U0197

U0197-LOST COMMUNICATION WITH HANDS FREE MODULE (HFM)





For a complete wiring diagram, refer to the Wiring Information.

- When Monitored:
With the ignition on.

Battery voltage between 10 and 16 volts.

IOD fuse installed.

Totally Integrated Power Module (TIPM) is configured correctly.

- Set Condition:
Bus messages not received from the Hands Free Module (HFM) for approximately 2 to 5 seconds.





1. VERIFY THE DIAGNOSTIC TROUBLE CODE (DTC) IS ACTIVE

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

1. With the scan tool, read active DTCs.

Is this DTC active?

Yes

- Go To 2

No

- Refer to the Stored Lost Communication diagnostic procedure. Stored Lost Communication DTCs

2. CHECK FOR ANY OF THE FOLLOWING ACTIVE DTCS
1. With the scan tool, read active DTCs from all modules.

NOTE: 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

- Go to and perform the appropriate diagnostic procedure.

No

- Go To 3

3. VERIFY THAT THE HFM IS ACTIVE ON THE BUS
1. Turn the ignition on.
2. With the scan tool, select Network Diagnostics.
3. Verify that the HFM is active on the bus.

Is the HFM active on the bus?

Yes

- Go To 4

No

- Perform the No Response diagnostic procedure. Manufacturer Code Charts

4. CHECK FOR ADDITIONAL COMMUNICATION RELATED DTCS
1. 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 Module.
- Perform the BODY VERIFICATION TEST. Body Verification Test

No

- Go To 5

5. CLEAR DTC IN MODULE SETTING FAULT
1. With the scan tool, select the module setting the DTC against the HFM.
2. Clear active DTCs.

Is this DTC still active?

Yes

- Replace/update the module that set this DTC.
- Perform the BODY VERIFICATION TEST. Body Verification Test

No

- Go To 6

6. CYCLE IGNITION
1. 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 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. Body Verification Test

7. CHECK FOR ADDITIONAL LOST COMMUNICATION FAULTS
1. 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 8

No

- Replace/update the module that set this DTC.
- Perform the BODY VERIFICATION TEST. Body Verification Test

8. (D265) CAN INTERIOR BUS(+) (125K) CIRCUIT SHORTED TO VOLTAGE
1. Measure the voltage between the (D265) CAN Interior Bus(+) (125K) circuit and ground.

Is the voltage above 5 volts?

Yes

- Repair the (D265) CAN Interior Bus(+) (125K) circuit for a short to voltage.
- Perform the BODY VERIFICATION TEST. Body Verification Test

No

- Go To 9

9. (D264) CAN INTERIOR BUS(-) (125K) CIRCUIT SHORTED TO GROUND
1. Turn the ignition off.
2. Measure the resistance between ground and the (D264) CAN Interior Bus(-) (125K) circuit.

Is the resistance below 10K Ohms?

Yes

- Repair the (D264) CAN Interior Bus(-) (125K) circuit for a short to ground.
- Perform the BODY VERIFICATION TEST. Body Verification Test

No

- Replace/update the module that set this DTC.
- Perform the BODY VERIFICATION TEST. Body Verification Test