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. Contact an Authorized Subaru Dealership.

Wiring diagram:

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

Engine type: FA

Courtesy of SUBARU OF AMERICA, INC.
Engine type: EJ

Courtesy of SUBARU OF AMERICA, INC.

CHECK LAN SYSTEM .
Inspect LAN system. Ref. to LAN SYSTEM (DIAGNOSTICS)>Basic Diagnostic Procedure>PROCEDURE

Is the check result OK?

Yes: Go to 2

No: Perform the inspection according to the diagnosis for LAN system.
CHECK FUSE .
Check the fuse. Ref. to SECURITY AND LOCKS>Relay and Fuse

Is the check result OK?

Yes: Go to 3

No: Replace the fuse. When the replaced fuse is blown immediately, check the power supply circuit for short-circuited.
CHECK HARNESS .
1. Disconnect the keyless access CONTROL MODULE connector.
2. Using a tester, measure the resistance between the keyless access CONTROL MODULE connector and chassis ground.
  Connector & terminal
  
  (B572) No. 2 (+) - Chassis ground (-):
Is the voltage 9.5 - 16 V?

Yes: Go to 4

No: Check the power supply circuit.
CHECK HARNESS (OPEN CIRCUIT) .
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?

Yes: Go to 5

No: Repair or replace the open circuit of harness.
CHECK HARNESS .
1. Disconnect the keyless access CONTROL MODULE connector.
2. 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)

Yes: Go to 7

No: Go to 6
CHECK RELAY .
Perform inspection of ACC relay unit. Ref. to SECURITY AND LOCKS>Accessory Relay (Push Button Start)

Is the check result OK?

Yes: Go to 7

No: Replace the relay.
CHECK HARNESS (OPEN CIRCUIT) .
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?

Yes: Go to 8

No: Repair or replace the open circuit of harness.
CHECK KEYLESS ACCESS CONTROL MODULE .
1. Connect the keyless access CONTROL MODULE connector.
2. 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?

Yes: 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.

No: Replace the keyless access CONTROL MODULE. Ref. to SECURITY AND LOCKS>Keyless Access CONTROL MODULE