P0A38

DTC P0A38 or P0A39

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 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 volt for 1 second.
* Temperature is greater than 215°C (419°F) for 1 second.

P0A39
* Sensor output voltage greater than 3.95 volts 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 (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Starter/Generator Description and Operation (Description and Operation)
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 Testing

1. Ignition OFF, disconnect harness connectors from the SGCM. Refer to Generator Control Module Replacement (Generator Control Module Replacement).
2. Test for 120-125 k ohms between the signal circuit SGCM X2 terminal 2 and the low reference circuit X2 terminal 14.

• If not within the specified range , test the signal circuit for short to ground or the signal circuit shorted to the low reference circuit.

• If the circuits test normal, replace the SGCM.

3. Disconnect the connectors at the MGU. Refer to Generator with Starter Replacement (Service and Repair).
4. Test for less than 1 ohm between the SGCM X2 connector terminal 2 and the MGU X1 connector terminal G.

• If greater than the specified value, test the signal circuit for an open/high resistance or short to voltage.

5. Test for less than 1 ohm between SGCM X2 connector terminal 14 and the MGU X1 connector terminal F.

• If greater than the specified value, repair the open/high resistance.

6. If circuits test normal, replace the MGU.

Repair Instructions

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

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