Low Tyre Pressure Indicator Malfunction
Diagnostic Instructions
Circuit/System Description
The tyre pressure monitor sensor, one in each wheel/tyre assembly, sends sensor ID and tyre pressure via radio frequency communication. The Remote Function Actuator receives and translates the data contained in each sensors transmission and sends sensor ID and tyre pressure data via the serial data communication link to body control module (BCM). The BCM holds the tyre pressure application, calculates whether the tyre pressure is OK or not, sets fault codes and sends data messages to driver information centre and instrument cluster via serial communication data link requesting the appropriate tyre pressure monitor indicator illumination and also to display the appropriate data message.
Diagnostic Aids
| • | If unsure about the condition, cycle the ignition and observe the tire pressure monitor indicator icon. If the tire pressure monitor indicator icon is continuously illuminated after the instrument cluster bulb check is completed, a low tire pressure condition is present. Check the tires for damage or leaks and inflate to the tire placard specifications. Refer to Vehicle Certification, Tyre Placard, Anti-Theft, and Service Parts ID Label . If the tyre pressure monitor indicator icon flashes for 1 min (60-90 s) after the instrument cluster bulb check is completed and then remains illuminated, a tyre pressure monitor system DTC is set. Perform the Diagnostic System Check - Vehicle to proceed with the proper diagnosis. |
| • | Temperature can greatly affect tyre pressures. Low tyre pressure on a cold morning may cause the tyre pressure monitor indicator icon to turn ON. The air pressure in the tyre increases as the ambient temperature rises or as the tyre warms up while the vehicle is driven. The pressure may increase enough to exceed the predetermined low pressure threshold which will turn OFF the tyre pressure monitor indicator icon. |
| • | Some aftermarket wheel valve stem holes are located further from the wheel rim than original equipment wheels. When using the tyre pressure special tool to activate a sensor, ensure the tool aerial is no further than 15 cm (6 in) from the sensor and is aiming upward. |
| • | Aftermarket wheel value stem locations can cause a sensor to not function correctly. |
| • | A sensor may have been damaged due to a previous wheel/tire service or flat tire event. |
| • | 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. |
| • | Occasionally sensor transmissions are not received by the remote function actuator due to vehicle level radio frequency interference from items such as but not limited to aftermarket ignition systems, DVD players, CB radios, or metallic type window tinting. |
| • | 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 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 radio frequency signal is being blocked by another component. |
| • | Occasionally sensors can become dislocated due to previous tyre rotations where the sensor learn procedure was not performed or stray sensor transmissions have been received from other vehicles. Always learn the sensors to ensure the DTC set is for that actual physical corner of the vehicle. Refer to Tire Pressure Indicator Sensor Learn . |
Reference Information
Schematic Reference
Remote Function Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Tyre Pressure Monitor Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References
Special Tools
EL 46079 Tyre Pressure Monitor Diagnostic Tool
For equivalent regional tools, refer to Special Tools .
Circuit/System Testing
Note: Low tyre pressure in one or more tyres is indicated by a continuously illuminated tyre pressure monitor indicator icon after the instrument cluster bulb check is completed. If equipped with a driver information centre, a check tyre pressure type message will also be displayed. It is not necessary to perform the Learn procedure for a low tyre condition.
When a tyre pressure monitor DTC is set, the tyre pressure monitor indicator icon will flash for around 1 min (60-90 s) after the instrument cluster bulb check is completed and then remains illuminated. If equipped with a driver information centre, a service tyre monitor type ("Service tyre monitor system") message will also be displayed.
- Verify all tyres are inflated to the proper pressure within +10% using a known accurate hand held tyre pressure gauge. Refer to Vehicle Certification, Tyre Placard, Anti-Theft, and Service Parts ID Label . Set the correct tyre pressure on cold ambient temperature (if possible) and do not set it when vehicle has just been moving a lot (hot tyres influence tyre pressure).
| ⇒ | If not within the specified range, adjust all tyre pressures to specification and drive the vehicle over 20 km/h (15 MPH) for more than 2 min (maximum 10 min cumulative driving). Verify the tyre pressure monitor indicator icon is OFF. |
- Using the EL 46079, activate each tyre pressure sensor and record each sensor tyre pressure reading. Check the tyre pressures with a known accurate hand held tyre pressure gauge. Verify that the pressure readings from the special tool do not differ more than 27.6 kPa (4 PSI) from the actual tyre pressure readings.
| ⇒ | If not within the specified range, replace the appropriate tyre pressure sensor. |
- Using a scan tool, enable the tyre pressure learn mode. Use the EL 46079 in simulate mode to learn 4 simulated sensor transmissions into the BCM. Observe tyre pressures in the scan tool data display. Verify the simulated tyre pressures do not differ more than +/-27.6 kPa (4 PSI) of the scan tool reading (compared with pressure values in driver information centre display).
| ⇒ | If not within the specified range, replace the K9 Body Control Module. |
- Using a scan tool, perform the instrument cluster control functions All Indicators ON and OFF. Verify the tyre pressure monitor indicator icon turns ON and OFF.
| ⇒ | If the tyre pressure monitor icon does not turn ON and OFF, replace the P16 Instrument Cluster. |
- Ignition ON, use the scan tool to setup the Tyre Type/Pressure Selection in the BCM Module Setup menu. Refer to the Vehicle Certification, Tyre Placard, Anti-Theft, and Service Parts ID Label . Drive the vehicle over 20 km/h (15 MPH) for more than 2 min (maximum 10 min cumulative driving). Verify the tyre pressure monitor indicator icon goes OFF.
| ⇒ | If the tyre pressure monitor indicator icon is ON, replace the K9 Body Control Module. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| © Copyright Chevrolet. All rights reserved |
| © Copyright Chevrolet. All rights reserved |
