U1114

U1114-LOST COMMUNICATION WITH LEFT FRONT TIRE PRESSURE TRIGGER MODULE





For a complete wiring diagram Refer to Diagrams/Electrical. Electrical Diagrams


- When Monitored:

- With the ignition on
- Battery voltage between 10 and 16 volts
- IOD fuse installed

- Set Condition:

If the WCM fails to receive bus messages from the Tire pressure trigger module for two consecutive counts of trigger module not responding to a communication check.







Diagnostic Test


1. DTC STATUS

Ensure every trigger module connector is connected and WCM connected.

Turn the ignition on.

With the scan tool, run the "Trigger Module Test Routine" under "Miscellaneous Functions" for the "WCM" and follow the procedure.


NOTE: Three trigger modules are located in three of the four wheel wells on the vehicle to provide the WCM/SKREEM with the location of the tire pressure sensors on the vehicle. A fourth transponder is not necessary in the remaining wheel well due to the process-of-elimination theory. Once the system knows the location of the first three sensors it assumes the location of the fourth tire pressure sensor. The locations of the trigger modules can vary for each vehicle. Make sure the vehicle has trigger modules, and that are in the right locations. After every repair, the trigger module test routine must be rerun in order to verify the fix.

Did the Left Front Trigger Module have NO as a result?

Yes

- Go To 2

No

- Repair intermittent condition.


2. (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

- Go To 3

No

- Repair or replace the open circuit.
- Perform TPM VERIFICATION TEST. Tire Pressure Monitor (TPM) Verification Test


3. (F202) 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 (F202) 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

- Go to 4

No

- Repair the (F202) Fused Ignition Switch Output (Run) circuit for an open circuit or high resistance.
- Perform TPM VERIFICATION TEST. Tire Pressure Monitor (TPM) Verification Test


4. (Z904) GROUND CIRCUIT(S) OPEN OR HIGH RESISTANCE





Using a 12-volt test light connect to battery voltage, probe each of the (Z904) 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

- Go to 5

No

- Repair the (Z904) Ground circuit(s) for an open circuit or high resistance.
- Perform TPM VERIFICATION TEST. Tire Pressure Monitor (TPM) Verification Test


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





Turn the ignition off.

Disconnect all three tire pressure transponder harness connectors.

Turn the ignition on.

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

Is there any voltage present?

Yes

- Repair the (D508) COM - LIN Tire Pressure Monitor LAN circuit for a short to voltage.
- Perform TPM VERIFICATION TEST. Tire Pressure Monitor (TPM) Verification Test

No

- Go to 6


6. (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

- Repair the (D508) COM - LIN Tire Pressure Monitor LAN circuit for a short to ground.
- Perform TPM VERIFICATION TEST. Tire Pressure Monitor (TPM) Verification Test

No

- Go to 7


7. (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

- Go to 8

No

- Repair the (D508) COM - LIN Tire Pressure Monitor LAN circuit for an open circuit or high resistance.
- Perform TPM VERIFICATION TEST. Tire Pressure Monitor (TPM) Verification Test


8. 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

- Go To 9

No

- Repair the open circuit.
- Perform TPM VERIFICATION TEST. Tire Pressure Monitor (TPM) Verification Test


9. 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

- Replace/update the WCM.
- Perform TPM VERIFICATION TEST. Tire Pressure Monitor (TPM) Verification Test

No

- Replace the Tire pressure trigger Module.
- Perform TPM VERIFICATION TEST. Tire Pressure Monitor (TPM) Verification Test