2010 Cadillac Truck Escalade RWD V8-6.2L Page 1532
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
Control Module References (See: Testing and Inspection/Programming and Relearning) for PIM replacement, setup, and programming.
P1AF8
DTC P1AF8 or P1AFE
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P1AF8
- Drive Motor 1 Control Module Shutdown Performance
DTC P1AFE
- Drive Motor 2 Control Module Shutdown Performance
Circuit/System Description
The drive motor generator power inverter control module (PIM) contains two motor control modules (MCMs) and the hybrid powertrain control
module (HPCM). Each MCM operates its respective drive motor generator based upon HPCM commands. Each MCM controls the speed, direction
and output torque of its respective drive motor generator through the sequencing actuation of high current switching transistors called insulated gate
bipolar transistors (IGBTs). Each drive motor generator operates utilizing 3 phase alternating current (ac) electricity. Each IGBT operates a single
phase of the drive motor generator. Each phase is individually identified as U, V and W. Each MCM monitors the current of each phase in order to
detect PIM overcurrent conditions.
At ignition ON, each MCM tests the integrity of the drive motor phase circuits by sequencing the IGBTs between open and shorted states while
simultaneously injecting a large amount of current into the phase circuits. The individual phase current sensors should all indicate similar current
flow and the current flow should increase and decrease at known rates based upon the inductance of the drive motor.
Conditions for Running the DTC
* The ignition is transitioned to ON.
* Ignition voltage is 8-18 volts.
* High voltage has been enabled.
Conditions for Setting the DTC
The control module has detected a phase current that indicates an open or shorted 3 phase circuit condition exists.
Action Taken When the DTC Sets
* DTCs P1AF8 and P1AFE are Type A DTCs.
* The HPCM commands the battery energy control module (BECM) to open the high voltage contactor relays.
Conditions for Clearing the DTC
DTCs P1AF8 and P1AFE are Type A DTCs.
Diagnostic Aids
* An intermittent loss of battery power to the drive motor generator power inverter control module (PIM) may set this DTC.
* An open or shorted 3 phase circuit, prior to ignition ON, may set this DTC.
Reference Information
Schematic Reference
Hybrid Controls Schematics ()
