7000 - 7999: 7220

7220- LOST COMMUNICATION WITH TCM

For a complete wiring diagram, Refer to the Wiring Information Electrical Diagrams.

- When Monitored:
With the ignition on.

Battery voltage between 10 and 16 volts.

IOD fuse installed.

BCM is configured correctly.

- Set Condition:
Bus messages not received from the TCM for approximately 500 ms.





1. VERIFY 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

- Perform the Loss of Communication with TCM diagnostic procedure.Communications - Verbose Codes

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

NOTE: Check for BCM configuration, CAN B or C hardware electrical, VIN Missing/Mismatch, battery or ignition related DTCs.

Does the scan tool display any active DTCs to the conditions listed above?

Yes

- Perform the appropriate diagnostic procedure.Testing and Inspection

No

- Go To 3

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

Is the TCM active on the bus?

Yes

- Go To 4

No

- For No Response with TCM diagnostic procedures.No Response From TCM (Transmission Control Module)
- Perform the BODY VERIFICATION TEST Body Verification Test.

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 TCM?

Yes

- Replace/update the TCM.
- Perform the NAG1 TRANSMISSION VERIFICATION TEST. Transmission Verification Test.

No

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