P0A7C

DTC P0A7C

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 P0A7C
- Starter/Generator Control Module Motor Electronics Overtemperature

Circuit/System Description

The starter/generator control module (SGCM) temperature sensor is used for system overheat protection. The SGCM monitors the board temperature sensor for an overtemperature condition.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

Board temperature is greater than 120 degrees Celsius (248 degrees Fahrenheit) for 1 second.

Action Taken When the DTC Sets

* Stop PWM (MGU shutdown).
* APM PWM off.

Conditions for Clearing the DTC

Board temperature is less than 120 degrees Celsius (248 degrees Fahrenheit) for 3 second.

Diagnostic Aids

Possible engine or SGCM cooling system failure due to the following:

* Restricted radiator air flow.
* Restricted engine coolant flow.
* Faulty thermostat.
* Faulty engine water pump.
* Inoperative SGCM coolant pump.

Circuit/System Verification

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. If DTC is history, refer to Testing for Intermittent Conditions and Poor Connections in Diagnostic Aids. Component Tests and General Diagnostics
2. With ignition ON, observe the scan tool SGCM temperature sensor parameters.

• If only the SGCM board temperature sensor reads high, replace the SGCM.

Repair Instructions

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

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