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
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
P0A39
Sensor output voltage greater than 3.95 volts for 1 second
Action Taken When the DTC Sets
P0A38, P0A39
50 percent maximum torque limit
Conditions for Clearing the DTC
P0A38, P0A39
Normal range for 10 seconds
Diagnostic Aids
P0A38
Possible temperature sensor short to ground.
P0A39
Possible temperature sensor short to voltage or open.
Reference Information
Schematic Reference
Connector End View Reference
Hybrid Controls Connector End Views
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
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.
- Disconnect harness connector C2 from the SGCM. Refer to Generator Control Module Replacement .
- Using the appropriate test adapters, test for 120 - 125 kohms resistance between terminals 2 and 14 at room temperature.
- Disconnect the 7 pin C1 connector at the MGU. Refer to Generator with Starter Replacement .
- Test for less than 1 ohm between SGCM connector harness terminal 2 and the MGU C1 connector harness terminal G.
- Test for less than 1 ohm between SGCM connector harness terminal 14 and the MGU C1 connector harness terminal F.
- If both circuits test normal, replace the MGU.
| ⇒ | If within specified range, replace the SGCM. |
| ⇒ | If greater than the specified value, repair the open/high resistance. |
| ⇒ | If greater than the specified value, repair the open/high resistance. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for SGCM replacement, setup and programming |
| • | Generator with Starter Replacement for MGU replacement |
