Hands Free Module (HFM)
U0019-CAN B BUS
For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.
- When Monitored:
Continuously
- Set Condition:
Whenever the CAN B Bus (+) or CAN B Bus (-) circuit is open, shorted to voltage or shorted to ground.
1. CHECK FOR ACTIVE DTCS
1. With the scan tool, read the active DTCs.
2. Cycle the ignition switch from off to on at least 5 times, leaving the ignition on for a minimum of 90 seconds per cycle.
3. With the scan tool, read the active DTCs.
Does the scan tool display this DTC as active?
Yes
- Go To 2
No
- If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.
- Perform the BODY VERIFICATION TEST. Body Verification Test
2. CHECK THE TOTALLY INTEGRATED POWER MODULE DTCs
1. With the scan tool, read the Totally Integrated Power Module active DTCs.
Does the scan tool display any CAN B BUS DTCs - ACTIVE?
Yes
- Totally Integrated Power Module (TIPM)
No
- Go To 3
3. (D55) CAN B BUS (+) CIRCUIT OPEN
1. Turn the ignition off.
2. Disconnect the negative battery cable.
3. Disconnect the Hands Free Module harness connector.
4. Disconnect the Totally Integrated Power Module harness connector.
5. Measure the resistance of the (D55) CAN B Bus (+) circuit between the Totally Integrated Power Module connector and the Hands Free Module connector.
Is the resistance below 2.0 ohms?
Yes
- Go To 4
No
- Repair the (D55) CAN B Bus (+) circuit for an open.
- Perform the BODY VERIFICATION TEST. Body Verification Test
4. (D54) CAN B BUS (-) CIRCUIT OPEN
1. Measure the resistance of the (D54) CAN B Bus (-) circuit between the Totally Integrated Power Module connector and the Hands Free Module connector.
Is the resistance below 2.0 ohms?
Yes
- Replace the Hands Free Module.
- Perform the BODY VERIFICATION TEST. Body Verification Test
No
- Repair the (D54) CAN B Bus (-) circuit for an open.
- Perform the BODY VERIFICATION TEST. Body Verification Test