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 P1A7C: Starter/Generator Control Module Temperature Sensor Circuit Low VoltageDTC P1A7D: Starter/Generator Control Module Temperature Sensor Circuit High Voltage
Circuit/System Description
The starter/generator control module (SGCM) monitors the temperature sensor circuit to detect shorted low or high failure.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
P1A7C
The internal temperature sensor output voltage less than 0.2 volt for 1 second.
P1A7D
The internal temperature sensor output voltage greater than 4.6 volts for 1 second.
Action Taken When the DTC Sets
P1A7C, P1A7D
| • | 50 percent maximum torque limit. |
| • | APM 50 percent maximum current output. |
Conditions for Clearing the DTC
P1A7C, P1A7D
Return to normal range for 10 seconds.
Diagnostic Aids
P1A7C
Possible internal sensor short to ground or open.
P1A7D
Possible internal short to voltage or open.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Starter/Generator Description and Operation
Electrical Information Reference
| • | Circuit Testing |
| • | Wiring Repairs |
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Verify the SGCM coolant pump operates.
- Ignition ON, command the scan tool SGCM coolant pump output control ON and OFF.
- With a scan tool, clear the DTC.
- Ignition OFF, wait 30 seconds.
- Ignition ON, operate the vehicle within the Conditions for Running the DTC.
| ⇒ | If the SGCM coolant pump does not operate refer to SGCM Coolant Pump Malfunction. |
| ⇒ | If the DTC resets, replace the SGCM. |
Circuit/System Testing
SGCM Coolant Pump Malfunction
- Ignition OFF, disconnect the harness connector at the SGCM coolant pump.
- Ignition ON, test for B+ between the B+ circuit terminal A and ground.
- Ignition OFF, connect a test lamp between the B+ circuit terminal A and the control circuit terminal B.
- Ignition ON, command the SGCM Coolant Pump Relay ON and OFF with a scan tool. The test lamp should turn On and OFF when commanded.
- If all circuits test normal, test or replace the SGCM coolant pump
| ⇒ | If less than the specified value, test the B+ circuit for a short to ground or an open/high resistance. |
| ⇒ | If the test lamp does not turn ON and OFF when commanded, test the control circuit for an open/high resistance. If the circuit tests normal, replace the SGCM |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for SGCM replacement, setup, and programming |
