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 Descriptor
DTC P0A37: Starter/Generator Temperature Sensor PerformanceCircuit/System Description
The starter/generator control module (SGCM) monitors the performance of the motor generator unit (MGU) temperature sensor to detect if it is within range of the other temperature sensors, by comparing it to other temperature sensors it monitors.
Conditions for Running the DTC
The engine is ON.
Conditions for Setting the DTC
Power inverter module (PIM) TEMP 1, PIM TEMP 2, auxiliary power module (APM) TEMP, Board TEMP, motor/generator unit (MGU) TEMP greater than 30°C (80°F) and engine OFF timer greater than 480 minutes of start up.
Action Taken When the DTC Sets
Hybrid system torque will be limited to 50 percent.
Conditions for Clearing the DTC
The MGU temperature sensor returns normal range for 10 seconds
Reference Information
Schematic Reference
Connector End View Reference
Hybrid Controls Connector End Views
Description and Operation
Starter/Generator Description and Operation
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.
- Verify DTCs P0A38 or P0A39 are not set.
- Ignition OFF, disconnect harness connectors from the SGCM. Refer to Generator Control Module Replacement
- Test for 120 - 125 kohms between C2 terminals 2 and 14.
- 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 the circuits test normal, replace the MGU.
| ⇒ | If P0A38 or P0A39 are set diagnose those first. |
| ⇒ | If within the 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.
| • | Generator with Starter Replacement for MGU replacement |
| • | Control Module References for SGCM replacement, setup, and programming |
