Tire Pressure Sensor Relearn

The TPM system uses the Body Control Module (BCM), headlight switch, 4 Radio Frequency (RF) transmitting pressure sensors, and the serial data circuit to perform the sensor learn mode functions. The sensor learn procedure must be performed any time the BCM is replaced, a sensor is replaced, or after the vehicle's tires have been rotated. Once the learn mode has been enabled, each of the sensor's unique Identification (ID) codes can be learned into the BCM's memory. When a sensor's ID has been learned, the BCM sends a serial data message to the BCM to sound a horn chirp. This verifies the sensor has transmitted its ID, and the BCM has received and learned it.

Each sensor takes a pressure measurement sample once every 30 seconds while in stationary mode. If the tire pressure increases, or decreases by more than 1.6 psi (11 kPa) from the last pressure measurement, another measurement will occur immediately to verify the change in pressure. If a pressure change has indeed occurred, the sensor transmits in re-measure mode. When the BCM receives a re-measure mode transmission while in learn mode, it will assign that sensor ID to the location on the vehicle relative to the order in which it was learned. The BCM must learn the sensor ID codes in the proper sequence in order to determine sensor location. The first learned ID is assigned to left front, the second to right front, the third to right rear and fourth to left rear.

The TPM system will cancel the learn mode if more than 2 minutes have passed and no sensors have been learned, or if the system has been in learn mode for more than 5 minutes. If the learn mode is canceled before any sensor has been learned, the BCM will remember all current sensor IDs and their locations. As soon as the first sensor ID code is learned, all other IDs are erased from the BCM's memory.

NOTE: Before proceeding with the steps below, ensure that no other sensor learn procedure is being performed simultaneously, or that tire pressures are not being adjusted on a TPM equipped vehicle within close proximity.

NOTE: In the following procedure, a TPM Sensor Activation Tool (J-46079) may be used in place of increasing/decreasing pressures to enable sensor. To use, place activator antenna against the tire sidewall close to the wheel rim at the valve stem location, then press and release the ACTIVATE button.

NOTE: If TPM Sensor Activation Tool (J-46079) is used, and vehicle is having trouble entering relearn mode, check batteries in activation tool. Low batteries may allow some functions to work, but not allow vehicle to perform learn function. When the internal battery is fresh (fully charged), the indicator is "full" or all dark. When the battery is depleted, the indicator shows "empty" or all light.

Turn ignition switch to ON position, with engine off. Apply parking brake.
NOTE: If learn mode cannot be enabled, TPM system is not enabled in BCM. See appropriate manufacturer service information.
Turn headlight switch from OFF to parking lamps 4 times within 4 seconds. A double horn chirp will sound and the low tire pressure indicator will begin to flash to indicate the learn mode has been enabled (the low tire pressure indicator should continue flashing throughout the matching procedure, and "SERVICE TIRE MONITOR" message will be displayed on the DIC).
NOTE: If a horn chirp does not sound after 35 seconds for any of the 4 sensors, turn ignition switch to OFF position to exit the learn mode. Repeat procedure from step 1.
Starting with left front tire, increase or decrease the pressure for 8-10 seconds, or until a horn chirp sounds. Horn chirp may occur before the 8-10 second pressure increase/decrease time period has been reached, or up to 30 seconds after the 8-10 second pressure increase/decrease time period has been reached.
After horn chirp has sounded, proceed as in step 3 for the next 3 sensors in the following order: right front, right rear and left rear.
After left rear sensor has been learned, check to see if the low tire pressure indicator is still flashing. If it is, turn ignition switch to OFF position to exit relearn procedure. Adjust all tire pressures to specification. If the low tire pressure indicator is not flashing, repeat procedure from step 1.