GM Service Manual Online
For 1990-2009 cars only

Learn Mode Description

The tire pressure monitor (TPM) system uses the keyless entry transmitter, instrument panel module (IPM), remote control door lock receiver (RCDLR), 4 radio frequency transmitting pressure sensor 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 tire pressure 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 sensors ID has been learned, the RCDLR sends a serial data message to the IPM to sound a horn chirp. This verifies the sensor has transmitted its ID code and the RCDLR has received and learned it. The RCDLR must learn the sensor IDs in the proper sequence to determine 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 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 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 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.

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 a 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.

Learn Mode Cancellation

The learn mode will cancel 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: If using the pressure increase/decrease method, the following procedure must be completed within 15 minutes from when the vehicle is stationary after being driven at 32 mph, or greater, for 10 seconds.

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.

  1. With the ignition switch, select the ACC mode.
  2. Simultaneously press the keyless entry transmitters lock and unlock buttons until a horn chirp sounds or use the scan tool and select Special Functions/Sensor Learn Mode Enable/Enable soft key. A horn chirp will sound indicating the mode has been enabled. When increasing tire pressure do not exceed the maximum inflation pressure as noted on the tire sidewall.
  3. 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 5-8 seconds then wait for a horn chirp. 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.
  4. After a horn chirp has sounded, proceed as in step 3 for the next 3 sensors in the following order:
  5. 4.1. Right Front
    4.2. Right Rear
    4.3. Left Rear
  6. After the LR sensor has been learned a double horn chirp will sound indicating all sensors have been learned.
  7. With the ignition switch, select the OFF mode to exit the learn mode.
  8. After the learn mode has been exited, adjust all tire pressures to the recommended pressure.