Stored Lost Communication DTCs

STORED LOST COMMUNICATION DTCS





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.

Front Control Module (FCM) 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 IOD fuse is installed and battery voltage is between 10 and 16 volts before proceeding.

1. Using 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. Using 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 their any stored CAN B or C hardware electrical, battery, ignition voltage, VIN missing/mismatch, FCM configuration DTCs present with matching environmental data?

Yes

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

No

- Go To 3

3. VERIFY INTERMITTENT LOST COMMUNICATION DTC - WIRING CONCERNS
1. Turn the ignition on.
2. Using the scan tool, select Network Diagnostics.

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.
- Perform the BODY VERIFICATION TEST. Body Verification Test

No

- Go To 4

4. VERIFY INTERMITTENT LOST COMMUNICATION DTC - OFFENDING MODULE
1. Turn the ignition on.
2. Using the scan tool, select Network Diagnostics.

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 Technical Service Bulletin (TSB) related to this offending module.

No

- Go To 5

5. VERIFY INTERMITTENT LOST COMMUNICATION DTC - REPORTING MODULE
1. Turn the ignition on.
2. Using the scan tool, select Network Diagnostics.

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

Yes

- Check for 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.
- Perform the BODY VERIFICATION TEST. Body Verification Test