P0C18

DTC P0C17 or P0C18

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions 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 position sensor is monitored by the motor control module. The motor control module 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 motor control module outputs a 7 V alternating current, 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 motor control module 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 motor control modules to determine the exact position, speed and direction of the drive motor generator.

The position sensor is part of the drive motor generator and is not serviced separately.

Offset is the relationship between the position sensor and the drive motor generator output shaft. Whenever the ignition is cycled to OFF, and the motor control modules attempts to learn the offset of the drive motor position sensor. The motor control modules will attempt to learn the position at hybrid wake-up, ignition ON only if no valid offset value has ever been learned. This condition would normally occur only after a motor control module reprogramming event.

Conditions for Running the DTC

Condition 1, 2, 3 and 4
* Hybrid wake-up signal is active.
* The motor control module has not previously learned a valid drive motor position sensor offset value.

Condition 2

Motor speed is less than 20 RPM.

Conditions for Setting the DTC

Condition 1

Position sensor offset value not learned because drive motor speed is greater than 50 RPM.

Condition 2

Position sensor offset value not learned because hybrid battery voltage is less than 192 V.

Condition 3

Position sensor offset value not learned because drive motor phase to phase current difference is less than 15 A.

Condition 4

Position sensor offset value not learned because offset learn value is greater than 25 degrees.

Action Taken When the DTC Sets

DTCs P0C17 and P0C18 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P0C17 and P0C18 are Type B DTCs.

Reference Information
Schematic Reference

Hybrid Controls Schematics Hybrid Controls Schematics
Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

1. Verify that DTCs P0A40, P0A45, P0A46, P0A78, P0A79, P0A3F, P0C05, P0C08, P0C0B, P0C0E, P0C4E, P0C4F, P0C52, P0C53, P0C57, P0C58, P0C61, P0C62, P0C5C, P0C5D, P1B03, P1B04 or P1B0D is not set.

• If DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.

2. If the DTC is set, program the T6 drive motor generator power inverter module. If the DTC resets, replace the T6 drive motor generator power inverter module.

Repair Instructions

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

Control Module References Control Module References for Drive Motor Generator Power Inverter Module replacement, setup and programming.