An avalanche of service
SUBJECT VEHICLE: 2007-10 GM Avalanche.
SENSOR IN TIRE? Yes (located in each tire/wheel assembly).
RESET PROCEDURE? Yes (whenever a tire pressure sensor has been replaced).
SPECIAL TOOLS NEEDED? Yes (in certain cases, a TPM Sensor Activation Tool J-46079 may be used).
The 2007-10 Avalanche’s tire pressure monitoring system (TPMS) displays tire pressures and tire locations on the vehicle’s Driver Information Center (DIC), one of the system’s many components. Other components include a Powertrain Control Module, Instrument Panel Cluster, Remote Control Door Lock Receiver (RCDLR), a radio frequency transmitting pressure sensor in each tire/wheel assembly and a serial data circuit.
When the vehicle is stationary, the sensors go into stationary mode, in which they transmit once every 60 minutes. As the Avalanche’s speed increases to 20 mph, the sensors go into drive mode, in which they transmit once every 60 seconds.
When the TPMS detects a significantly under-inflated tire, a ‘CHECK TIRE PRESSURE” message displays on the DIC.
In order to service the Avalanche’s TPMS, you must first demount the tire from the wheel. Follow these steps:
1. Raise the vehicle on a suitable support. Remove the tire/wheel assembly from the vehicle.
2. Demount the tire from the wheel following the tire changer manufacturer’s instructions.
There are two kinds of sensors that can be used on the Avalanche’s TPMS: a clamp-in sensor and a snap-in sensor. To service the clamp-in sensor:
1. Remove the tire pressure sensor nut.
2. Remove the sensor from the wheel hole.
3. Remove the sensor grommet from the valve stem.
4. Clean any dirt or debris from the grommet sealing areas.
5. Insert the sensor in the wheel hole with the air passage facing away from the wheel.
6. Install the sensor nut. Position the sensor body parallel to the inside wheel surface.
7. Tighten the nut to 62 in.-lbs.
8. Install the tire on the wheel, and then install the assembly back on the vehicle.
Follow these steps to service the snap-in sensor:
1. Remove the TORX screw from the sensor and pull it straight off the pressure sensor valve stem (see Figure 1).
2. Remove the valve stem by pulling it through the rim.
3. Assemble the sensor to the valve stem and install the new TORX screw.
4. Apply tire soap to the rubber portion of the valve stem.
5. Pull the valve stem through in a direction parallel to the valve hole on the rim.
6. Install the tire on the wheel, and then install the assembly back onto the vehicle.
Now you’re ready to initiate the new sensor’s relearn process.
Time to learn
Before starting the relearn process, make sure that no other tire pressure sensor learn procedure is being performed simultaneously or that tire pressure levels are not being adjusted on a TPMS-equipped vehicle in close proximity.
There are three ways to enable the learn mode: using the TPM Sensor Activation Tool (J-46079); using keyless entry transmitters; and using the DIC. Here’s how to initiate and complete the learn process using the scan tool:
1. Using the tool, initiate the learn mode. A double horn chirp will sound indicating that the mode has been enabled. The left front turn signal also will be illuminated.
2. Starting with the left front tire, activate the sensor by holding the antenna of the tool upward against the 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 chirp has sounded, the information has been entered into the system. The turn signal in the next location to be learned will illuminate.
3. Repeat step 2 for the remaining three sensors in the following order: right front, right rear and left rear.
4. When the left rear sensor has been learned and the double horn chirp has sounded, the learn process is complete and the RCDLR will exit the learn mode.
5. Turn the ignition OFF and adjust all tire pressure levels to the recommended pressures.
Here’s how to initiate and complete the learn process using a keyless entry transmitter or the DIC:
1. Turn the ignition ON and initiate the learn mode. On models equipped with keyless entry, simultaneously press the keyless entry transmitter lock and unlock buttons until a double chirp sounds. This indicates that learn mode has been enabled. The left front turn signal also will be illuminated. Or, using the vehicle’s DIC, press and release the DIC INFO button until the TIRE LEARN message appears on the DIC display. Then press and hold the SET/RESET button until a double horn chirp sounds, indicating that learn mode has been enabled. The left front turn signal will be illuminated.
2. Starting with the left front tire, increase or decrease the tire pressure for eight to 10 seconds or until a horn chirp sounds. The chirp may occur before the tire pressure increase/decrease time period has been reached or up to 30 seconds after the increase/decrease period has been reached.
Once the chirp has sounded, the sensor information has been learned and the turn signal in the next location to be learned will illuminate.
3. After the horn chirp has sounded, proceed as in step two for the next three sensors in the following order: right front, right rear and left rear.
4. After the left rear sensor has been learned, a double horn chirp will sound. Turn the ignition switch to the OFF position to exit the learn mode.
5. Adjust all tires to specification.
Keep in mind that the TPMS will cancel the learn mode if more than two minutes have passed and no sensors have been learned, or if the system has been in learn mode for more than five minutes.
If the learn mode is canceled before any sensor has been learned, the RCDLR will remember all current sensor IDs and their locations.
Information for this column comes from Mitchell 1’s ”Tire Pressure Monitoring Systems Guide” for domestic and import vehicles through 2010. Headquartered in Poway, Calif., Mitchell 1 has provided quality repair information solutions to the automotive industry for more than 80 years. For more information, visit www.mitchell1.com.