Tire Pressure Sensor Relearn

NOTE: If this procedure is performed following replacement and reprogramming of the Liftgate Module (LGM), DIC may display a low tire pressure fault and all tire pressures read 0 psi. If this problem occurs, see appropriate manufacturer service information.

Once the TPM learn mode has been enabled, each of the sensor's unique identification (ID) codes can be learned into the LGM memory. When a sensor ID has been learned, the LGM sends a serial data message to the BCM to sound a horn chirp. This verifies the sensor has transmitted its ID and the LGM has received and learned it. The LGM must learn the sensor IDs in the proper order to determine correct sensor location.

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 LGM 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 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 LGM will remember all previously stored sensor IDs and their locations. As soon as the first sensor ID code is learned, all other IDs are erased from the LGM'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 LGM. 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.
Starting with Left Front tire, use TPM Sensor Activation Tool, or increase or decrease tire 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, repeat procedure for the next 3 sensors in the following order: Right Front, Right Rear, Left Rear.
After left rear sensor has been learned, a horn chirp will sound indicating all sensors have been learned. Adjust all tire pressures to specification.
Drive the vehicle 25 mph (40 km/h) or greater until the scan tool displays current tire pressures and verify that the TPMS indicator icon is OFF.