The starter/generator control module (SGCM) monitors to detect the failure of the auxiliary power module (APM) temperature sensor by comparing the average of the 2 power inverter module (PIM) sensors and subtracting the module temperature to detect a faulty sensor.

The engine is running.

APM temperature sensor is greater than 55°C (131°F) for 2 seconds.

APM 50 percent maximum current output

APM temperature returns to normal range for 10 seconds.

Possible internal failure of the temperature sensors

Schematic Reference

Hybrid Cooling Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Starter Generator Control Module Cooling System Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

1. Verify the SGCM coolant pump operates.
2. Ignition ON, command the scan tool SGCM coolant pump output control ON and OFF.

⇒	If the SGCM coolant pump does not operate refer to SGCM Coolant Pump Malfunction.

3. Ignition ON, observe the scan tool SGCM temperature sensor parameters.

⇒	If only the one temperature sensor reads high, replace the SGCM.

SGCM Coolant Pump Malfunction

1. Ignition OFF, disconnect the harness connector at the SGCM coolant pump.
2. Ignition ON, test for B+ between the B+ circuit terminal A and ground.

⇒	If less than the specified value, test the B+ circuit for a short to ground or an open/high resistance.

3. Ignition OFF, connect a test lamp between the B+ circuit terminal A and the control circuit terminal B.
4. Ignition ON, command the SGCM Coolant Pump Relay ON and OFF with a scan tool. The test lamp should turn On and OFF when commanded.

⇒	If the test lamp does not turn ON and OFF when commanded, test the control circuit for an open/high resistance. If the circuit tests normal, replace the SGCM.

5. If all circuits test normal, test or replace the SGCM coolant pump

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.