P0A37
DTC P0A37
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 Descriptor
DTC P0A37
- Starter/Generator Temperature Sensor Performance
Diagnostic Fault Information
Circuit/System Description
The starter/generator control module (SGCM) monitors the performance of the motor generator temperature sensor to detect if it is within range of the other temperature sensors, by comparing it to other temperature sensors it controls.
Conditions for Running the DTC
The engine is running.
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
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. Verify DTCs P0A38 or P0A39 are not set.
• If P0A38 or P0A39 are set diagnose those first.
2. Ignition OFF, disconnect harness connectors from the SGCM. Refer to Generator Control Module Replacement (Generator Control Module Replacement)
3. Test for 120 - 125 kohms between the signal circuit SGCM X2 terminal 2 and the low reference circuit terminal 14.
• If within the specified range , replace the SGCM.
4. Disconnect the 7 pin X1 connector at the MGU. Refer to Generator with Starter Replacement (Service and Repair)
5. Test for infinite resistance between the SGCM X2 connector terminal 2 and ground.
• If less than the specified value, test the circuit for short to ground.
6. 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 circuit for an open/high resistance.
7. 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, test the circuit for an open/high resistance.
8. 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