DTC U121B Can-HS A/C Data Abnormal: Trouble Symptom

Cooperation control of air conditioner does not operate properly.

DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK DTC. Using the Subaru Select Monitor, read all DTCs.	Is there DTC other than CAN system?	Perform the diagnosis according to DTCs for other control modules.	Go to step 2 .
2 CHECK DTC. Check DTC indicated in CAN system.	Is U121B a current malfunction?	Go to step 3 .	Go to step 4 .
3 CHECK DTC. Turn the ignition switch to OFF, and read the DTC again.	Is U121B a current malfunction?	Replace the A/C CM. Refer to REMOVAL .	Go to step 4 .
4 CHECK A/C CM. Disconnect the A/C CM connector. Using the Subaru Select Monitor, perform the clear memory. Using the Subaru Select Monitor, read DTC of CAN system.	Is the displayed DTC other than U121B?	Go to step 5 .	Replace the A/C CM. Refer to REMOVAL .
5 CHECK A/C CM. Connect the A/C CM connector. Using the Subaru Select Monitor, read DTC of A/C CM. Refer to OPERATION .	Is DTC other than CAN system displayed?	Perform the diagnosis according to DTC.	Replace the body integrated unit. Refer to REMOVAL .