Refer to "Shop Manual" and remove necessary parts to allow access to Cluster, ACU, ECM and other control units that connected to C-CAN Communication circuit.

Connect GDS to Data Link Connector (DLC).

Ignition "ON"

Disconnect unit connector one at a time.

Check for control unit causing the fault by communicating with Cluster, ACU, ECM and other systems with GDS.

Does the status of DTC U000100 changes to "History" when certain control module connector is disconnected?

	▶ Carefully re-do this troubleshooting guide steps. ▶ If no problems were found with the circuits or connectors, replace control unit that causing the fault and then go to "Verification of Vehicle Repair" procedure.
	▶ Carefully re-do this troubleshooting guide steps. ▶ If no problems were found with the circuits or connectors, replace ECM and then go to "Verification of Vehicle Repair" procedure.