DTC B2786: Steering Lock Control Module Communication

DTC detecting condition:

When communication between keyless access Control Module and steering lock Control Module is interrupted for a set amount of time.

Trouble symptom:

The steering lock cannot be released.

CAUTION: For replacement procedure of keyless access Control Module and steering lock Control Module, refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume.

Wiring diagram:

NOTE: For the coupling connector, refer to "WIRING SYSTEM".

Keyless access with push button start system Ref. to WIRING DIAGRAM , Keyless Access With Push Button Start System.

Fig 1: Steering Lock Control Module Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

Step	Check	Yes	No
1 CHECK DTC. Read the DTC using the Subaru Select Monitor. Ref. to READ DIAGNOSTIC TROUBLE CODE (DTC)	Are DTCs other than DTC B2786 displayed?	Perform the diagnosis of DTCs other than B2786.	Go to step 2
2 CHECK HARNESS (OPEN CIRCUIT). Disconnect the keyless access Control Module connector. Disconnect the steering lock Control Module connector. Using the tester, measure the resistance between terminals. Connector & terminal (i241) No. 13 - (i47) No. 5:	Is the resistance less than 1 Ω?	Go to step 3	Repair or replace the open circuit of harness.
3 CHECK HARNESS (GROUND SHORT CIRCUIT). Using a tester, measure the resistance between the keyless access Control Module and chassis ground. Connector & terminal (i241) No. 13 - Chassis ground:	Is the resistance 10 kΩ or more?	Go to step 4	Repair or replace the short circuit of the harness.
4 CHECK HARNESS (OPEN CIRCUIT). 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?	Go to step 5	Repair or replace the open circuit of harness.
5 CHECK HARNESS. Turn the ignition switch to ON. Using a tester, measure the voltage between the steering lock Control Module connector and chassis ground. Connector & terminal (i47) No. 6 (+) - Chassis ground (-): (i47) No. 7 (+) - Chassis ground (-):	Is the voltage 11 - 14 V?	Go to step 6	Repair or replace the faulty portion of the power supply circuit.
6 CHECK STEERING LOCK Control Module. Turn the ignition switch to ON. Using the Subaru Select Monitor, clear the memory. Ref. to CLEAR MEMORY MODE Read the DTC using the Subaru Select Monitor. Ref. to READ DIAGNOSTIC TROUBLE CODE (DTC)	Is DTC B2785 displayed?	Replace the keyless access Control Module. Ref. to KEYLESS ACCESS CONTROL MODULE	Go to step 7
7 CHECK STEERING LOCK Control Module. Turn the ignition switch to ON. Using the Subaru Select Monitor, clear the memory. Ref. to CLEAR MEMORY MODE Read the DTC using the Subaru Select Monitor. Ref. to READ DIAGNOSTIC TROUBLE CODE (DTC)	Is DTC B2786 displayed?	Replace the steering lock Control Module. Ref. to STEERING LOCK CONTROL MODULE	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.