PIT4811B

Bulletin No.: PIT4811B
Date: Mar-2016
Subject:
Hybrid No Crank With Multiple Diagnostic Codes
Models:
2009-2013 Cadillac Escalade
2008-2013 Chevrolet Tahoe Hybrid
2008-2013 GMC Yukon Hybrid
2009-2013 Chevrolet Silverado Hybrid
2009-2013 GMC Sierra Hybrid
with Two-Mode Hybrid System (RPO HP2)
This PI was superseded to update model year to 2013. Please discard PIT4811A.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern
You may experience a "No Crank” concern with multiple codes set in several different modules. After retrieving the codes and recording them down on paper,
you may wonder which codes you should start with first.
Recommendation/Instructions
When dealing with a "No Crank" concern, please use the following diagnostic approach in the order shown below:
1.
Address codes: P1AE2-P1AE4, P1B05, or P1B06 first, as they're related to the High Voltage System Interlock Circuit for the high voltage system. These
codes may be experienced after a service part has been installed due to the High Voltage disconnect not being fully seated, the drive motor generator
control module sight shield (PIM cover) not fully seated, or the 2 wire connector may be disconnected at the transmission 3-phase cable cover .
2.
Address any CURRENT loss of communication DTC's that create a "U code" related to the Powertrain expansion bus or the high speed LAN bus.
3.
Address any low voltage concerns that may be related to a low 12 volt battery.
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.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may
occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools,
safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that
your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
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