2010 Cadillac Truck Escalade ESV AWD V8-6.2L Page 1508
DTC P0C4E or P0C4F
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 P0C4E
- Drive Motor 1 Position Exceeded Learning Limit
DTC P0C4F
- Drive Motor 2 Position Exceeded Learning Limit
Circuit/System Description
The drive motor generator position sensor is monitored by the motor control module (MCM). The MCM monitors the angular position, speed and
direction of the drive motor generator based upon the signals of the resolver-type position sensor. The position sensor, or resolver, contains a drive
coil, two driven coils and an irregular shaped metallic rotor. The metallic rotor is mechanically attached to the shaft of the drive motor generator. At
ignition ON, the MCM outputs a 7 volt ac, 10 kHz excitation signal to the drive coil. The drive coil excitation signal creates a magnetic field
surrounding the two driven coils and the irregular shaped rotor. The MCM then monitors the two driven coil circuits for a return signal. The
position of the irregular shaped metallic rotor causes the magnetically-induced return signals of the driven coils to vary in size and shape. A
comparison of the two driven coil signals allows the MCM to determine the exact position, speed and direction of the drive motor generator.
Offset is the relationship between the position sensor and the drive motor generator output shaft. When the ignition turned OFF, the MCM attempts
to learn the offset of the drive motor position sensor.
Conditions for Running the DTC
* The ignition is cycled OFF.
* Drive motor generator speed is less than 20 RPM.
Conditions for Setting the DTC
The position sensor offset exceeds 25 degrees during the learning process.
Action Taken When the DTC Sets
* DTCs P0C4E and P0C4F are Type C DTCs.
* The MCM uses the last learned valid position sensor offset.
Conditions for Clearing the DTC
DTCs P0C4E and P0C4F are Type C DTCs.
Diagnostic Aids
* The drive motor generator position sensor circuits operate at very low current. Extreme care must be taken when probing terminals and
manipulating harnesses.
* The sensor circuit loops are twisted pair with each pair covered in a foil shield. The shield circuits outside of the transmission are grounded to
a stud on the drive motor generator power inverter module (PIM) assembly.
* Ensure the drive motor generator position sensor harness shield circuits are properly grounded prior to testing.
Reference Information
Schematic Reference
Hybrid Controls Schematics ()
Connector End View Reference
* Component Connector End Views (See: Diagrams/Connector Views)
* Inline Harness Connector End Views (See: Power and Ground Distribution/Multiple Junction Connector/Diagrams)
Electrical Information Reference
