DTC B2274: Acc Relay Control Circuit

DTC detecting condition:

When malfunction is detected in ACC relay drive circuit in the keyless access Control Module or external circuit.

Trouble symptom:

Each function does not operate at the ACC position.

CAUTION: For replacement procedure of keyless access Control Module, refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume.

Wiring diagram:

Push button start system Ref. to WIRING DIAGRAM , Push Button Start System.

Fig 1: ACC Relay Control Circuit - Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

Step	Check	Yes	No
1 CHECK LAN SYSTEM. Inspect LAN system. Ref. to Basic Diagnostic Procedure , Basic Diagnostic Procedure.	Is LAN system normal?	Go to step 2 .	Perform the inspection according to the diagnosis for LAN system.
2 CHECK FUSE. Check the fuse. Ref. to Relay and Fuse .	Is the fuse OK?	Go to step 3 .	Replace the fuse. When the replaced fuse is blown immediately, check the power supply circuit for short-circuited.
3 CHECK HARNESS. Disconnect the keyless access Control Module connector. Using a tester, measure the voltage between the keyless access Control Module connector and chassis ground. Connector & terminal (B572) No. 2 (+) - Chassis ground (-):	Is the voltage 9.5 - 16 V?	Go to step 4 .	Check the power supply circuit.
4 CHECK HARNESS. Using a tester, measure the resistance between the keyless access Control Module connector and chassis ground. Connector & terminal (B572) No. 11 - Chassis ground:	Is the resistance less than 1 Ω?	Go to step 5 .	Repair or replace the open circuit of harness.
5 CHECK HARNESS. Disconnect the keyless access Control Module connector. Using a tester, measure the resistance between the keyless access Control Module connector and chassis ground. Connector & terminal (B574) No. 4 - Chassis ground:	Is resistance 152.61 - 216.5 Ω?(20°C)	Go to step 7 .	Go to step 6 .
6 CHECK RELAY. Perform inspection of ACC relay unit. Ref. to Accessory Relay (Push Button Start) .	Is the relay OK?	Go to step 7 .	Replace the relay.
7 CHECK HARNESS. Using a tester, measure the resistance between the keyless access Control Module connector and the accessory relay (push button start), and between the accessory relay (push button start) and chassis ground. Connector & terminal (B574) No. 4 - (B426) No. 1: (B426) No. 2 - Chassis ground:	Is the resistance less than 1 Ω?	Go to step 8 .	Repair or replace the open circuit of harness.
8 CHECK KEYLESS ACCESS CONTROL MODULE. Connect the keyless access Control Module connector. Using a tester, measure the voltage between the keyless access Control Module connector and chassis ground. Connector & terminal (B574) No. 4 (+) - Chassis ground (-):	Is the voltage 1 V or less → 9.5 - 16 V when OFF → ACC ON?	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.	Replace the keyless access Control Module. Ref. to Keyless Access Control Module .