P1B03

DTC P1B03 or P1B04

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 P1B03
- Drive Motor 1 Position Sensor Loss of Tracking

DTC P1B04
- Drive Motor 2 Position Sensor Loss of Tracking

Circuit/System Description

The drive motor 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.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The MCM cannot track the motor position for 146 milliseconds.

Action Taken When the DTC Sets

* DTCs P1B03 and P1B04 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

DTCs P1B03 and P1B04 are Type A DTCs.

Diagnostic Aids

Insure the drive motor generator position sensor harness shield circuits are properly grounded to the drive motor generator power inverter module (PIM) assembly prior to testing.

Special Tools

DT 48493 Jumper Harness

Circuit/System Testing

1. Disconnect the transmission 24-way connector.
2. Connect the DT-48493 jumper harness to the transmission 24-way connector.
3. Test the circuits in the Position Sensor Specification table as indicated below. Also test these circuits for short to ground.

^ 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 drive motor generator position sensor.

4. Disconnect DT-48493 from the transmission 24-way connector.
5. Connect the DT-48493 jumper harness to the transmission 24-way connector at the vehicle harness.
6. Disconnect PIM connector X1.
7. Test the circuits in the PIM to Transmission Terminal Reference table as indicated below. Also test these circuits for short to ground and the shield circuit if 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, replace the drive motor generator power inverter module assembly (PIM).


















Repair Instructions

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

* Drive motor generator 1 position sensor. Refer to Drive Motor with Generator Assembly Removal - 1st Position.
* Drive motor generator 2 position sensor. Refer to Drive Motor with Generator Assembly Removal - 2nd Position.
* Automatic transmission wiring harness assembly. Refer to Transmission Control Wiring Harness Extension Harness Removal.