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

DTC detecting condition:

When one second elapses while the ignition switch status is not compatible between LIN communication and direct line.

Trouble symptom:

The steering lock cannot be released.

Wiring diagram:

Keyless access with push button start system Ref. to WIRING SYSTEM (IMPREZA MODEL)>KEYLESS ACCESS WITH PUSH BUTTON START SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (EXCEPT FOR HEV))>KEYLESS ACCESS WITH PUSH BUTTON START SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (HEV))>KEYLESS ACCESS WITH PUSH BUTTON START SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

CAUTION:

For replacement procedure of steering lock control module or keyless access control module, refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume.
Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to KEYLESS ACCESS WITH PUSH BUTTON START (DIAGNOSTICS)>GENERAL DESCRIPTION>CAUTION .

CHECK FUSE .
1. Turn the ignition switch to OFF.
2. Check the fuse. Ref. 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.
CHECK DATA MONITOR .
1. Turn the ignition switch to ON.
2. Using the Subaru Select Monitor, check the following items in 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.
CHECK HARNESS (OPEN CIRCUIT) .
1. Turn the ignition switch to OFF.
2. Disconnect the steering lock control module connector.
3. Using a tester, measure the resistance between the steering lock control module connector and chassis ground.
  Connector & terminal
  
  (i47) No. 1 - Chassis ground:
Is the resistance less than 1 Ω?

Yes: Go to 4.

No: Repair or replace the open circuit of harness.
CHECK HARNESS .
1. Connect the steering lock control module connector.
2. Turn the ignition switch to ON.
3. Using a tester, measure the voltage between the steering lock control module connector terminals.
  Connector & terminal
  
  (i47) No. 6 (+) - (i47) 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 .

No: Check the DC power supply circuit.
CHECK DTC .

Read the DTC of [Keyless Access with Push Button Start] using the Subaru Select Monitor. Ref. to KEYLESS ACCESS WITH PUSH BUTTON START (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

Is DTC B2271 displayed? (Current malfunction)

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 .