TPMS module diagnostics (Discovery 3)

Diagnostics

The TPMS module has a diagnostic connection via the medium speed CAN bus, which allows the system status and faults to be determined using T4.

In addition, the TPMS module's on-board diagnostic software continuously monitors the system and alerts the driver to system malfunctions by activating the yellow and red indicators, sounding the instrument cluster alarm, and/or displaying a message on the instrument cluster.

Troubleshooting

If the sensor is faulty, a yellow light will illuminate on the instrument cluster. In addition, the message 'XX Tyre Pressure Not Monitored' will be displayed on the message center display. (tire pressure XX not monitored).

If multiple sensors fail, the TPMS module registers a more serious fault and the yellow indicator lights up. In addition, the message 'Tyre Pressure Monitoring System Fault' is displayed in the message center. (tire pressure monitoring system malfunction). Radio frequency interference affecting the reception of signals by the system may also be the cause of this malfunction. When the interference is eliminated, the malfunction disappears automatically and the TPMS operates normally.

When the tire pressure sensor battery voltage is low, the sensor transmits a message to the TPMS module. The module stores the low battery voltage information as a fault condition and no visual warnings are given. When the battery fails, the sensor stops transmitting information and the TPMS module commands the message center display to display a message such as 'FL Tire Not Being Monitored' (air pressure in the left front tire is not controlled). The dealer must use T4 to determine the TPMS module fault condition to determine the cause of the message. If the battery is faulty, the sensor must be replaced and the stored faults must be cleared using T4. The TPMS module will learn the identity of the new sensor when the vehicle is driven. If the spare tire sensor is replaced (if available), its identification data must be manually programmed into the module using T4, or the wheel must be used as a "working" wheel for 15 minutes at speeds above 20 km/h, then removed and replaced in the spare wheel position.