2007 Liberty KJ Factory Service Manual 22 - TIRES/WHEELS

TIRE PRESSURE SENSOR LOCATION UNDETEREMIND

For a complete wiring diagram Refer to Section 8W.

Theory of Operation


The vehicle sensor locate process occurs after the vehicle sits at zero speed for more than 19 min. The tire pressure monitor system will determined the sensor positions while driving at speeds above 15 MPH (24 Km/h). This process can take up to 10 min to determined sensor positions.



Possible Causes
 
(D508) COM - LIN TIRE PRESSURE MONITOR LAN CIRCUIT SHORT TO VOLTAGE
 
(D508) COM - LIN TIRE PRESSURE MONITOR LAN CIRCUIT SHORT TO GROUND
 
(D508) COM - LIN TIRE PRESSURE MONITOR LAN CIRCUIT OPEN OR HIGH RESISTANCE
 
FUSED IGNITION SWITCH OUTPUT (RUN) CIRCUIT OPEN OR HIGH RESISTANCE
 
GROUND CIRCUIT(S) OPEN OR HIGH RESISTANCE
 
(D508) COM-LIN TIRE PRESSURE MONITOR LAN CIRCUIT OPEN
 
TIRE PRESSURE TRIGGER MODULE POWER AND GROUND
 
TPM SENSOR
 
WCM
 




Diagnostic Test

1. OTHER DTC'S SET

Repair all other DTC's first.

Is this DTC still active after all other DTC's repaired?

Yes


No

2. VERIFY DTC IS ACTIVE

NOTE: Ensure the IOD fuse is installed and battery voltage is between 10 and 16 volts before proceeding.


Turn the ignition on.
With the scan tool, read and record WCM DTCs.
With the scan tool, erase WCM DTCs.
Cycle the ignition switch.
With the scan tool, read WCM DTCs.

Does this DTC reset?

Yes


No

3. (D508) COM-LIN TIRE PRESSURE MONITOR LAN CIRCUIT OPEN

Turn the ignition off.
Disconnect the Tire Pressure Trigger Module.
Disconnect the WCM.
With an ohmmeter measure the resistance of the (D508) COM-LIN TIRE PRESSURE MONITOR LAN CIRCUIT.

Is the resistance below 5 Ohms?

Yes


No

4. FUSED IGNITION SWITCH OUTPUT (RUN) CIRCUIT OPEN OR HIGH RESISTANCE



Turn the ignition off.
Disconnect the Tire Pressure Transponder harness connector.
Disconnect the Sentry Key Remote Entry Module harness connector.
Turn the ignition on.
Using a 12–volt test light connect to ground, check the Fused Ignition Switch Output (Run) circuit.

NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.



Is the test light illuminated and bright?

Yes


No

5. GROUND CIRCUIT(S) OPEN OR HIGH RESISTANCE

Using a 12-volt test light connect to battery voltage, probe each of the Ground circuit(s).

NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.



Does the test light illuminate brightly?

Yes


No

6. (D508) COM - LIN TIRE PRESSURE MONITOR LAN CIRCUIT SHORT TO VOLTAGE



Turn the ignition on.
Measure the voltage of the (D508) COM - LIN Tire Pressure Monitor LAN circuit.

Is there any voltage present?

Yes


No

7. (D508) COM - LIN TIRE PRESSURE MONITOR LAN CIRCUIT SHORT TO GROUND



Turn the ignition off.
Measure the resistance between ground and the (D508) COM - LIN Tire Pressure Monitor LAN circuit.

Is the resistance below 5.0 ohms?

Yes


No

8. (D508) COM - LIN TIRE PRESSURE MONITOR LAN CIRCUIT OPEN OR HIGH RESISTANCE



Use a jumper wire with one end connected to ground and the other to the (D508) COM - LIN Tire Pressure Monitor LAN circuit in the Front Left Pressure Tire Transponder harness connector.
Using a 12-Volt test light connected to battery voltage, probe the (D508) COM - LIN Tire Pressure Monitor LAN circuit in the TPM harness connector.

NOTE: The test light should be illuminated and bright. Compared the brightness to that of a direct connection to the battery.



Does the test light illuminate bright?

Yes


No

9. POWER AND GROUND CIRCUIT OPEN

Turn the ignition on.
With a voltmeter measure the voltage between the power and ground circuit at the Trigger Module.

Is the voltage at least the same as battery voltage?

Yes


No

10. CHECK FOR ADDITIONAL TRIGGER MODULE COMMUNICATION RELATED DTCs

With the scan tool, select Network View and select Advanced.

Is there more than one module with active DTCs “Logged Against” the WCM?

Yes


No