J-46079 Tire Pressure Monitor Diagnostic Tool.

The tire pressure monitor (TPM) system uses the passenger door module (PDM), body control module (BCM), exterior lamp switch, park brake switch, 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 after the PDM is replaced, a sensor is replaced, or a tire rotation. Once the TPM learn mode has been enabled, each of the sensors unique identification (Id) codes can be learned into the PDM's memory. When a sensor's Id has been learned, the PDM sends a serial data message to the BCM to sound a horn chirp. This verifies the sensor has transmitted it's Id and the PDM has received and learned it. The PDM must learn the sensors 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.

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 re-measure mode transmission. When the PDM receives a re-measure mode transmission while in TPM learn mode, it will assign that sensor 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 J-46079 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 PDM 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 PDM will cancel the learn mode if more then 2 minutes have passed and no sensors have been learned, or if the PDM has been in learn mode for more than 5 minutes. If the learn mode is canceled before any sensor has been learned, the PDM will remember all current sensor Ids and their locations. As soon as the fist sensor Id code is learned, all other Ids are erased from the PDM's memory.

Important: Before proceeding with the steps below, verify the following:

1. Turn ON the ignition, with the engine OFF.
2. Apply the parking brake.
3. Turn the exterior lamp 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 indicating the TPM learn 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.

Important: If a horn chirp does not sound after 35 seconds for any of the 4 sensors, turn the ignition OFF to exit the learn mode and repeat the procedure from step 1.

4. Starting with the left front tire, hold the antenna of the J-46079 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 8-10 seconds, or until a horn chirp sounds. The 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.
5. After the horn chirp has sounded, proceed as in step 4 for the next 3 sensors in the following order:

5.1.	Right front

5.2.	Right rear

5.3.

Left rear

6. After all sensors have been learned, exit the learn mode by turning OFF the ignition.
7. After the learn mode has been exited, adjust all tire pressures to the recommended kPa/psi. Refer to Vehicle Certification Label .