Pinpoint Test Al: PSCM (Power Steering Control Module) DTC (Diagnostic Trouble Code) U0140:00

Refer to POWER STEERING CONTROLS for schematic and connector information.

Normal Operation and Fault Conditions

Description

Description
The PSCM monitors the HS-CAN messages when the voltage to the PSCM is greater than 9 volts and there are no Diagnostic Trouble Codes (DTCs) present inhibiting PSCM operation.

Pinpoint Test Applicability

Pinpoint Test Applicability
This test applies to PSCMDTC U0140 Lost Communication with the BCM only. It does not apply to any other module except the PSCM.

DTC Diagnostic Strategy

DTC Diagnostic Strategy
If the module DTC list results in a large number of Diagnostic Trouble Codes (DTCs), diagnose all module hard faults first (C102D, C1B00, C200B, C200C, C200D, U2011 and U3000) before diagnosing any network faults (lost communication or invalid data). If voltage concern Diagnostic Trouble Codes (DTCs) are present, diagnose those after any module hard faults and before any network faults. Diagnose all current and active Diagnostic Trouble Codes (DTCs) before diagnosing any historic Diagnostic Trouble Codes (DTCs).

Pinpoint Test Purpose

Pinpoint Test Purpose
To verify the PSCM wiring harness and connectors are OK. This test checks the connectors and wiring from the PSCM 3-pin connector at the steering column to the in-line connector in the passenger compartment. If these circuits are working correctly, the test then directs to check the BCM and wiring harness.

Diagnostic Aids

Diagnostic Aids
For additional information on the messages sent to the PSCM from the BCM module, refer to the Network Message Chart of the service information.
Do not install a new PSCM as part of the repair for a PSCMDTC U140:00.

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
PSCM U0140:00	Lost Communication With Body Control Module: No Sub Type Information	This DTC sets when communications between the PSCM and the BCM fails. DTC U0140:00 can also set due to a circuit failure on the HS-CAN, the PSCM wiring harness or a BCM concern

Possible Sources

Visual Inspection and Pre-checks

This DTC sets when the PSCM does not receive the ABS module messages within a certain time frame. This can occur if the ABS module wiring harness or electrical connectors are loose or damaged, or if the vehicle battery state of charge levels are low. Consult the DTC Index for additional information if needed.
Refer to Steering GSB for additional connector and wiring inspection tips.