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

DTC detecting condition: 

When mismatch occurs in the IG1 input of the steering lock Control Module for both LIN communication line input (IG1 input value of keyless access Control Module) and solid line input.

Trouble symptom: 

The steering lock cannot be released.

Wiring diagram: 

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

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK FUSE  .

   Check the fuse. Ref. to SECURITY AND LOCKS>RELAY AND FUSE .

   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 data monitor of [Keyless Access with Push Button Start]. Ref. to KEYLESS ACCESS WITH PUSH BUTTON START(DIAGNOSTICS)>Data Monitor .

   • [IGN SW]

   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. Ref. to SECURITY AND LOCKS>Steering Lock Control Module>REMOVAL .

   No: Check the DC power supply circuit.

5. CHECK DTC  .

   Read the DTC using Subaru Select Monitor. Ref. to KEYLESS ACCESS WITH PUSH BUTTON START(DIAGNOSTICS)>Diagnostic Trouble Code (DTC) .

   Is DTC B2271 displayed?

   Yes: Perform the diagnosis of DTC B2271. Ref. to KEYLESS ACCESS WITH PUSH BUTTON START(DIAGNOSTICS)>Diagnostic Procedure with Diagnostic Trouble Code (DTC)>DTC B2271 IGN RELAY CONTROL CIRCUIT .

   No: Replace the keyless access Control Module. Ref. to SECURITY AND LOCKS>Keyless Access Control Module>REMOVAL .