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 C2177: Initialization Not Complete

Circuit/System Description

Initialization is required after replacing the tire pressure control module, tire pressure sensors, tire pressure, or rotating the tires.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

All of the following are met:

    • Tire pressure sensor is not in stop mode.
    • Tire pressure sensor signal is not received for 20 minutes or more.
    • Vehicle speed is more than 5 mph for 20 minutes or more.

Action Taken When the DTC Sets

The Tire Pressure Warning Light is illuminated.

Conditions for Clearing the DTC

Vehicle speed is greater than 12 mph for 3 seconds.

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 do not change or are not displayed for one sensor, replace the suspect tire pressure sensor.
  3. Disconnect the harness connector at the tire pressure control module.
  4. Disconnect the harness connector at the tire pressure receiver module.
  5. Test for less than 1 ohm between the 5-volt reference circuit terminal 6 and terminal 5.
  6. If greater than the specified value, test the 5-volt reference circuit for an open/high resistance.
  7. Test for less than 1 ohm between the signal circuit terminal 12 and terminal 1.
  8. If greater than the specified value, test the signal circuit for an open/high resistance.
  9. Test for less than 1 ohm between the ground circuit terminal 11 and terminal 4.
  10. If greater than the specified value, test the ground circuit for an open/high resistance.
  11. Test for infinite resistance between the 5-volt reference circuit terminal 6 and ground.
  12. If not the specified value, test the 5-volt reference circuit for a short to ground.
  13. Test for infinite resistance between the signal circuit terminal 12 and ground.
  14. If not the specified value, test the signal circuit for a short to ground.
  15. Enable the TPM learn mode. Verify all 4 sensor locations, IDs, and tire pressures match what the scan tool displays.
  16. If the scan tool data does not display, replace the tire pressure receiver module. If DTC sets again, 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