DTC B2256: Data Communication Module Communication Open

WARNING: This page is about a different car, the 2022 Subaru WRX. However, it is still accessible from the selected car via links, so may be relevant.

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.

CAUTION:

Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to COCKPIT CONTROL (DIAGNOSTICS)>GENERAL DESCRIPTION>CAUTION

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 code)

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