P0AC4, U0293, U0100, U0109, U0129, U0140, U1862, U186B, U1886 or U1888.


 1. Turn OFF the ignition and all accessories.
 2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in SI.
Object ID: 2658675Click here for detailed picture of the image.

 3. Locate the junction block (1) on the driver side of the vehicle under the instrument panel (IP).
Object ID: 2658705Click here for detailed picture of the image.

 4. Locate the jumper harness loop connector that plugs into the bottom back of the junction block.
Object ID: 2658869Click here for detailed picture of the image.

 5. Inspect the jumper harness loop connector (1) for chafed (2), damaged, pinched, open or shorted wiring from contact with the IP brace.
⇒ If the wiring is damaged, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures in SI. Protect the harness by covering any sharp edge with butyl tape and the harness with woven polyester (PET) electrical tape. Secure the jumper harness loop connector as needed. Proceed to Step 6.
⇒ If the wiring is not repairable, replace the P/N 15127940 jumper harness loop connector. Protect the connector by covering any sharp edge with butyl tape and the jumper harness loop connector wiring with woven polyester (PET) electrical tape. Secure the harness as needed. Proceed to Step 6.
 6. Secure the junction block as needed.
 7. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in SI.
 8. Clear any DTCs that may be present with a scan tool and verify the proper operation of the vehicle.
Lost Communication with Various Control Modules and DTCs Set
DTC Descriptors
Note: Depending on the vehicle and vehicle build there may be other DTCs set by other modules.

•DTC U0073 Control Module Communication Bus A Off
•DTC U0100 Lost Communication with Engine/Powertrain Control Module (ECM/PCM)
•DTC U0101 Lost Communication with Transmission Control Module (TCM)
•DTC U0102 Lost Communication with Transfer Case Control Module
•DTC U0121 Lost Communication with Electronic Brake Control Module (EBCM)
•DTC U0140 Lost Communication with Body Control Module (BCM)
 1. Connect a scan tool and perform the Diagnostic System Check – Vehicle. Retrieve and record any DTCs, Current or in History from all of the control modules.
If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List – Vehicle to identify the connector(s) of the control module/component which may be causing the condition.

 2. Turn OFF the ignition and all accessories.
 3. Disconnect the connector(s) at the affected module.
 4. Inspect the connector(s) for the following conditions:
◦Backed out terminals
◦Bent pins
◦Corrosion
◦Poor terminal tension. Use the correct test probe.
◦Water intrusion
⇒ If a condition is found, repair as needed. Refer to Power and Signal Distribution > Wiring Systems and Power Management > Diagnostic Information and Procedures in SI.
Proceed to Step 5.

⇒ If corrosion or water intrusion is found, proceed to the section of this bulletin titled: Repairing Fretting Corrosion to complete the repair.
 5. Reconnect the connector at the affected module.
 6. Clear any DTCs that may be present with a scan tool and verify the proper operation of the vehicle.
Inspection of Electronic Suspension Control (ESC) Module Connector for Missing Weather Plugs in Not Used Cavities (RPO Z55 or G69)
 1. Turn OFF the ignition and all accessories.
Typical Location of ESC Module

Object ID: 2664329Click here for detailed picture of the image.

 2. Locate the ESC module (1).
 3. Disconnect the connector (2) at the ESC module (1).
Typical View of Missing Weather Plug

Object ID: 2664512Click here for detailed picture of the image.

 4. Inspect the connector of the ESC module for weather plugs that are missing from: Not Used cavities (1). Refer to > Power and Signal Distribution > Wiring Systems and Power Management > Component Locator > Master Electrical Component List > Electronic Suspension Control (ESC) Module > Connector End View for a list of cavities that are: Not Used.
⇒ If a weather plug is missing from any Not Used cavity, repair as needed.
 5. Install the connector (2) to the ESC module (1).
 6. Clear any DTCs that may be present with a scan tool and verify the proper operation of the vehicle.
Repairing Fretting Corrosion
Note: Fretting corrosion looks like little dark smudges on the electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass.

 1. If water intrusion is observed in the connector, use pressure regulated compressed air to dry it out.
Object ID: 2214281Click here for detailed picture of the image.

