Low Tire Pressure Indicator Malfunction

Diagnostic Instructions Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Review Strategy Based Diagnosis for an overview of the diagnostic approach. Diagnostic Procedure Instructions provides an overview of each diagnostic category. Circuit/System Description For an overview of the component/system, refer to: Tire Pressure Monitor Description and Operation Diagnostic Aids If all 4 sensors fault DTC are set then look at DTC U0214 Lost Communication with Remote Function Actuator Module first prior to diagnosing TPM sensor DTCs. Some aftermarket wheel valve stem holes are located further away from the wheel rim than on original equipment wheels. When using the tire pressure monitor tool to activate a sensor, ensure the tool is placed along the tire sidewall close to the sensor and not on the rim. If a sensor is not recognized, it may help to rotate the wheel so that the sensor is in a different position relative to the vehicle. A sensor may have been damaged by a previous wheel/tire service or flat tire event Occasionally sensor transmissions are not received by the control module due to radio interference from internal (aftermarket ignition systems, DVD players, CB radios, traffic video cameras, or metallic type window tinting) or external RF sources. Before a defective sensor is replaced, execute the learn procedure for all sensors to make sure the DTC was set for the correct position on the vehicle. The wheels may have been exchanged before without learning the new positions. Aftermarket wheel valve stem locations can cause a sensor to not function correctly. The use of tire sealants can obstruct the sensor pressure sensing port and cause inaccurate tire pressure readings. If this condition is verified, remove the sealer from the tire and replace the sensor. Refer to: Tire Pressure Indicator Sensor Replacement The sensor activation procedure may have to be repeated up to 3 times before determining a sensor is malfunctioning. In the event a particular sensor is not learned and the horn does not chirp, it may be necessary to rotate the wheel to a different position due to the RF signal being blocked by another component. Occasionally, sensors can become mislocated due to previous tire rotations where the sensor learn procedure was not performed. Always learn the sensors to ensure the DTC set is for that actual physical corner of the vehicle. Perform the following learn procedure: Tire Pressure Indicator Sensor Learn. Reference Information Scan Tool Reference Control Module References for scan tool information Circuit/System Verification

Note

Low tire pressure in one or more tires is indicated by a continuously illuminated tire pressure monitor indicator icon after the instrument cluster bulb check is completed. If equipped with a driver information center, a tire pressure low-add air message will also be displayed. When a tire pressure monitor DTC is set, the tire pressure monitor indicator icon will flash for approximately 1 min after the instrument cluster bulb check is completed and then remains illuminated. If equipped with a driver information center, a service tire monitor type message will also be displayed.

1. Adjust all tire pressures to the correct pressure. Refer to Vehicle Certification, Tire Placard, and Anti-Theft Label.
2. Drive the vehicle over 40 km/h (25 mph) for greater than 2 min.
3. Verify the low tire pressure indicator is OFF. ⇒ If the low tire pressure indicator is ON 3.1. Perform the Tire Pressure Indicator Sensor Learn. 3.2. Compare the tire pressure sensor values to a digital air gauge, if the difference of 10% is noticed then inspect for damage or contamination. ⇒ If damage or contamination is detected Replace the sensor and perform the Tire Pressure Indicator Sensor Learn. ⇓ If no damage or contamination is detected Replace the sensor and perform the Tire Pressure Indicator Sensor Learn. 3.3. Verify the Tire Type and Pressure selections are setup correctly with scan tool. Refer to the Vehicle Certification, Tire Placard, and Anti-Theft Label, Control Module References. ⇒ If the BCM Tire Type and Pressure selections are incorrect Input the proper placard values for the vehicle with the SPS then drive the vehicle over 40 km/h (25 mph) for greater than 2 min. Refer to the K9 Body Control Module Control Module References. ⇓ If the BCM Tire Type and Pressure selections are correct 3.4. Ignition ON / Vehicle In Service Mode 3.5. Verify the low tire pressure monitor indicator icon turns ON and OFF when turning the ignition key on. ⇒ If the low tire pressure monitor icon does not turn ON and OFF Replace the P16 Instrument Cluster. ⇓ If the low tire pressure monitor icon turns ON and OFF 3.6. All OK ⇓ If the tire pressure indicator is OFF
4. All OK Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. If the sensors are not able to learn, they will need to be replaced. Refer to: Tire Pressure Indicator Sensor Replacement Control Module References for control module replacement, programming, and setup.