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P0C4F




DTC P0C4E or P0C4F

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 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 (Connector Views)
* Inline Harness Connector End Views (Diagrams)

Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Special Tools

DT-48493 Jumper Harness

Circuit/System Testing

Note: The drive motor generator position sensor circuits require proper circuit integrity for correct system operation. Just a few ohms of additional circuit resistance may cause position sensor signal degradation.

* Always inspect position sensor signal connectors for proper terminal contact.
* All diagnostic connections must be made with the approved test probes to prevent the creation of poor terminal contact.
* Connectors that contain position sensor signal circuits must always be clean and dry prior to mating. Foreign material or moisture within the connector may cause sensor signal degradation.

1. Ignition OFF, disconnect PIM X1 connector.
2. Using the Position Sensor Specification table specifications listed below, test the position sensor resistance at the PIM X1 circuits as indicated. Use the specifications for the drive motor generator that set the DTC. Also test each circuit for a short to ground.

• If any of the circuits are not within specification, continue with testing.
• If all circuits test normal, inspect for proper terminal contact at PIM X1 connector. If PIM X1 terminal contact tests OK, replace the applicable drive motor generator assembly.

3. Disconnect the transmission X176 24-way connector.
4. Connect the DT-48493 to the X176 24-way connector at the transmission.
5. Using the Position Sensor Specification table specifications listed below, test the position sensor resistance at the transmission X176 circuits as indicated. Use the specifications for the drive motor generator that set the DTC. Also test each circuit for a short to ground.

• If all circuits test normal, continue with testing.
• If any of the circuits are not within specification, test the internal transmission harness for the condition. If the internal transmission harness tests OK, replace the applicable drive motor generator.

6. Disconnect DT-48493 from the transmission X176 24-way connector.
7. Connect DT-48493 to the transmission X176 24-way connector at the vehicle harness.
8. Disconnect PIM X1 connector.
9. Using the PIM to Transmission Terminal Reference table listed below, test the vehicle harness continuity between PIM X1 connector and transmission X176. Also test these circuits for short to ground and to the shield circuit if the shield circuit is not presently grounded to the PIM assembly.

• If any of the circuits are not within the specified range, repair or replace the wiring harness.
• If all circuits test normal, inspect transmission connector X176 for proper terminal contact. If transmission connector X176 tests OK, inspect the harness for an intermittent concern.

















Repair Instructions

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

* Drive Motor with Generator Assembly Removal - 1st Position (8. Drive Motor with Generator Assembly Removal - 1st Position)
* Drive Motor with Generator Assembly Removal - 2nd Position (13. Drive Motor with Generator Assembly Removal - 2nd Position)
* Transmission Control Wiring Harness Extension Harness Removal (5. Transmission Control Wiring Harness Extension Harness Removal)

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