For 1990-2009 cars

The tire inflation monitoring (TIM) system alerts the driver of a large change in pressure in one tire. Whenever repairs are done on any of your tires, (inflate one or more, tire rotation, repair a flat, etc.) or whenever the battery is disconnected, perform the Tire Inflation Monitor Resetting . The system will then begin to learn the pressure at each tire throughout the operating speed range of the vehicle.

The system takes between 45 and 90 minutes to 'learn' the tire pressures, depending upon individual driving habits. Learning need not be accumulated during a single trip. Once learned, the system will remember until the RESET procedure is performed.

(1) | Electronic Brake Control Module (EBCM)
(2) | EBCM Mounting Bolt
(3) | Windshield Washer Reservoir Bracket
(4) | Windshield Washer Reservoir

The TIM system is a software driven system. The system uses the existing antilock brake system (ABS) components. The electronic brake control module (EBCM), wheel speed sensors, serial data line, and the instrument cluster perform the system functions.

The EBCM contains the software to perform the system monitoring functions. The EBCM uses wheel speed data obtained from the wheel speed sensors to detect relative pressure differences of 12 psi. This means that one tire is at least 12 psi lower in pressure than the other 3 tires. The EBCM uses only smooth data. Braking and acceleration or deceleration of greater than 0.1g, and/or any ABS system activity causes the EBCM to stop performing TIM system functions. When the EBCM detects a low tire pressure condition, the EBCM sends a message to the instrument cluster via the serial data line.

The instrument cluster displays the warning message LOW TIRE PRESSURE when commanded by the EBCM, via the serial data line.

(1) | Body Control Module (BCM)
(2) | BCM Wiring Harness Connectors
(3) | Heater Blower Motor

The serial data line is used to send all tire pressure monitor system related information between the EBCM, body control module (BCM), RESET switch, and the instrument cluster.

If the ABS is malfunctioning, the TIM system will be disabled.