P0C18

DTC P0C17 or P0C18

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC P0C17
- Drive Motor 1 Position Not Learned

DTC P0C18
- Drive Motor 2 Position Not Learned

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 5 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 coils signals allows the MCM to determine the exact angle, 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 is cycled to OFF, the MCM attempts to learn the offset of the drive motor position sensor. At ignition ON the MCM monitors the identification information broadcast by the transmission control module (TCM) in order to detect possible transmission replacement after the position sensor offset was last learned.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

* The MCM has learned the drive motor position sensor offset at least once.
* The TCM identification information does not match that stored during the previous ignition OFF.
OR
* The MCM has learned the drive motor position sensor offset at least once.
* The MCM has lost communication with the TCM and the stored identification information is invalid indicating the TCM has not been programmed.

Action Taken When the DTC Sets

* P0C17 and P0C18 are Type A DTCs.
* The hybrid powertrain control module (HPCM) commands the battery energy control module (BECM) to open the high voltage contactor relays.

Conditions for Clearing the DTC

P0C17 and P0C18 are Type A DTCs.

Circuit/System Testing

1. Program the transmission control module as necessary.
2. Ignition OFF, wait 2 minutes.
3. Ignition ON, monitor DTC Status. DTC P0C17 and P0C18 should have passed last test.

^ If the DTC has passed, clear DTC Information. No further diagnosis is necessary.
^ If the DTC has failed, replace the drive motor generator power inverter module (PIM) assembly.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests