Tire Pressure Monitoring System (TPMS) Indicator Illuminates Continuously

Tire Pressure Monitoring System

Principles of Operation

The Tire Pressure Monitoring System (TPMS) monitors the air pressure of all 4 road tires. The wheel-mounted tire pressure sensors transmit via radio frequency signals, to the Driver Door Module (DDM). TPMS functionality is integral to the DDM. These transmissions are sent approximately every 60 seconds when the vehicle speed exceeds 32 km/h (20 mph). The TPMS function compares each tire pressure sensor transmission against a low-pressure limit. If it has been determined that the tire pressure has fallen below this limit, the DDM communicates this on the vehicle communication bus to the instrument cluster. The instrument cluster then illuminates the TPMS indicator and displays the appropriate message(s) in the message center (if equipped).

For vehicles with different front and rear tire pressures (such as the E-Series and certain F-Series), the tire pressure sensors must be trained following a tire rotation. Failure to train the sensors will result in a false low tire pressure event, which will cause the TPMS indicator to illuminate.

For vehicles with the same tire pressures for front and rear tires, tire rotation will not affect the system.

Tire Pressure Monitoring System (TPMS) Indicator Illuminates Continuously

NOTE: A full-sized, matching spare wheel and tire, that is identical to the road wheel and tire, is available as an optional accessory. This spare wheel and tire is equipped with a tire pressure sensor but the sensor is not initially programmed to the Driver Door Module (DDM).

If this spare wheel and tire is in use on the vehicle, the sensor must be trained to the DDM and the remaining 3 sensors must be retrained to the DDM as well. If all 4 sensors are not trained to the DDM, the TPMS warning indicator will illuminate.

Make sure that all the wheels and tires installed on the vehicle are inflated to the correct pressure and trained to the DDM before attempting to diagnose a TPMS concern. Refer to Tire Pressure Monitoring System (TPMS) Sensor Training Programming and Relearning.

NOTE: If the spare tire is in use (including the optional full-sized, matching spare wheel and tire), the damaged road tire must be repaired and installed on the vehicle to restore complete TPMS functionality before carrying out any diagnosis.

NOTE: For vehicles with different front and rear tire pressures (such as F-Series and E-Series), the tire pressure sensors must be trained following a tire rotation. Failure to train the sensors will result in a false low tire pressure event, which will cause the TPMS indicator to illuminate.

For vehicles with the same tire pressures for front and rear tires, tire rotation will not affect the system.

1. The TPMS indicator remains on continuously for the following condition:
- Low Tire Pressure - The TPMS indicator is illuminated solid and the message center displays LOW TIRE PRESSURE (if equipped). This is displayed when any of the tire pressures are low. When this condition exists, the tire pressure must be adjusted to the recommended cold pressure as indicated on the VC label.

2. NOTE: The TPMS sensors do not transmit when the vehicle is stationary. If the vehicle has been stationary for more than 30 minutes, it will be necessary to wake up the sensors so they will transmit the latest tire pressure information to the DDM.

If the vehicle has been stationary for more than 30 minutes, activate the TPMS sensors. Refer to Tire Pressure Monitoring System (TPMS) Sensor Activation Programming and Relearning.