 2. DO NOT apply an excessive amount of dielectric lubricant as shown, to the connectors as hydrolock may result when attempting to mate the connectors. This could cause terminals to back out, resulting in an intermittent connection.
Important: Use ONLY a clean nylon brush that is DEDICATED to the repair of this specific condition.

Using a one-inch or smaller nylon bristle brush, apply dielectric lubricant P/N 12377900 (in Canada P/N 10953529) to both the module or component side and the harness side of the affected connectors.

 3. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present.
 4. If needed, connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in SI.
 5. Clear any DTCs that may be present with a scan tool and verify the proper operation of the vehicle.
OnStar is a registered trademark of the OnStar Corporation.

 

[GodFearinGunTotin]

Finally, there's this. It doesn't have any of your DTCs and it says "potential" no crank. It's got some tables and stuff in it so, I'll just post the first part. I can email you a pdf if you really want it.

Subject: Diagnostic Information for MIL Illuminated with DTC P1825, P182E or P1915 Found Current or as History Code in TCM, No PRNDL Display, Potential No Engine Crank

Models: 2006-2009 Cadillac XLR-V
2006-2010 Cadillac STS-V
2007-2009 Cadillac SRX, XLR
2007-2010 Cadillac Escalade, Escalade ESV, Escalade EXT, STS
2008-2010 Cadillac CTS
2009-2010 Cadillac CTS-V
2006-2010 Chevrolet Corvette
2007-2010 Chevrolet Silverado
2008-2010 Chevrolet Suburban
2009-2010 Chevrolet Avalanche, Tahoe
2010 Chevrolet Camaro, Express
2007-2010 GMC Sierra, Yukon Denali, Yukon XL Denali
2008-2010 GMC Yukon XL
2009-2010 GMC Yukon
2010 GMC Savana
2008-2009 Pontiac G8
2008-2009 HUMMER H2
with 6L50 RPO MYB, 6L80 RPO MYC or 6L90 RPO MYD Automatic Transmission

--------------------------------------------------------------------------------

This bulletin is being revised to remove the contact information in Step 4 under HISTORY DTC heading and update the models and model years. Please discard Corporate Bulletin Number 08-07-30-020D (Section 07 – Transmission).


--------------------------------------------------------------------------------

The following diagnostic information will aid the technician if the MIL is illuminated with DTC P1825, P182E or P1915. The DTC may be found current or as a history code in the TCM along with a no PRNDL display and the potential for no engine crank.

 1. Use the Tech 2® to capture and record Freeze Frame/Failure Data for all DTCs set. Review the data to determine:
◦Vehicle speed, commanded gear, transmission temperature, throttle position, transmission ratio, transmission input and output speed sensor RPM when DTC set (use to attempt to duplicate failure)
◦IMS A/B/C/P and IMS state
 2. Using the Tech 2®, navigate to transmission data and scroll down to IMS. With the ignition ON and the engine OFF, observe the IMS A/B/C/P switch states and IMS states for each shift lever detent position. The chart following this list shows the correct states.
 3. If all IMS readings are normal, monitor the PNP status in the engine data list during DTC setting to isolate a possible open or short to ground on the dedicated PNP signal between the TEHCM and the ECM.
 4. If the vehicle is a 2009 CTS, STS or SRX, proceed to Step 5 in the History DTC section below before continuing with any additional evaluations.
 5. If all IMS and PNP readings are normal, the condition is intermittent in nature and determination of the defective component will be made based on freeze frame data and previous repair history or warranty data. Proceed to History DTC below. If the readings are not as specified above, the fault is still active. Proceed to the Active DTC section below to determine which component(s) is defective.

 

[GodFearinGunTotin]

There were a couple others that really didn't seem to be applicable or helpful, John. If you come up with some other information, I might be able to do some different searches and get some other results.

 

[bobzilla]

Ya, this is my concern. I want to A: Save a buck and B: Help a Small Business along the way. But as mlewis alluded to, I'm afraid Chevy, by design, has the advantage and a quick path to getting my vehicle back in the reliable column.

