GM Service Manual Online
For 1990-2009 cars only

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 C2171: Low Tire Pressure Sensors Not Learned -- Main

Circuit/System Description

The tire pressure monitor (TPM) system has a radio frequency (RF) transmitting pressure sensor in each wheel/tire assembly. The module receives and translates the data contained in the tire pressure sensor RF transmissions into sensor presence, sensor mode, and tire pressure.

The receiver module receives a radio frequency (RF) transmission from each tire pressure sensor. Each sensor RF transmission contains its own unique identification (ID) code that must be learned into the module memory. Once all 4 IDs have been learned, the module continuously compares IDs received in transmission to its learned IDs to determine if all 4 sensors are present.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

Tire Pressure Sensor ID code is not learned.

Action Taken When the DTC Sets

The Tire Pressure Warning Light is illuminated.

Conditions for Clearing the DTC

A current DTC will clear when the Tire Pressure Control Module has undergone the sensor learn procedure.

Reference Information

Description and Operation

Tire Pressure Monitor 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

Verify that the Sensor ID's are learned.

If the ID's are not learned, program/setup the Tire Pressure Control Module. If the DTC resets, replace the Tire Pressure Control Module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Tire Pressure Sensor Learn
    •  Control Module References for Module replacement, setup, and programming