Antilock Brake/Traction Control System

U0101-LOST COMMUNICATION WITH TCM





When Monitored
^ With the ignition on
^ Battery voltage between 10 and 16 volts
^ IOD fuse installed
^ FCM is configured correctly

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

Possible Causes
- CAN B OR CAN C BUS CIRCUITS OPEN OR SHORTED
- DTCS RELATED TO BATTERY VOLTAGE, IGNITION, OR VIN MESSAGES
- FCM NOT CONFIGURED CORRECTLY
- TCM
- TCM POWER AND GROUND
- MODULE THAT SET THIS DTC

Diagnostic Test
1. VERIFY DTC IS ACTIVE





NOTE: Ensure the IOD fuse is installed and battery voltage is between 10 and 16 volts before proceeding.

With the scan tool, read active DTCs.

Is this DTC active?
Yes >> Go To 2
No >> Refer to the Stored Lost Communication test procedure.
Perform BODY VERIFICATION TEST VER - 1. Body Verification Test
2. CHECK FOR ANY OF THE FOLLOWING ACTIVE DTCS





With the scan tool, read all active DTCs from all modules.

NOTE: Check for FCM 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 >> Diagnose and repair the DTC. Refer to the Table of Con tents for a complete list of the symptoms.
Perform BODY VERIFICATION TEST VER - 1. Body Verification Test
No >> Go To 3
3. VERIFY THAT THE TCM IS ACTIVE ON THE BUS





Turn the ignition on.
With the scan tool, select Network Diagnostics.
Verify that the TCM is active on the bus.

Is the TCM active on the bus?
Yes >> Go To 4
No >> Refer to a no response test procedure.
Perform BODY VERIFICATION TEST VER - 1. Body Verification Test
4. CHECK FOR ADDITIONAL COMMUNICATION RELATED DTCS





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 in accordance with the service information.
Perform BODY VERIFICATION TEST VER - 1. Body Verification Test
No >> Replace/update the module that set this DTC in accordance with the service information.
Perform BODY VERIFICATION TEST VER - 1. Body Verification Test