For 1990-2009 cars only
Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC P0A38: Starter/Generator Temperature Sensor Circuit Low VoltageDTC P0A39: Starter/Generator Temperature Sensor Circuit High Voltage
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Signal | P0A38 | P0A39 | P0A39 | -- |
Low reference | -- | P0A39 | -- | -- |
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
Connector End View Reference
Description and Operation
Starter/Generator Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF, disconnect harness connectors from the SGCM. Refer to Generator Control Module Replacement.
- Test for 120-125 k ohms between the signal circuit SGCM X2 terminal 2 and the low reference circuit X2 terminal 14.
- Disconnect the connectors at the MGU. Refer to Generator with Starter Replacement.
- Test for less than 1 ohm between the SGCM X2 connector terminal 2 and the MGU X1 connector terminal G.
- Test for less than 1 ohm between SGCM X2 connector terminal 14 and the MGU X1 connector terminal F.
- If circuits test normal, replace the MGU.
| ⇒ | 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. |
| ⇒ | If greater than the specified value, test the signal circuit for an open/high resistance or short to voltage. |
| ⇒ | If greater than the specified value, repair the open/high resistance. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Generator with Starter Replacement for MGU replacement |
| • | Control Module References for SGCM replacement, setup, and programming |
