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 starter/generator control module (SGCM) connector C2.
2. Test the circuits in the SGCM to MGU Specification Table from the C2 connector to ground.

• If all of the circuits are within the minimum or maximum values specified, replace the SGCM.

3. Disconnect the MGU 10-pin connector.
4. Test the circuits in the SGCM to MGU Terminal Reference Table for an open, short to ground or high resistance.

• If all circuits test normal, replace the MGU.










Repair Instructions

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

Generator with Starter Replacement for MGU replacement.

Control Module References for SGCM replacement, setup, and programming.