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 C2126: Tire Pressure Sensor ID Not Received

Circuit/System Description

After all IDs are learned, DTC C2126 is set in the tire pressure control module and the tire pressure indicator blinks for 1 minute then comes on.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

Tire pressure control module does not receive radio waves for sensors whose IDs are stored in the module.

Action Taken When the DTC Sets

The Tire Pressure Warning Light is illuminated.

Conditions for Clearing the DTC

The tire pressure control module successfully receives radio waves from the sensors whose IDs are stored in the tire pressure control module.

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 Testing

  1. With the scan tool, verify tire pressure sensors ID and locations:
  2. 1.1. Rapidly reduce the tire pressure for each wheel at least 6 psi within 30 seconds. It may take up to 3 minutes for the display to change.
    1.2. Record the sensor ID and location.
    If any of the parameters listed above are not displayed for one sensor, verify the sensor ID and correct it as necessary. If sensor ID matches, replace the tire pressure sensor.
  3. Enable the TPM learn mode. Verify all 4 sensor locations, IDs, and tire pressures match what the scan tool displays.
  4. If the scan tool data does not display, replace the Tire Pressure Receiver Module. If scan tool data still does not display, 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 replacement, setup, and programming