The auxiliary power module (APM) temperature sensor is used for overheat protection. The thermistor is located on the control board, near the phase APM power MOSFET. The starter/generator control module (SGCM) monitors the board temperature sensor for an APM overtemperature condition.

The engine is running.

APM temperature sensor is greater than 80°C (175°F) for 2 seconds.

APM PWM off

FET temperature for APM is less than 150°C (302°F) for 2.5 seconds.

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

Schematic Reference

Hybrid Controls Schematics

Connector End View Reference

Hybrid Controls Connector End Views

Electrical Information Reference

Scan Tool Reference

Scan Tool Data List

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. Inspect all 12 volt battery connections for a short to ground as follows:

•	At battery

•

At SGCM

•	At fuse block

2. If all connections are normal, replace the SGCM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for SGCM replacement, setup, and programming