DTC B2788: IGN Signal Correlation (Steering Lock Control Module)

DTC detecting condition: 

When mismatch of the ignition switch status of LIN communication and direct line continued for one second.

Trouble symptom: 

The steering lock cannot be released.

Wiring diagram: 

Push button start system. Refer 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.

1. CHECK FUSE. 

   Check the fuse. Refer to SECURITY AND LOCKS>RELAY AND FUSE>INSPECTION .

   Is the check result OK?

   Yes:  Go to  2.

   No:  Replace the fuse. When the replaced fuse is blown immediately, check the power supply circuit for short-circuited.

2. CHECK DATA MONITOR. 

   Using the Subaru Select Monitor, check the following items on «Data monitor» of «Keyless Access with Push Button Start». Refer to KEYLESS ACCESS WITH PUSH BUTTON START SYSTEM (DIAGNOSTICS)>DATA MONITOR .

   • «IGN1/2 relay monitor (drive output)»

   Is the display normal according to the ignition switch operation?

   Yes:  Go to  3.

   No:  Go to  5.

3. CHECK HARNESS (OPEN CIRCUIT). 
   1. Disconnect the steering lock control module connector.
   2. Using a tester, measure the resistance between the steering lock control module connector and chassis ground.

      Connector & terminal 

      (B424) No. 1 - Chassis ground:

      Is the resistance less than 1 Ω?

      Yes:  Go to  4.

      No:  Repair or replace the open circuit of harness.

4. CHECK HARNESS. 
   1. Connect the steering lock control module connector.
   2. Using a tester, measure the voltage between the steering lock control module connector terminals.

      Connector & terminal 

      (B424) No. 6 (+) - (B424) No. 1 (-):

      Is the voltage 11 - 14 V with IG ON?

      Is the voltage less than 1 V with IG OFF?

      Yes:  Replace the steering lock control module. Refer to SECURITY AND LOCKS>STEERING LOCK control module .

      No:  Check the DC power supply circuit.

5. CHECK DTC. 

   Read DTCs of «Keyless Access with Push Button Start» using the Subaru Select Monitor. Refer to KEYLESS ACCESS WITH PUSH BUTTON START SYSTEM (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC B2271 displayed? (Current malfunction)

   Yes:  Perform the diagnosis of DTC B2271. Refer to KEYLESS ACCESS WITH PUSH BUTTON START SYSTEM (DIAGNOSTICS)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC B2271 IGN RELAY CONTROL CIRCUIT .

   No:  Replace the keyless access control module. Refer to SECURITY AND LOCKS>KEYLESS ACCESS control module .