Chevrolet Trax: DTC P162B: Remote vehicle speed limiting signal message counter incorrect

Diagnostic Instructions

• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P162B

Remote Vehicle Speed Limiting Signal Message Counter Incorrect

Circuit/System Description

When a remote slow-down request is sent from OnStar, the vehicle communication interface control module sends a serial data message to the engine control module (ECM) indicating that reduced vehicle speed has been requested. Once the request is active, the ECM begins reducing engine torque to match the requested vehicle speed and the REDUCED ENGINE POWER message is displayed.

Conditions for Running the DTC

• The engine run time is greater than 5 s
• A remote slow-down request is sent from OnStar

Conditions for Setting the DTC

• The VIN embedded in the slow-down request does not match the VIN stored in the ECM.
• The rolling code counter embedded in the slow-down request does not increment for ten consecutive messages.

Action Taken When the DTC Sets

• ECM ignores all reduced vehicle speed request messages from the vehicle communication interface module.
• The ECM stores DTC P162B in history.

Conditions for Clearing the DTC

• The condition responsible for setting the DTC no longer exists.
• A history DTC will clear after 40 malfunction-free ignition cycles have occurred.

Reference Information

Schematic Reference

OnStar/Telematics Schematics (Encore) , OnStar/Telematics Schematics (Trax)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

Description and Operation

Remote Vehicle Speed Limiting Description and Operation

Electrical Information Reference

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Perform the Stolen Vehicle Slow-Down Clear procedure with the scan tool.
2. Verify DTC P162B is not set.

• If DTC P162B is set

1. Replace the K73 Telematics Communication Interface Control Module.
2. Verify the DTC does not set while operating the vehicle within the Conditions for Running the DTC.

• If the DTC sets, replace the K20 Engine Control Module.
• If the DTC does not set

3. All OK.

• If DTC P162B is not set

3. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for telematics communication interface control module or engine control module replacement, programming, and setup

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