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 P1A9C: Starter/Generator Inverter Phase U Temperature Sensor Circuit Low VoltageDTC P1A9D: Starter/Generator Inverter Phase U Temperature Sensor Circuit High Voltage
DTC P1AA0: Starter/Generator Inverter Phase V Temperature Sensor Circuit Low Voltage
DTC P1AA1: Starter/Generator Inverter Phase V Temperature Sensor Circuit High Voltage
Circuit/System Description
The power inverter module (PIM) temperature 1 and 2 sensors are used for overheat protection. The thermistors are located on the control board, near the phase U or V power MOSFET. The starter/generator control module (SGCM) monitors the inverter temperature sensor for the following:
| • | To detect if the inverter phase U or V temperature sensor is shorted low. |
| • | To detect if the inverter phase U or V temperature sensor is shorted high. |
If one of the above conditions is detected, the SGCM will set the appropriate DTC.
Conditions for Running the DTC
P1A9C, P1A9D, P1AA0, P1AA1
The engine is running.
Conditions for Setting the DTC
P1A9C, P1AA0
Sensor output voltage is less than 0.2 volt for 1 second.
P1A9D, P1AA1
Sensor output voltage is greater than 4.6 volts for 1 second.
Action Taken When the DTC Sets
P1A9C, P1A9D, P1AA0, P1AA1
50 percent maximum torque limit.
Conditions for Clearing the DTC
P1A9C, P1A9D, P1AA0, P1AA1
Normal range for 10 seconds.
Diagnostic Aids
P1A9C, P1AA0
Possible temperature sensor short to ground.
P1A9D, P1AA1
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 Verification
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.
P1A9C, P1A9D, P1AA0, P1AA1
- If DTC is history, refer to Testing for Intermittent Conditions and Poor Connections .
- If DTC is current, replace the SGCM.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for SGCM replacement, setup, and programming.
