C0077
C0077- LOW TIRE PRESSURE
For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.
- When Monitored:
Continuously.
- Set Condition:
A low pressure condition will exist when the tire pressure falls below or is equal to the low pressure threshold value as specified for the vehicle.
1. DTC STATUS
NOTE: If the incorrect Placard Values were programmed into the WCM, a DTC could be set. Before continuing with any TPM diagnostic test, using the scan tool, check that the correct Placard Values have been programmed in to the module.
NOTE:
If the following conditions are present:
- Low Tire Pressure DTC
- Tire Pressure Monitoring (TPM) Sensor Internal DTC
- Spare Tire is not equipped with a Tire Pressure Monitoring (TPM) Sensor
- Spare Tire is currently on the vehicle
Repair the tire and place it back on the vehicle.
Test drive the vehicle.
If the DTCs reset continue with the diagnostic procedure.
1. Ignition on, engine not running.
2. With the scan tool, read DTCs.
Is the DTC status at this time?
Yes
- Go To 2
No
- Go To 5
2. LOW TIRE PRESSURE
NOTE: The DTC can be caused by many different factors and might not be a sensor/transmitter or a WCM) fault. Interference from other elements will over power the sensor/transmitter RF frequency making erratic operation to the TPM system. Check the vehicle for aftermarket accessories that could compromise the RF frequency signal before diagnosing the TPM system.
NOTE: Seasonal temperature changes will affect tire pressure, and may have caused the tire pressure to fall below the low pressure warning threshold. Tire pressure should always be set based on cold inflation tire pressure (placard). This is defined as the tire pressure after a vehicle has not been driven for more then 3 hours, and in outside ambient temperatures.
1. Correct all tire pressure to the recommended specifications and wait 2 minutes.
2. With the scan tool, clear DTCs in the Wireless Control Module (WCM).
3. Test Drive the vehicle for a minimum of 10 minutes with vehicle speed greater than 15 m.p.h. (24 km/h).
4. Use a TPM-RKE Analyzer 9936 to scan each tire pressure sensor, and make sure the Sensor IDs matches what is programmed into the WCM. The Sensor Identifications are located under "Data Display" for the "WCM Wireless Control Module". If the sensor IDs does not match, following the programming steps outlined in the diagnostic scan tool for "Program Tire Sensor ID w/TPM Tool" under "Miscellaneous Functions" for the "WCM/Wireless Control Module" menu item.
5. With the scan tool, read DTCs.
NOTE: When scanning a sensor with a TPM-RKE Analyzer 9936 , replace the TPM sensor if the results show a "Damaged Accel", "Damaged Temp", or "Damaged Press".
Does the DTC reset or is the status Active for this DTC?
Yes
- Go To 3
No
- Test Complete.
3. TIRE PRESSURE MONITORING (TPM) SENSOR
NOTE: Before continuing, ensure the tire is free from any leaks or damage that would cause a low tire pressure condition. If a problem is found, repair as necessary and retest.
1. With the scan tool, go under "Data Display" for the "WCM Wireless Control Module" and find the compensated tire pressure values. Located underneath each Sensor Identification locations. If any compensated tire pressure values are equal or lower then the Tire Low Pressure Threshold. The corresponding TPM sensor needs to be located and replaced.
NOTE: The following tests are used to locate the Tire Pressure Monitoring (TPM) Sensor/Transmitter that is setting the low pressure fault. If the tires have been rotated, the Tire Pressure Monitoring (TPM) Sensor/Transmitter are no longer in sequence from the factory. Faults are linked to the sensor/transmitter IDs. You MUST locate the correct Tire Pressure Monitoring (TPM) Sensor/Transmitter that set the fault before continuing. Use one or more of the following methods below.
2. METHOD 1: Use a TPM-RKE Analyzer 9936 to scan each tire pressure sensor. If a suspected sensor has been located, lower the tire pressure to 20 PSI, wait for two minutes, and check the scan tool for changes to any compensated tire pressure values.
3. If there was a pressure change to any compensated tire pressure values, check to make sure that the TPM-RKE Analyzer is set correctly, and repeat the process on each wheel on the vehicle until the faulty Sensor/Transmitter has been identified.
NOTE: When scanning a sensor with a TPM-RKE Analyzer 9936 , replace the TPM sensor if the results show a "Damaged Accel", "Damaged Temp", or "Damaged Press".
4. METHOD 2: Starting with the left front wheel, deflate the tire to 20 PSI, wait two minutes, and check the scan tool for changes to any compensated tire pressure values.
5. If there was a pressure change to any compensated tire pressure value, repeat this process on each wheel on the vehicle until the faulty Sensor/Transmitter has been identified.
Has the malfunctioning/faulty TPM sensor been located?
Yes
- Replace the Tire Pressure Monitoring (TPM) Sensor.
- Perform the TPM VERIFICATION TEST. Tire Pressure Monitor (TPM) Verification Test.
No
- Go To 4
4. WIRELESS CONTROL MODULE (WCM)
1. Replace the Wireless Control Module (WCM).Perform the WCM VERIFICATION TEST. Wireless Control Module (WCM) Verification Test.
2. With the scan tool, read DTCs.
3. Drive the vehicle for a minimum of 10 minutes while maintaining a continuous speed above 24 km/h (15 mph). During this time the system will learn the sensor IDs.
Are there any DTCs present?
Yes
- Repair not complete, perform the appropriate diagnostic procedure.
- Perform the TPM VERIFICATION TEST. Tire Pressure Monitor (TPM) Verification Test.
No
- Repair is complete.
5. INTERMITTENT TIRE PRESSURE MONITORING (TPM) SENSOR DTC
1. The conditions necessary to set this DTC are not present at this time.
2. Perform any Technical Service Bulletins that may apply to this condition.
3. With the scan tool, erase DTCs in the Wireless Control Module (WCM).
4. Test drive the vehicle for a minimum of 10 minutes with vehicle speed greater than 24 km/h (15 mph).
5. With the scan tool, read DTCs.
Does the DTC reset or is the status Active for this DTC?
Yes
- Repair as necessary.
- Perform the TPM VERIFICATION TEST. Tire Pressure Monitor (TPM) Verification Test.
No
- Test complete.