J-46079 Tire Pressure Monitor Diagnostic Tool

The tire pressure monitor (TPM) system uses the antenna module, dash integration module (DIM), keyless entry transmitter, 4 radio frequency (RF) transmitting pressure sensors, and the serial data circuit to perform the TPM learn mode functions. The sensor learn procedure must be performed any time the antenna module is replaced, a sensor is replaced, or after every tire rotation. Once the learn mode has been enabled, each of the sensor's unique identification (Id) codes can be learned into the antenna module's memory. When a sensor's Id has been learned, the antenna module sends a serial data message to the DIM to sound a horn chirp. This verifies the sensor has transmitted its Id and the antenna module has received and learned it. The antenna module must learn the sensor Ids in the proper order to determine correct sensor location. The first learned Id is assigned to left front, the second to right front, third to right rear and forth to left rear.

Each sensor takes a pressure measurement sample once every 20 seconds while in stationary mode. If the tire pressure increases, or decreases by more than 11 kPa (1.6 psi) 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 a re-measure mode transmission. When the antenna module receives a re-measure mode transmission while in TPM learn mode, it will assign that sensor's Id to the location on the vehicle relative to the order in which it was learned.

Each sensor has an internal low frequency (LF) coil. When the TPM tool is used in activate mode it produces an LF transmission that activates the sensor. The sensor responds to an LF activation by transmitting in learn mode. When the antenna module receives a learn mode transmission while in TPM learn mode, it will assign that sensor's Id to the location on the vehicle relative to the order in which it was learned.

The antenna module will cancel the learn mode if more then 2 minutes have passed and no sensors have been learned, or if it has been in learn mode for more than 5 minutes. If the learn mode is canceled before any Ids are learned, the antenna module will remember all previously stored Ids and their locations. As soon as the fist sensor Id is learned, all other Ids are erased from the antenna module's memory.

Important: Before proceeding with the steps below, ensure that no other sensor learn procedure is being performed simultaneously, or that no tire pressures are being adjusted on another TPM equipped vehicle within close proximity.

1. Turn ON the ignition, with the engine OFF.
2. Apply the parking brake.
3. Using the keyless entry transmitter, lock and unlock the vehicles doors 3 times in order to synchronize the transmitter with the antenna module.

Important: If the TPM learn mode cannot be enabled, ensure the TPM system is enabled in the DIM. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.

4. Simultaneously press the keyless entry transmitter's lock and unlock buttons, or with the scan tool select Special Functions/Sensor Learn Mode Enable/On soft key. A horn chirp will sound indicating the mode has been enabled.

Caution: Over inflating tires may cause personal injury or damage to the tires and wheels. When increasing tire pressure do not exceed the maximum inflation pressure as noted on the tire sidewall.

5. Starting with the left front tire, hold the antenna of the J-46079 TPM tool against the tire sidewall close to the wheel rim at the valve stem location then press and release the activate button and wait for a horn chirp, or increase/decrease the tire pressure for 5-8 seconds, or until a horn chirp sounds. The horn chirp may occur before the 5-8 second pressure increase/decrease time period has been reached, or up to 30 seconds after the 5-8 second pressure increase/decrease time period has been reached.
6. After the horn chirp has sounded, proceed as in step 5 for the next 3 sensors in the following order:

6.1.	Right front

6.2.	Right rear

6.3.

Left rear

7. After the left rear sensor has been learned, a double horn chirp will sound, indicating all 4 sensor Ids have been learned.
8. Turn OFF the ignition.
9. Adjust all tire pressures to the recommended kPa/psi. Refer to Tire Placard in General Information, or to Tire Inflation Pressure Specifications in Maintenance and Lubrication.