Without Keyless Access With Push Button Start System

DTC detecting condition:

UART between the TPMS & keyless entry Control Module and the body integrated unit is open or shorted, or has communication failure.
Communication with TPMS & keyless entry Control Module is faulty.

Time needed for diagnosis:

10 times

Trouble symptom:

Door lock does not operate with keyless.

Wiring diagram:

NOTE: For the coupling connector, refer to "WIRING SYSTEM".
Keyless entry system <Ref. to WIRING DIAGRAM , Keyless Entry System.>

Fig 1: Keyless UART Com. Malfunction Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

Step	Check	Yes	No
1 CHECK DTC. Insert the ignition key to the ignition key cylinder and remove. Read the DTC of body integrated unit using Subaru Select Monitor. <Ref. to READ DIAGNOSTIC TROUBLE CODE (DTC) .>	Is DTC U1500 displayed? (Current malfunction)	Go to step 2.	Go to step 7.
2 CHECK DTC. Turn the ignition switch to OFF. Disconnect the body integrated unit and the TPMS & keyless entry Control Module connector. Connect the disconnected connectors. Insert the ignition key to the ignition key cylinder and remove. Read the DTC of body integrated unit using Subaru Select Monitor. <Ref. to READ DIAGNOSTIC TROUBLE CODE (DTC) .>	Is DTC U1500 displayed? (Current malfunction)	Go to step 3.	Go to step 7.
3 CHECK HARNESS (OPEN CIRCUIT). Turn the ignition switch to OFF. Disconnect the body integrated unit and the TPMS & keyless entry Control Module connector. Using the tester, measure the resistance between terminals. Connector & terminal (i81) No. 10 - (R221) No. 11:	Is the resistance 10 Ω or less?	Go to step 4.	Repair the open circuit of harness or replace harness.
4 CHECK HARNESS. Turn the ignition switch to ON. Use a tester to measure the voltage between the terminals. Connector & terminal (R221) No. 4 (+) - Chassis ground (-): (R221) No. 6 (+) - Chassis ground (-):	Is the voltage 10 V or more?	Go to step 5.	Repair or replace the open circuit of harness.
5 CHECK HARNESS (OPEN CIRCUIT). Turn the ignition switch to OFF. Using the tester, measure the resistance between terminals. Connector & terminal (R221) No. 5 - Chassis ground:	Is the resistance 10 Ω or less?	Go to step 6.	Repair or replace the open circuit of harness.
6 CHECK DTC. Connect all the disconnected connectors. Turn the ignition switch to ON. Read the DTC of body integrated unit using Subaru Select Monitor. <Ref. to READ DIAGNOSTIC TROUBLE CODE (DTC) .>	Is any DTC other than U1500 displayed?	Replace the body integrated unit. <Ref. to BODY INTEGRATED UNIT .>	Replace the TPMS & keyless entry Control Module. <Ref. to REMOVAL , Keyless Entry Control Module.>
7 CHECK CONNECTOR. Check for a poor contact between the body integrated unit and the TPMS & keyless entry Control Module connector.	Is there poor contact of connector?	Repair the connector that has poor contact, or replace harness.	Even if DTC is displayed, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again. NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.