Return to Sorento

Sept. 10, 2009

SUBJECT VEHICLE: 2008 Kia Sorento.

SENSOR IN TIRE? No (sensors are located in each wheel well).

RESET PROCEDURE? Yes (whenever a new sensor is installed).

SPECIAL TOOLS NEEDED? Yes (TPMS exciter scan tool).

The tire pressure monitoring system for the 2008 Kia Sorento consists of a TPMS receiver, four radio frequency tire pressure sensors, four TPMS initiators, a low tire pressure warning indicator, a TPMS warning indicator and a wheel location indicator.

The sensors are located in each wheel well. Each sensor operates in four modes: configuration mode, normal delay auto mode, storage auto mode and alert mode.

In configuration mode, the sensor will measure pressure and temperature every four seconds and transmit the data every minute. In normal delay mode, the sensor will transmit for 12 minutes, then enter into storage mode. In storage mode, the sensor enters a low current consumption state where no measurements are made in order to conserve battery power. In alert mode, the sensor will measure pressure and transmit data every four seconds.

The TPMS receiver automatically locates and learns the TPMS sensor. The receiver sends a signal to the TPMS initiator, located in each wheel well, to wake up the TPMS sensors. The TPMS initiators are told to wake up the TPMS sensor every 10 minutes, to keep the TPMS sensor awake while the ignition switch is set to the ON position.

When tire pressure drops below the threshold, the low tire pressure indicator on the instrument cluster will be illuminated. If the system detects a fault or external fault with the TPMS receiver, initiator or sensor, the TPMS warning indicator on the cluster will be illuminated. If the fault is considered to be critical, the light will stay on throughout the entire ignition cycle.

Old out, new in

Before you can remove an old sensor and install a new one, you have to demount the tire from the wheel following the tire changer manufacturer instructions. Once you’ve accomplished this, you’re ready to remove the old sensor. Follow these steps:

1. Deflate the tire and remove the balance weights. Avoid tool contact with the valve during demounting.

2. Remove the sensor’s valve nut.

3. Discard the valve assembly.

Now you’re ready to install a replacement sensor:

1. Assemble the valve to the sensor and turn the valve three times with the square part of the screw in the slot.

2. Ensure the valve hole and mating face of the wheel are clean. Mount the assembly to the rim.

3. Tighten the washer and nut by hand until the valve thread meets the nut’s built-in, calibrated stop (see Figure 1).

4. Using a torque wrench, tighten the nut to between 35 and 35.7 in.-lbs. and lubricate the tire bead.

5. Start tire mounting about 15 centimeters from the valve. Move the mounting tool away from the valve.

6. Adjust the inflation pressure of all the wheels. Install the valve cap.

At this stage, you’re ready to initiate the replacement tire pressure sensor. Any time a sensor is replaced, the new one must be initiated.

Time to initiate

To initiate your new sensor, a TPMS exciter scan tool must be used. Do not perform the initiation procedure if the Sorento is parked on a metal floor or on an alignment rack or lift. Metal will transfer radio frequency signals, which will cause the procedure to fail.

1. Read each tire pressure sensor ID in the following order: front left, front right, rear left and rear right.

2. Connect the TPMS exciter to the Data Link Connector (DLC) located under the left side of the instrument panel.

3. Register the four sensor IDs to the receiver.

4. Disconnect the TPMS exciter from the diagnostic link. Cycle the ignition and wait three minutes. Make sure the “NORMAL RECEIVER STATE” message is now displayed.

5. Check to see that the TPMS system recognizes each tire.

6. Deflate the tire. Check to see that the low pressure indicator is illuminated.

7. If the indicators do not illuminate, turn the wheel one quarter and repeat step five. If the warning indicators come on, perform steps five and six on the rest of the tires. If each tire passes, you know that all four sensors have been initiated. If the warning indicators do not illuminate after this process, use the TPMS exciter to verify all four tire IDs have been registered.

Remember to not use puncture repair fluid when working with a TPMS system. Use of puncture repair fluid can block up the sensor pressure port, which will result in an incorrect warning.    ■

Information for this column comes from Mitchell 1’s ”Tire Pressure Monitoring Systems Guide” for domestic and import vehicles through 2008. 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.