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]. Ref. to COMMON (DIAGNOSTICS)>CLEAR MEMORY .
   2. Turn the ignition switch OFF → ON.
   3. Read the DTC of [Cockpit Control] using the Subaru Select Monitor. Ref. 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 AND CABLE CONNECTION  .
   1. Turn the ignition switch to OFF.
   2. Check that the cockpit control module and DCM connector are securely connected.

   Is the check result OK?

   Yes:  Go to  3.

   No:  Connect the connector.

3. CHECK CONNECTOR AND CABLE  .

   Visually check the connector, terminal or cable body.

   Is the check result OK?

   Yes:  Go to  4.

   No:  Replace the cable.

4. CHECK DCM  .

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

   Is the check result OK?

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

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