DTC B2256: Data Communication Module Communication Open

DTC detecting condition: 

• Detected when a DCM that operates properly is not connected via USB.
• Detected when the DCM is not connected via USB.

Trouble symptom: 

DCM linkage function cannot be used.

1. CHECK DTC  .
   1. Using the Subaru Select Monitor, perform the clear memory of [Cockpit Control]. Refer to COMMON (DIAG)>CLEAR MEMORY .
   2. Turn the ignition switch OFF → ON.
   3. Read the DTC of [Cockpit Control] using the Subaru Select Monitor. Refer to COCKPIT CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC B2256 displayed? (Current malfunction)

   Yes  : Go to  2.

   No  : 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.
2. CHECK CONNECTOR  .

   Check the harness between the cockpit control module connector and DCM.

   Is the check result OK?

   Yes  : Go to  3.

   No  : Repair the harness or replace the components.

3. CHECK DCM  .

   Perform the inspection according to the diagnosis for telematics system. Refer to TELEMATICS SYSTEM (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .

   Is the check result OK?

   Yes  : Replace the cockpit control module. Refer to ENTERTAINMENT & MONITORING>COCKPIT DISPLAY .

   No  : Replace the DCM. Refer to ENTERTAINMENT & MONITORING>DATA COMMUNICATION MODULE .