07 Escalade Lost Communication with BCM After HPT Read

[JHPerformance]

Hey Guys wanted to share my issue and fix from last night. Met a customer at a truck stop to do some tuning on his 07 6.2L Escalade AWD. Plugged my MPVI2 in and started reading the ECM, TCM. Noticed on the dash the message center started displaying service power steering, service air bag. HPT pulled both files and I saved them. We were concerned with battery draining so before editing anything I tried to have him start it, he had a new battery in within 2 weeks old. Truck wouldn't crank. Scanned it, showing loss of communication with BCM. I thought that was weird since all I done was read out. Started checking BCM fuses, clearing codes, tried flashing stock file back in, disabling VATS etc.. asking about aftermarket security etc.. Come to find out there is a software bug in the BCM on the escalades that makes it do a phantom wipe to the BCM after waking up different devices on the CAN bus. It was not my HPT causing the problem, just a software glitch in the BCM. I am guessing when another device gets woken up, it makes the BCM wipe itself.

Pulled up Tech2Win, no communication with BCM on live data. Brought up GM SPS, reprogrammed the BCM and noticed a note under the calibration details "fix for phantom wipe bug" Crazy. Anyways, the BCM took my reprogramming. Went back into the Tech2Win and go into the BCM settings, under module setup click setup SDM primary key in BCM. Turn key off, and back on. Service air bag message is gone. Clear BCM codes, issue resolved.

Programmed the ECM/TCM just like normal and customer left happy.

I found a little info just googling of the same issue, but before you replace the entire BCM like other suggested try a simple BCM reflash with SPS first, it worked for me.

Lesson learned, no more meet and tunes remote. Everyone can come to the shop from now on.

[2xLS1]

I've had random no starts on Gen 4 vehicles over the years after reading/writing and just disconnecting/reconnecting the battery for a bit always fixed them. Same thing with lost communication with TCM errors.

[blindsquirrel]

Do you have a PI/bulletin number for that?

[blindsquirrel]

These are from my offline eSI that hasn't had updates since 2009, these could be superseded many times over by now.

#PIT4007D: Radio Displays LOCKED After SPS Programming - (Aug 11, 2008)

Subject: Radio Displays "LOCKED" After SPS Programming

Models: 2007-2009 Cadillac Escalade, ESV, EXT
2007-2009 Chevrolet Avalanche, Silverado, Suburban, Tahoe
2007-2009 GMC Sierra, Yukon, Yukon Denali, Yukon XL, Yukon Denali XL
2008-2009 Hummer H2


This PI was superseded tp update model years and text. Please discard PIT4007C.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:

Some technicians may find that after SPS programming a replacement radio the display will show "LOCKED" or "THEFT LOCK". The radio theft deterrent system disables radio functionality if the VIN information sent by the BCM does not match the vehicle VIN information contained in the radio. The radio compares its learned VIN information to the VIN learned in the BCM via GMLAN. If a radio is replaced or swapped from another vehicle the radio will need to relearn the VIN information before it will function. The radio learns the VIN information during the SPS programming event.
Recommendation/Instructions:

Currently, some SPS programming events will NOT successfully learn the vehicles VIN information in the radio. Engineering is aware of this and working on a correction, however the following steps can be performed to resolve this condition if SPS programming does not unlock the radio:

Perform the radio setup in SI (Document ID# 1745049) as well as,
v
? F0: Diagnostics
? 2006
? Passenger Car
? (1) Chevrolet
? W
? WN Monte Carlo LTZ
? F6: Body and Accessories
? Entertainment
? F5: Module Setup
? F0: Radio
? F0: VIN Relearn
When prompted to erase the theft data: "select yes"
Shut the key off for 60 seconds and remove the Tech 2 from the vehicle.
After sixty seconds has elapsed, the VIN should relearn upon start up.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

- Interesting that they have you build the vehicle as a Monte Carlo even though that is not one of the affected platforms. Or could just be a misprint.

#PIT4583: Unable To Pragram (sic) BCM After A SPS Program Failure - keywords code communication diagnostics - (Feb 21, 2008)

Subject: Unable To Program BCM After A SPS Program Failure

Models: 2007-2008 Cadillac Escalade, EXT, ESV
2007-2008 Chevrolet Avalanche, Silverado, Suburban, Tahoe
2007-2008 GMC Sierra, Yukon, Yukon Denali, Yukon XL, Yukon Denali XL
2008 Hummer H2


The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:

You may notice that you are unable to program the BCM using the "Reprogram ECU" option on the Service Programming System (SPS). This failure to program typically happens after a programming event was interrupted due to a lack of communication between the vehicle and the TIS terminal or low vehicle voltage during programming.

When attempting to program the BCM after this incident the BCM may not complete the programming event.
Recommendation/Instructions:

If programming fails during the initial programming event, back out of the SPS application and re-select SPS from the TIS terminal application. When selecting the "programming process" choose "Replace and Program ECU", even though a new BCM is NOT being installed.

If the BCM still fails to reprogram try the following steps:

Turn the ignition key off and remove it from the ignition.
Open and close the driver door (turning retained accessory power off) and wait 30 seconds.
Perform SPS programming again using "Replace and Program ECU" as the programming process choice.

Note: If the BCM still fails to reprogram after following the above procedure, then turn the ignition key off and remove the BCM fuse and IS LPS fuse (located in the left IP fusebox) for 2 minutes. Reinstall the fuses and use "Replace and Program ECU" as the programming process choice.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.