DTC U0427 Invalid Data Received From Vehicle Security Control Module: Trouble Symptom

Cooperation control of keyless access does not operate properly.

DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK PERFORMING OF BASIC DIAGNOSTIC PROCEDURE.	Was the basic diagnostic procedure performed up to STEP 8?	Go to step 2.	Perform the basic diagnostic procedure. < Ref. to BASIC DIAGNOSTIC PROCEDURE . >
2 CHECK DTC. Check the displayed DTC.	Are DTCs other than U*** displayed?	Perform the diagnosis according to DTC.	Go to step 3.
3 CHECK DTC. Check the displayed DTC.	Is DTC for the bus off or the data no-receive displayed?	Perform the diagnosis according to DTC.	Go to step 4.
4 CHECK DTC. Check the displayed DTC.	Is U0427 a current malfunction?	Go to step 5.	Go to step 9.
5 CHECK DTC. Turn the ignition switch to OFF. Disconnect the keyless access CM connector. Connect the disconnected connectors. Read the DTC using Subaru Select Monitor.	Is U0427 a current malfunction?	Go to step 6.	Go to step 9.
6 CHECK DTC. Using the Subaru Select Monitor, read DTC of all the systems.	Is the smart data abnormal detected in several modules?	Replace the keyless access CM. < Ref. to KEYLESS ACCESS CM . >	Go to step 7.
7 REPLACE MODULE. Replace the keyless access CM. < Ref. to KEYLESS ACCESS CM . > NOTE: Do not register the keyless access CM. Read the DTC using Subaru Select Monitor.	Is U0427 a current malfunction?	Go to step 8.	System is normal. NOTE: Register the keyless access CM.
8 CHECK MODULE. Reinstall the keyless access CM. Replace the body integrated unit. < Ref. to BODY INTEGRATED UNIT . > Read the DTC using Subaru Select Monitor.	Is U0427 a current malfunction?	Replace the keyless access CM. < Ref. to KEYLESS ACCESS CM . >	System is normal.
9 CHECK HARNESS. Shake the harness, and check for poor contact. Read the DTC using Subaru Select Monitor.	Is U0427 a current malfunction?	Repair the poor contact of harness, or replace the harness.	Go to step 10.
10 CHECK CONNECTOR. Check the connector used for high speed CAN for poor contact.	Is there poor contact of connector?	Repair the connector that has poor contact, or replace harness.	It is possible that temporary poor communication occurs. Delete the DTC.