P0A4C

DTC P0A4C

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 Descriptor

DTC P0A4C
- Starter/Generator Position Sensor Performance

Circuit/System Description

The motor generator unit (MGU) monitors to detect a fault in the angle data read by the motor generator position sensor circuit.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

(Data error) R/D IC angle data does not match with micro computer angle data. Self check fault when initial sequence (initialization error).

Action Taken When the DTC Sets

Stop PWM (MGU shutdown)

Conditions for Clearing the DTC

Clears 30 seconds after cycle wakeup signal.

Diagnostic Aids

Possible electrical failure at RD circuit

Circuit/System Testing

Caution: To help avoid personal injury, additional precautions must be taken prior to working on the generator control module or the generator starter. After removing the 36V battery cables from the generator battery, remove both engine wiring harness connectors from the generator control module. Wait at least 5 minutes and then remove the generator control module cover. Verify voltage levels at all 36V, 12V, and 3-phase connections, are less than 3 volts using a DMM before proceeding.

1. Disconnect the MGU X2 and the SGCM X2 connectors.
2. Test the circuits in the SGCM to MGU Terminal Reference Table as indicated below. Also check these circuits for short to ground.

^ If any of the circuits are not within specification, repair the open/high resistance or short to ground.

3. Reconnect MGU connector X2.
4. Test the circuits in the MGU to SGCM Specification Table to ground as indicated below.

^ If all circuits test normal, replace the MGU.

5. Reconnect the MGU X2 connector and disconnect the SGCM X2 connector. Refer to Generator with Starter Replacement and Generator Control Module Replacement.
6. Test the circuits in the SGCM to MGU Specification Table as indicated below.

^ If any of the circuits are not within the specified range, replace the SGCM.














Repair Instructions

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

* Generator with Starter Replacement for MGU replacement