DTC U1101 (No. 1101): Lost Communication With TCM: Troubleshooting

DTC TROUBLESHOOTING CHART

Step	Action	YES	NO
1	Check DTC in BCM Is DTC U1101 (No. 1101) and DTC U1073 (No. 1073) detected together?	Go to DTC U1073 (NO. 1073): CONTROL MODULE COMMUNICATION BUS OFF .	Go to Step 2.
2	Check DTC in TCM Check DTC for TCM. Is DTC U0073 detected?	Go to DTC U0073: CONTROL MODULE COMMUNICATION BUS OFF .	Go to Step 3.
3	Check each control module connectors Check connection of connectors of all control modules communicating by means of CAN. Recheck BCM for DTC. Is DTC U1101 (No. 1101) detected?	Go to Step 4.	Intermittent trouble. Check for intermittent referring to INTERMITTENT AND POOR CONNECTION INSPECTION .
4	CAN communication circuit check Turn ignition switch to OFF position. Disconnect connectors of BCM and TCM communicating by means of CAN. Check CAN communication circuit between BCM and TCM for open, short and high resistance. Is each CAN communication circuit in good condition?	Go to Step 5.	Repair circuit.
5	DTC check Turn ignition switch to OFF position. Disconnect connectors of all control modules communicating by means of CAN. Connect connectors to BCM and TCM. Recheck BCM for DTC. Is DTC U1101 (No. 1101) detected?	Go to Step 6.	Go to Step 7.
6	DTC Check Turn ignition switch to OFF position. Connect connectors to ECM and ABS or ESP® control module. Check DTC for ECM. Is DTC U0101 detected by ECM?	Check TCM power and ground circuit. If circuit is OK, substitute a known-good TCM and recheck.	Substitute a known-good BCM and recheck.
7	CAN communication circuit check Turn ignition switch to OFF position. Check each CAN communication circuit between disconnected control modules (other than BCM and TCM) for open, short and high resistance. Is each CAN communication circuit in good condition?	Go to Step 8.	Repair circuit.
8	Check DTC in BCM Connect connectors of disconnected control modules communicating by means of CAN. Disconnect connector from any one of control modules other than BCM. Recheck DTC for BCM. Is DTC U1101 detected?	Disconnect connectors of control modules other than the one whose connector is disconnected in Step 2) one by one and check that DTC U1101 is detected by BCM each time connector is disconnected. When DTC U1101 is not detected by BCM while checking in this way, go to description under "NO" below. If DTC U1101 is detected by BCM even when connectors of all control modules that use CAN communication with BCM are disconnected, substitute a known-good BCM and recheck.	Check power and ground circuit of control module disconnect in Step 2). If circuit is OK, substitute a known-good control module disconnected in Step 2) and recheck.