Diagnosing The Low Tire Pressure Warning Lamp

DIAGNOSING THE LOW TIRE PRESSURE WARNING LAMP





The Low Tire Pressure warning lamp is used to alert the driver that there is a problem in the TPM system. The following conditions can cause the lamp to come on:

- LOW TIRE PRESSURE
- STOP AND GO DRIVING
- TPM SYSTEM FAULT (DTC)

LOW TIRE PRESSURE

If the TPM module determines that the tire pressure being transmitted is below the low pressure threshold, the low tire pressure indicator lamp circuit is grounded and the TPM module turns on the "Low Tire" pressure indicator lamp.

1. Check all tires for proper tire pressure.
2. Adjust tire air pressure as necessary (refer to tire placard).
3. Connect the scan tool and verify tire pressures.

STOP AND GO DRIVING

Under certain driving conditions, the sensors will go into a "sleep" mode and stop regular transmissions. This interruption in signals will cause the TPM module to turn on the light. The light will be illuminated until the vehicle starts moving at a regular speed again. At that point, the light will go out, and the TPM will resume normal operation.

1. Connect the scan tool to the vehicle.
2. Drive the vehicle at 40 km/h (25 MPH) for at least 2 minutes.
3. Using the scan tool and an available assistant, monitor the Tire Pressure Sensors/Transmitters and verify the operation of all four Tire Sensors.

TPM SYSTEM FAULT (DTC)

The TPM module monitors, and will set DTCs for several system failures that may occur. The low tire pressure warning lamp will be lit, and stay on steady when the TPM module sets a DTC.

1. Using the scan tool, read the Current DTCs.
2. Refer to the TPM Diagnostics for the proper diagnostic test based on the Current DTCs.