Tire Pressure Indicator Sensor Learn
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Tire Pressure Indicator Sensor Learn
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Special Tools
J-46079/EL-46079
Tire Pressure Monitor Diagnostic Tool
For equivalent regional tools, refer to
Special Tools
The tire pressure monitoring system (TPM) uses the instrument panel cluster (IPC), the body control module (BCM), 4 pressure sensors transmitting on radio frequency and the serial data circuit to execute the functions in TPM relearn mode. Sensor relearning must be executed after each tire change, BCM change or sensor change. When relearn mode has been enabled, the respective sensors' unique identification codes can be learned in the BCM memory. When a sensor ID has been learned, the BCM sounds a horn chirp indicating the sensor has transmitted its ID and the BCM has received and learned it. The BCM 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. The turn signals will individually illuminate indicating which location is to be learned in the proper sequence.
Sensor Functions Using J-46079, EL-46079, or Equivalent
Each sensor has an internal low frequency coil. When the TPM 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 BCM 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 Learn mode. When the BCM 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.
Relearn Mode Cancellation
The Relearn mode will cancel if the ignition is cycled to OFF or if more than 2 minutes has elapsed for any sensor that has not been learned. If relearn mode is disabled before the first sensor has been learned, the original sensor ID codes are retained. If relearn mode is disabled after the first sensor has been learned, the following happens:
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All stored sensor IDs will be invalidated in the BCM memory.
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If equipped, the DIC will display dashes instead of tire pressures.
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These conditions will now require the relearn procedure to be repeated for the system to function properly.
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Note
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If using the scan tool to enable the relearn mode, the TPM tool must be used to activate the sensors. When this preferred method is used, any stray sensor signals will not affect the relearn procedure. 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 sensor signal is being blocked by another component.
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If using the DIC buttons to enable the relearn mode, the TPM tool or Pressure Increase/Decrease Method may be used. Before proceeding with this method, ensure that no other learn procedure is being performed simultaneously or that tire pressures are not being adjusted on another TPM equipped vehicle within close proximity. Stray signals from other TPM equipped vehicles just driving by can be inadvertently learned. If audible signals are heard at random from the car while learning is taking place, a foreign sensor has probably been learned and the procedure needs to be disabled and repeated. In this case, it is best to execute the TPM relearning procedure at a distance from other cars. In the event a particular sensor activation does not cause the horn to chirp, it may be necessary to rotate the wheel valve stem to a different position due to the sensor signal is being blocked by another component.
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Preferred Scan Tool Relearn Enable Method
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1.
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Apply park brake (manual transmission only).
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2.
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Ignition ON, using a scan tool, initiate the Tire Pressure Sensors Learn mode. A double horn chirp will sound indicating the Relearn mode has been enabled. The left front turn signal will also be illuminated.
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3.
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Starting with the left front tire, active the sensor by holding the antenna of the TPM tool 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. Once the horn chirp has sounded, the sensor information is learned and the turn signal in the next location to be learned will illuminate.
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After the horn chirp has sounded and the right front turn signal is illuminated, repeat step 2 for the remaining 3 sensors in the following order:
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When the left rear sensor has been learned and a double horn chirp has sounded, the learn process is complete and the BCM exits the Relearn mode.
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Alternate DIC Relearn Enable Method
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Apply park brake (manual transmission only).
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2.
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Ignition ON, activate the Relearn mode with the driver information center (DIC) display controls. A double horn chirp sounds indicating the Relearn mode has been enabled and the left front turn signal will also be illuminated.
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3.
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Starting with the left front tire, activate the tire pressure sensor by using one of the following methods:
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Hold the antenna of the TPM tool 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. Once the horn chirp has sounded, the sensor information is learned and the turn signal in the next location to be learned will illuminate.
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Warning
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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.
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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. Once the horn chirp has sounded, the sensor information is learned and the turn signal in the next location to be learned will illuminate.
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4.
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After the horn chirp has sounded and the right front turn signal is illuminated, repeat step 3 for the remaining 3 sensors in the following order:
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5.
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When the left rear sensor has been learned and a double horn chirp has sounded, the learn process is complete and the BCM exits the Relearn mode.
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