P1AA2

DTC P1A9E or P1AA2

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptors
DTC P1A9E
- Starter/Generator Inverter Phase U Overtemperature

DTC P1AA2
- Starter/Generator Inverter Phase V Overtemperature

Circuit/System Description

The power inverter module (PIM) temperature 1/2 sensor is used for overheat protection. The thermistor is located on the control board, near the phase U/V power MOSFET. The SGCM monitors the inverter temperature sensor for the following:

* To detect if the inverter phase U/V temperature sensor is shorted low.
* To detect if the inverter phase U/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

P1A9E, P1AA2

The engine is running.

Conditions for Setting the DTC

P1A9E, P1AA2

Temperature is greater than 175°C (347°F) for 20 ms.

Action Taken When the DTC Sets

P1A9E, P1AA2

Stop PWM (MGU shutdown)

Conditions for Clearing the DTC

P1A9E, P1AA2

Temperature is less than 150°C (302°F) for 2.5 seconds.

Diagnostic Aids

P1A9E, P1AA2

Possible cooling system failure due to the following:

* Restricted radiator air flow
* Restricted engine coolant flow
* Faulty thermostat
* Faulty engine water pump
* Inoperative SGCM water pump

Reference Information
Schematic Reference

Hybrid Controls Schematics (Hybrid Controls Schematics)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

Starter/Generator Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Testing

1. Inspect the 3 phase cable connections at the SGCM. Refer to Generator Control Module Replacement (Generator Control Module Replacement)
2. Verify that the 3 phase cables are torqued to within specifications. Refer to Fastener Tightening Specifications (Specifications)
3. With a scan tool, clear the DTC.
4. Ignition OFF, wait 30 seconds.
5. Ignition ON, operate the vehicle within the Conditions for Running the DTC.

• If the DTC resets, replace the SGCM.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

Control Module References (Programming and Relearning) for SGCM replacement, setup, and programming