P0A8E

DTC P0A8E

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 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.

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 for any open fuses.
2. Inspect all the 12-volt battery connections for proper torque as follows:

* At Battery
* At SGCM
* At Fuse block
Refer to Fastener Tightening Specifications.

3. If all connections were within torque specifications, replace the SGCM.

Repair Instructions

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