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Lost Communication With Hands Free Phone Module






U0197 - Lost Communication with Hands Free Phone Module






For a complete wiring diagram, refer to.

When Monitored: With the ignition on. Battery voltage between 10 and 16 volts. IOD fuse installed. TIPM is configured correctly.

Set Condition: Bus messages not received from the hands free phone module for approximately 2 to 5 seconds.






Test Step 1 - VERIFY DTC IS ACTIVE

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

With the scan tool, read active DTCs.

Is this DTC active?

Yes

Go to Test Step 2.

No

Perform the Stored Lost Communication diagnostic procedure. Refer to => Non-DTC Based Diagnostics. Stored Lost Communication DTCs

Test Step 2 - Check for Any of the Following Active DTCs

With the scan tool, read active DTCs from all modules.

Check for TIPM configuration, CAN interior bus hardware electrical, VIN missing/mismatch, battery or ignition related DTCs.

Does the scan tool display any active DTCs to the conditions listed above?

Yes

Diagnose and repair the DTC. Refer to the Index for a complete list of the symptoms.

No

Go to Test Step 3.

Test Step 3 - Verify that the HFM is Active on the Bus

Turn the ignition ON.

With the scan tool, select network diagnostics.

Verify that the HFM is active on the bus.

Is the HFM active on the bus?

Yes

Go to Test Step 4.

No

Perform the No Response diagnostic procedure. Refer to => Non-DTC Based Diagnostics.

Test Step 4 - Check for Additional Communication Related DTCs

With the scan tool, select network diagnostics.

Is there more than one module with active DTCs logged against the HFM?

Yes

Replace/update the hands free phone module.

Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior

No

Go to Test Step 5.

Test Step 5 - Clear DTC in Module Setting Fault

With the scan tool, select the module setting the DTC against the HFM.

Clear active DTCs.

Is this DTC still active?

Yes

Replace/update the module that set this DTC.

Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior

No

Go to Test Step 6.

Test Step 6 - Cycle Ignition

Cycle the ignition from RUN to OFF three times ending with the key in the RUN position.

Does this DTC become active?

Yes

Go to Test Step 7.

No

The condition is not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring for chafed, pierced, pinched, and partially broken wires and the wiring harness connectors for broken, bent, pushed out, and corroded terminals.

Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior

Test Step 7 - Check for Additional Lost Communication Faults

With the scan tool, select network diagnostics.

Does the TIPM and other CAN interior bus 125K modules show lost communication with the remaining CAN interior bus 125K modules?

Yes

Go to Test Step 8.

No

Replace/update the module that set this DTC.

Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior

Test Step 8 - CAN Interior Bus (+) 125K Circuit Short to Voltage

Measure the voltage between the CAN interior bus (+) 125K circuit and ground.

Is the voltage more than 5 volts?

Yes

Repair the CAN interior bus (+) 125K circuit for a short to voltage.

Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior

No

Go to Test Step 9.

Test Step 9 - CAN Interior Bus (-) 125K Circuit Short to Ground

Turn the ignition OFF.

Measure the resistance between ground and the CAN interior bus (-) 125K circuit.

Is the resistance less than 10K ohms?

Yes

Repair the CAN interior bus (-) 125K circuit for a short to ground.

Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior

No

Replace/update the module that set this DTC.

Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior