PIT4811B: Hybrid No Crank With Multiple Diagnostic Codes – 2008-2013 Cadillac Chevrolet GMC

#PIT4811B: Hybrid No Crank With Multiple Diagnostic Codes – (Mar 8, 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This PI was superseded to update model year to 2013.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.



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.



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.


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