Stored Lost Communication DTCs

STORED LOST COMMUNICATION DTCS





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

- When Monitored:
With the ignition on for at least five seconds.

Battery voltage between 10 and 16 volts.

Body Control Module (BCM) is configured correctly.

- Set Condition:
Bus messages not received for approximately two to five seconds.





1. VERIFY DIAGNOSTIC TROUBLE CODE (DTC) IS STORED

NOTE: Stored faults may indicate a customer perceived intermittent condition.

NOTE: Make sure the battery voltage is between 10 and 16 volts before proceeding.

1. Turn the ignition on.
2. With the scan tool, read stored DTCs.

Is this DTC stored?

Yes

- Go To 2

No

- Go to and perform the appropriate diagnostic procedure.

2. CHECK THE ENVIRONMENTAL DATA
1. With the scan tool, read the loss of communication environmental data.

Does the loss of communication environmental odometer data match up to any of the previous service procedures listed in the possible causes or are there any stored CAN hardware electrical, battery, ignition voltage, VIN missing/mismatch, or BCM configuration DTCs present with matching environmental data?

Yes

- These DTCs may have been the result of other service procedures performed. Clear the DTCs.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 3

3. VERIFY INTERMITTENT LOST COMMUNICATION DTC - WIRING CONCERNS
1. With the scan tool, read all DTCs.

Is there more than one ECU with stored DTCs "Logged Against" the module and one or more lost communication DTCs stored in the offending module?

Yes

- Verify if the vehicle was recently in for this type of service. Otherwise, visually inspect the related wiring harness for chafed, pierced, pinched, and partially broken wires and the wiring harness connectors for broken, bent, pushed out, and corroded terminals. Repair as necessary.

No

- Go To 4

4. VERIFY INTERMITTENT LOST COMMUNICATION DTC - OFFENDING MODULE
1. With the scan tool, read all DTCs.

Is there more than one ECU with stored DTCs "Logged Against" the module and NO lost communication DTCs stored in the offending module?

Yes

- Check for a TSB related to this offending module.

No

- Go To 5

5. VERIFY INTERMITTENT LOST COMMUNICATION DTC - REPORTING MODULE
1. With the scan tool, read all DTCs.

Is there ONLY ONE ECU with stored DTCs "Logged Against" the module?

Yes

- Check for a TSB related to the module that set this DTC.

No

- Verify if the vehicle was recently in for this type of service. Otherwise, visually inspect the related wiring harness for chafed, pierced, pinched, and partially broken wires and the wiring harness connectors for broken, bent, pushed out, and corroded terminals. Repair as necessary.