P0A8E

DTC P0A8E

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 Descriptor
DTC P0A8E
- 14 Volt Power Module System Voltage High

Circuit/System Description

The auxiliary power module (APM) 12-volt output voltage is used for a 12-volt line APM output voltage control and a 12-volt line voltage sensor rationality check.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

12-volt output voltage is greater than 18 volts for 2 seconds.

Action Taken When the DTC Sets

APM PWM off.

Conditions for Clearing the DTC

In both the hardware and software faults, normal range for 160 ms.

Diagnostic Aids

* Battery cable open (load dump)
* Fuse/relay box electrical failures

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

Warning

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.

Note: If a battery charger is connected to the vehicle, disconnect it now.

1. Inspect for any open fuses.
2. Inspect all the 12V battery connections for proper crimps and torque as follows:

* At Battery
* At SGCM
* At each Fuse block
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 and verify the DTC does not reset.

• 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