P1A9E

DTC P1A9E or P1AA2

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 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 MGU 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 ()
Connector End View Reference

Component Connector End Views (Connector Views)
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

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.


1. Inspect the 3 phase cable connections at the SGCM. Refer to Generator Control Module Replacement ().
2. Verify that the 3 phase cables are torqued to within specifications. Refer to Fastener Tightening Specifications ().

• If the 3 phase cables are within specifications, 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