DTC B2256: Data Communication Module Communication Open [11/2021 - ]: Procedure

1. Using the GTS, perform the clear memory of [Cockpit Control].

   Body Electrical > Cockpit Control > Clear DTCs 

2. Turn the ignition switch OFF → ON.
3. Read the DTC of [Cockpit Control] using the GTS.

   Body Electrical > Cockpit Control > Trouble Codes 

   Is DTC B2256 displayed? (Current malfunction)

   Result	Proceed to
   YES	A
   NO (Use Simulation Method to Check)	B

Result: 

B 

USE SIMULATION METHOD TO CHECK 

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.

HINT: 

In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.

Result: 

A 

See step  2

1. Check the harness between the navigation ECU assembly connector and DCM (telematics transceiver).

   Is the check result OK?

   Result	Proceed to
   YES	A
   NO (Repair the harness or replace the components)	B

Result: 

B 

REPAIR THE HARNESS OR REPLACE THE COMPONENTS 

Result: 

A 

See step  3

1. Perform the inspection according to the diagnosis for telematics system.

   Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2021 - ]

   Is the check result OK?

   Result	Proceed to
   YES (Replace the navigation ECU assembly)	A
   NO (Replace the DCM (telematics transceiver))	B

Result: 

A 

REPLACE NAVIGATION ECU ASSEMBLY. Refer to  REMOVAL [11/2021 - ] 

Result: 

B 

REPLACE THE DCM (TELEMATICS TRANSCEIVER). Refer to  REMOVAL [11/2021 - ]