GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

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

DTC Descriptor

DTC C0774:  Low Tire Pressure System Performance

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Low Tire Pressure System Performance

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C0774

Circuit Description

The tire pressure monitor (TPM) system has 4 radio frequency (RF) transmitting pressure sensors inside each wheel/tire assembly. If a sensor detects a low tire pressure, the DIC will display the CHECK TIRE PRESSURE, and the Electronic Brake Control Module (EBCM) will receive a serial data message that a DTC C0774 has set. The Vehicle Stability Enhancement System (VSES) will compensate for the low tire pressure with a calibration change to low tire present. Review the TPM for diagnostics for C0774.

Conditions for Running the DTC

Vehicle speed is 32 km/h (20 mph), or greater for 1 minute.

Conditions for Setting the DTC

    â€¢ The TPM detects a tire pressure difference in 1 tire of 8.2 kPa (1.2 psi) higher or lower than the other 3.
    â€¢ The EBCM will receive a serial data message that a DTC C0774 has set.

Actions Taken When the DTC Sets

    â€¢ A DTC C0774 is stored in memory.
    â€¢ The VSES system compensates for low tire pressure.

Conditions for Clearing the DTC

    â€¢ A current DTC will clear when the TPM system is reset.
    â€¢ A history DTC will clear after 100 consecutive malfunction-free ignition cycles from when the TPM system has been reset.

Diagnostic Aids

    â€¢ A possible cause of this DTC could be a low tire pressure in one of the four tires.
    â€¢ Review the tire pressure monitoring (TPM) system check for more information. Refer to Diagnostic System Check - Tire Pressure Monitoring .

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.