P1A96

DTC P1A95 or P1A96

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 P1A95
- DC/DC Converter Stuck in 14-42 Volt Direction

DTC P1A96
- DC/DC Converter Stuck in 42-14 Volt Direction

Circuit/System Description

The starter/generator control module (SGCM) monitors to detect auxiliary power module (APM) fault when the APM is commanded in the normal charge mode causing an over current condition. If a fault is detected, the appropriate DTC will set.

Conditions for Running the DTC

P1A95, P1A96

The engine is running.

Conditions for Setting the DTC

P1A95

DC-DC direction indicates 42-14 direction, but converter stays in 14-42 direction and current is greater than 20 amps for 1 second.

P1A96

DC-DC direction indicates 14-42 direction, but converter stays in 42-14 direction and current is less than -20 amps for 1 second.

Action Taken When the DTC Sets

P1A95, P1A96
* Stop PWM (MGU shutdown)
* APM PWM off
* Battery disconnection (disconnect SW on/off)

Conditions for Clearing the DTC

P1A95, P1A96

Clears 30 seconds after cycle wakeup signal.

Diagnostic Aids

P1A95, P1A96

FET breakdown

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