U1026

Diagnostic Chart:

Wiring Diagram:

Circuit Description

The PCM monitors the serial data (class II) circuit for communications from the Automatic Transfer Case (ATC) controller. If the ATC controller is not communicating with the PCM this DTC will set.

Conditions for Setting the DTC

No serial data (class II) from ATC controller to the PCM.

Action Taken When the DTC Sets

This DTC will not illuminate the Malfunction Indicator Lamp (MIL).

Conditions for Clearing the MIL/DTC

^ A History DTC will clear after 40 consecutive warm up cycles with no failures of any non-emissions related diagnostic test.

^ PCM battery voltage is interrupted.

^ Use of a scan tool.

Diagnostic Aids

This DTC will not set unless the PCM and ATC controllers have already establish communications first. This DTC will only diagnos an open or intermittent connection from the ATC controller to the splice.


Test Description

The number(s) below refer to the step number(s) on the Diagnostic Table.

1. In this step, the Powertrain OBD System Check is being performed.