2007 Liberty KJ Factory Service Manual 22 - TIRES/WHEELS

LOW TIRE PRESSURE

For a complete wiring diagram Refer to Section 8W.



Possible Causes
  
INTERMITTENT PERFORMANCE DTC
  
LOW TIRE PRESSURE
  
TIRE PRESSURE SENSOR
  
WCM (SKREEM)
  



Diagnostic Test

1. DTC STATUS IS ACTIVE

NOTE:

If the vehicle has a flat tire.

Complete all tire repairs before following this procedure.

One or more of the following DTC's can be set if a tirre without a Tire Pressure Monitoring Sensor is in use.

Low Tire Pressure DTC.

Tire Pressure Sensor Internal DTC.


Repair the original road tire and place it back on the vehicle in place of the non-sensored tire.
Test drive the vehicle.
If the DTC(s) reset continue with the diagnostic procedure.
Turn the ignition on.
With the scan tool, select View DTCs in the Wireless Control Module (SKREEM).

Is the DTC status Active at this time?

Yes


No

2. LOW TIRE PRESSURE

NOTE: The DTC can be caused by many different factors and might not be a sensor/transmitter or a WCM (SKREEM) 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 threshold. Tire pressure should always be set based on cold inflation tire pressure (placard).


Inflate all tire pressures to the recommended cold inflation tire pressure and wait 2 minutes.
The placard is located on the Driver's B-pillar.
With the scan tool, clear DTCs in the Wireless Control Module (SKREEM).
Test Drive the vehicle for a minimum of 10 minutes with vehicle speed greater than 15 m.p.h.
With the scan tool, select View DTCs in the Wireless Control Module (SKREEM).

Does the DTC reset or is the status Active for this DTC?

Yes


No

3. TIRE PRESSURE 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.


Turn the ignition on.
Look for a tire pressure sensor that is not transmitting. Use one or more of the following methods:

NOTE: The following test(s) is to locate the Tire Pressure Sensor/Transmitter. If the tires have been rotated, the Tire Pressure 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 Sensor/Transmitter that set the fault before continuing.


METHOD 1: If available, use a TPM-RKE Analyzer #9936 tool to scan each tire pressure sensor. The faulty sensor can not be activated by the tool. If a suspected sensor has been located, check it by lowering the tire pressure to see if a fault was set.
If the TPMS fault was detected and not associated to this Sensor/Transmitter, repeat the process until the faulty Sensor/Transmitter has been identified.
METHOD 2: Starting with the left front wheel, deflate the tire to 20 PSI and wait 2 minutes. The fault will set once the pressure has reached 20 PSI within the 2 minute time frame.
If the TPMS fault was detected and not associated to this Sensor/Transmitter, repeat the process on each wheel on the vehicle until the faulty Sensor/Transmitter has been identified.

NOTE: Once a fault/alert has set, it will establish the location of the tire pressure sensors/transmitter. Repeat steps until the applicable Tire Pressure Sensor/Transmitter has been located.



Has a faulty sensor been located?

Yes


No

4. INTERMITTENT TIRE PRESSURE SENSOR DTC

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.


NOTE: The DTC can be caused by many different factors and might not be a sensor/transmitter or a WCM (SKREEM) 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.


The conditions necessary to set this DTC are not present at this time.
Refer to any Technical Service Bulletins that may apply to this condition.
With the scan tool, clear DTCs in the Wireless Control Module (SKREEM).
Test Drive the vehicle for a minimum of 10 minutes with vehicle speed greater than 15 m.p.h.
With the scan tool, select View DTCs in the Wireless Control Module (SKREEM).

Does the DTC reset or is the status Active for this DTC?

Yes


No