P0A7C

DTC P0A7C

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) 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°C (248°F) 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°C (248°F) for 3 seconds.


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



Reference Information
Schematic Reference

Hybrid Controls Schematics ()
Connector End View Reference

Component Connector End Views (Connector Views)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for Scan Tool Information


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.


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 (Verification Tests) after completing the diagnostic procedure.


Control Module References (Programming and Relearning) for SGCM replacement, setup, and programming