Tire Pressure Sensor Learn
Tire Pressure Sensor Learn
Learn Mode Description
The Tire Pressure Monitor (TPM) System uses the keyless entry transmitter, body control module (BCM), remote control door lock receiver (RCDLR), 4 radio frequency transmitting pressure sensors, and the serial data circuit to perform the TPM learn mode functions. The sensor learn procedure must be performed after every tire rotation, RCDLR replacement, or sensor replacement. Once the learn mode has been enabled, each of the sensors unique identification codes can be learned into the RCDLRs memory. When a sensor ID has been learned, the RCDLR sends a serial data message to the BCM to sound a horn chirp. This verifies the sensor has transmitted its ID and the RCDLR has received and learned it. The RCDLR must learn the sensor IDs in the proper sequence 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.
Sensor Functions Using J-46079
Each sensor has an internal low frequency coil. When the J-46079 Tire Pressure Monitor Diagnostic Tool is used in activate mode, it produces a low frequency transmission that activates the sensor. The sensor responds to an low frequency activation by transmitting in learn mode. When the RCDLR receives a learn mode transmission while in TPM learn mode, it will assign that sensors ID to the location on the vehicle relative to the order in which it was learned.
Sensor Functions Using Pressure Increase/Decrease Method
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 8.3 kPa (1.2 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 in re-measure mode. When the RCDLR 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.
Learn Mode Cancellation
The learn mode will cancel if the ignition is cycled to OFF, if more than 2 minutes have passed and no sensor have been learned, or if more than 5 minutes has passed for the entire procedure. If the learn mode is canceled before any IDs are learned, the RCDLR will remember all previously stored IDs and their locations. As soon as the RCDLR learns the first ID, all other IDs are erased from the RCDLRs memory.
TPM Learn Procedure
Important: Before proceeding with the steps below, ensure that no other learn procedure is being performed simultaneously or that no tire pressures are being adjusted on another TPM equipped vehicle within close proximity. Stray signals from other TPM equipped vehicles just driving by can be inadvertently learned. Performing the TPM Learn Procedure away from other vehicles will be necessary. In the event a particular sensor's information is displayed on the special tool upon activation but the horn does not chirp, it may be necessary to rotate the wheel valve stem to a different position due to the RF signal is being blocked by another component.
1. Place the ignition switch in the proper position as follows:
* With standard ignition switch, place the switch in the RUN position.
* With electronic keyless ignition, place the switch in the ACCY position
2. Initiate the TPM Learn Mode using one of the following procedures:
* Using a scan tool, initiate the TPM Learn Mode. A horn chirp will sound indicating the Learn Mode has been enabled.
* Simultaneously press the keyless entry transmitters lock and unlock buttons until a horn chirp sounds indicating the Learn Mode has been enabled.
3. Starting with the left front tire, learn the tire pressure using one of the following methods:
* Hold the antenna of the J-46079 aimed upward against the tire sidewall close to the wheel rim at the valve stem location. Press and release the activate button and wait for a horn chirp.
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.
* Increase/decrease the tire pressure for 8-10 seconds then wait for a horn chirp. The horn chirp may occur before or up to 30 seconds after the 8-10 second pressure increase/decrease time period has been reached.
4. After the horn chirp has sounded, repeat step 3 for the remaining 3 sensors in the following order:
* Right front
* Right rear
* Left rear
5. After the LR sensor has been learned, a double horn chirp will sound indicating all sensors have been learned.
6. Turn OFF the ignition to exit the learn mode.
7. After the learn mode has been exited, adjust all tires to the recommended pressures. Refer to Vehicle Certification, Tire Placard, Anti-Theft, and Service Parts ID Label.