P0A38

DTC P0A38 or P0A39

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptors
DTC P0A38
- Starter/Generator Temperature Sensor Circuit Low Voltage

DTC P0A39
- Starter/Generator Temperature Sensor Circuit High Voltage

Diagnostic Fault Information





Circuit/System Description

The starter/generator control module (SGCM) monitors to detect if the motor generator temperature sensor is shorted to ground, shorted to voltage or open.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

P0A38
* Sensor output voltage less than 0.2 V for 1 second.
* Temperature is greater than 215°C (419°F) for 1 second.

P0A39
* Sensor output voltage greater than 3.95 V for 1 second.
* Temperature is less than -20°C (-4°F) for 1 second.

Action Taken When the DTC Sets

P0A38, P0A39

Hybrid system torque will be limited to 50 percent

Conditions for Clearing the DTC

P0A38, P0A39

The MGU temperature sensor returns normal range for 10 seconds

Diagnostic Aids

P0A38

Possible internal temperature sensor signal circuit short to ground.

P0A39

Possible internal temperature sensor signal circuit short to voltage or open.

Reference Information
Schematic Reference

Hybrid Controls Schematics (Hybrid Controls Schematics)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

Starter/Generator Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Verification

Ignition ON, observe the scan tool Starter Generator Temperature parameter. The reading should be between -20°C (-4°F) and 100°C (212°F).

Circuit/System Testing

1. Ignition OFF, disconnect the X1 harness connector at the Starter Generator. Refer to Generator Control Module Replacement (Generator Control Module Replacement).
2. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 10 ohm between the low reference circuit terminal F and ground.

• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the SGCM.

3. Ignition ON, verify the scan tool Starter Generator Temperature parameter is less than -39°C (-38.2°F).

• If greater than the specified range, test the signal circuit terminal G for a short to ground. If the circuit tests normal, replace the SGCM.

4. Install a 3 A fused jumper wire between the signal circuit terminal G and the low reference circuit terminal F. Verify the scan tool Starter Generator Temperature parameter is greater than 100°C (212°F).

• If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the SGCM.

5. If all circuits test normal, test or replace the Starter Generator.

Repair Instructions

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

* Generator with Starter Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for SGCM replacement, programming and setup