13 years in dealerships taught me one thing:the buying public is clueless. You say you want to helps small local business, what do you think the dealership is? It's not owned by GM. The dealer has to pay GM for the rights to sell and work on their cars. They have to purchase the tools, provide the building, pay utilities etc. the main difference is they have GM support with access to special tools, training etc. I've seen far too many little shops screw people over to make a buck.

 

[Dirtebiker]

13 years in dealerships taught me one thing:the buying public is clueless. You say you want to helps small local business, what do you think the dealership is? It's not owned by GM. The dealer has to pay GM for the rights to sell and work on their cars. They have to purchase the tools, provide the building, pay utilities etc. the main difference is they have GM support with access to special tools, training etc. I've seen far too many little shops screw people over to make a buck.

And dealer mechanics don't!?

 

[PGRChaplain]

When it does this move the shifter handle, it may be the Neutral Safety Switch. I had this problem on a Chevy Van.

 

[churchmouse]

And dealer mechanics don't!?

Oh they do.....yes they do.

 

[thunderchicken]

I could tell plenty of stories about shady mechanics/shops from small independent shops, used car dealers and oh yes dealerships. Biggest problem is most shops seriously lack in quality control. As a tech I try not to mislead anyone about diagnostics/repairs, doesn't mean I don't mis something now & then. But too many in our industry are just blatant liars and thieves and have no problem screwing people

 

[indyjohn]

Athough I do not work on the commercial side, I do work at a dealer. I would tell you to avoid at all costs. Finding a good technician at a dealership is really hard. Finding one that cares is nearly impossible. Almost none of them that I have talked to actually understand how the components on the vehicle work. They look at a computer and it tells them which parts to change. The guys at the independent shops usually have a better understanding and are willing to go the extra mile where the dealer tech may just give up since it wasn't in the computer. As stated already, the dealer will have access to certain things the independent guys won't. Hope you get this resolved!

THIS is why I've gone back to the Independent, honest work & fair charges.

When it does this move the shifter handle, it may be the Neutral Safety Switch. I had this problem on a Chevy Van.

We've played around with this known problem. Doesn't appear to be the issue.

I could tell plenty of stories about shady mechanics/shops from small independent shops, used car dealers and oh yes dealerships. Biggest problem is most shops seriously lack in quality control. As a tech I try not to mislead anyone about diagnostics/repairs, doesn't mean I don't mis something now & then. But too many in our industry are just blatant liars and thieves and have no problem screwing people

Again, why I've stuck with these people.

So, today, the bad news: It was 20* this morning and the SOB started with not CEL. So now I don't have a repeatable symptom, going into a warm spell so it will be days before I have more data.

GFGT: Thank you sir, I am sending post #29 to them. Maybe that will stir some ideas.

 

[churchmouse]

THIS is why I've gone back to the Independent, honest work & fair charges.



We've played around with this known problem. Doesn't appear to be the issue.



Again, why I've stuck with these people.

So, today, the bad news: It was 20* this morning and the SOB started with not CEL. So now I don't have a repeatable symptom, going into a warm spell so it will be days before I have more data.

GFGT: Thank you sir, I am sending post #29 to them. Maybe that will stir some ideas.

When this happens is the dash dark/no starter or does it light up but will not crank over.
Admit I did not read the entire thread. Heck GFGT's post would put me to sleep.....

 

[indyjohn]

When this happens is the dash dark/no starter or does it light up but will not crank over.
Admit I did not read the entire thread. Heck GFGT's post would put me to sleep.....

Everything is as normal except it doesn't crank. A month ago it would throw a CEL and the next time it would start it would throw "Service Four Wheel Drive", "Service Transfer Case", "Park Assist Off". Obviously the ECM lost contact with the subordinate systems but there is not smoking gun evidence to replace the ECM.

 

[yeti rider]

Auto dealerships are not the only ones with access to OEM level tools and support. As an independent collision repair shop owner, we have people that we work with that have these tools and support. The automobile makers have recently agreed to a "right to repair" act that states they will make available the same repair information and tools to the automotive aftermarket. There are already some OEM's that have a subscription-based way to access OEM repair software for one or two days, a month, or a year. As an independent, it really grinds my gears to hear people say dealers are the only people that can repair things. I apologize I have not helped solve your problem, I'm just getting some info out there. Stick with the guy you trust. You'll get it ironed out.