H2 V8-6.2L (2008)
Low Tire Pressure Indicator: Service and Repair
Tire Pressure Sensor Learn
Special Tools
J-46079 Tire Pressure Monitor Diagnostic Tool
Learn Mode Description
The Tire Pressure Monitor (TPM) System uses the instrument panel cluster (IPC), body control module (BCM), remote control door lock receiver
(RCDLR), keyless entry transmitter, 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 RCDLR 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. The turn signals will individually illuminate indicating which location
is to be learned in the proper sequence.
Sensor Functions Using J-46079
Each sensor has an internal low frequency coil. When the J-46079 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 sensor 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 RCDLR receives a Learn 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.
Learn Mode Cancellation
The learn 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 the learn
mode is cancelled before the first sensor is learned, the original sensor IDs will be maintained. If the learn mode is canceled after the first sensor is
learned, the following will occur:
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All stored sensor IDs will be invalidated in the RCDLR memory.
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If equipped, the DIC will display dashes instead of tire pressures.
*
DTC C0775 will be set.
These conditions will now require the learn procedure to be repeated for the system to function properly.
TPM Learn Procedure
Important: Before proceeding, 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 any random horn chirps are heard from the vehicle while performing the learn procedure, most likely a stray sensor
has been learned and the procedure will need to be cancelled and repeated. Under these circumstances, performing the TPM Learn Procedure
away from other vehicles would be highly recommended. In the event a particular sensor pressure increase/decrease 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.
1. Place the ignition switch in the proper position as follows:
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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:
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Using a scan tool, initiate the TPM Learn Mode. A double horn chirp will sound indicating the Learn Mode has been enabled. The left front
turn signal will also be illuminated.
*
On vehicles equipped with keyless entry, simultaneously press the keyless entry transmitters lock and unlock buttons until a double horn chirp
sounds indicating the Learn Mode has been enabled. The left front turn signal will also be illuminated.
