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.

Wiring diagram: 

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

Courtesy of SUBARU OF AMERICA, INC.

1. 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.

2. 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.

3. 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.

4. 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.

5. 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 the resistance 152.61 - 216.5 O? (at 20°C)

   Yes: Go to  7.

   No: Go to  6.

6. CHECK RELAY  .

   Perform inspection of ACC relay unit. Ref. to SECURITY AND LOCKS>Relay and Fuse>INSPECTION>CHECK RELAY .

   Is the relay OK?

   Yes: Go to  7.

   No: Replace the relay. Ref. to SECURITY AND LOCKS>Accessory Relay (Push Button Start)>REMOVAL .

7. 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.

8. 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 (-):

   Does the voltage change as 1 V or less → 9.5 - 16 V according to the operation of 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>REMOVAL .