Tire Pressure Sensor Relearn
Once the TPM learn mode has been enabled, each of the sensor unique identification (ID) codes can be learned into the EGM/LGM memory. When a sensor's ID has been learned, the EGM/LGM sends a serial data message to the BCM to sound a horn chirp. This verifies the sensor has transmitted its ID and the EGM/LGM has received and learned it. The EGM/LGM must learn the sensor IDs in the proper order to determine correct sensor location. The first learned ID is assigned to the left front location, the second to right front, the third to right rear, and the fourth to left rear.
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 EGM/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 EGM/LGM 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 EGM/LGM's memory. On models that display the individual tire pressure on DIC, updated tire pressures will not be displayed until EGM/LGM receives 2 more valid transmissions from each sensor. After performing the procedure below, always test drive the vehicle above 25 mph for at least 2 minutes before viewing tire pressures on DIC.
- 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 EGM/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, 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, turn ignition switch to OFF position. Adjust all tire pressures to specification.