P1A7D

DTC P1A7C or P1A7D

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* 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 Voltage

DTC 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

Sensor output voltage less than 0.2 volt for 1 second.

P1A7D

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 sensor short to ground or open.

P1A7D

Possible short to voltage or open.

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.

If DTC is current, replace the SGCM.

Repair Instructions

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