Operation CHARM: Car repair manuals for everyone.

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.

Ignition Off Draw (IOD) fuse installed.

Totally Integrated Power Module (TIPM) is configured correctly.

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





Diagnostic Test

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. With the scan tool, read stored DTCs.

Is this DTC stored?

Yes
- Go To 2

No
- Diagnose the active DTC.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

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 B or C hardware electrical, battery, ignition voltage, VIN missing/mismatch, TIPM configuration DTCs present with match 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. With the scan tool, view all the modules.

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. With the scan tool, view all the modules.

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 Bulletins (TSBs) related to this offending module.

No
- Go To 5

5. VERIFY INTERMITTENT LOST COMMUNICATION DTC - REPORTING MODULE
1. Turn the ignition on.
2. With the scan tool, view all the modules.

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

Yes
- Check for TSBs 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.