DTC B2255: USB2(Data Communication Module) Faults

DTC detecting condition:

Detected when there is an open circuit in USB2 (Data Communication Module).

Trouble symptom:

Communication between audio or navigation unit and Data Communication Module is impossible.

Wiring diagram:

Navigation system Ref. to WIRING SYSTEM (IMPREZA MODEL)>NAVIGATION SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (EXCEPT FOR HEV))>NAVIGATION SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (HEV))>NAVIGATION SYSTEM>WIRING DIAGRAM .

Audio system Ref. to WIRING SYSTEM (IMPREZA MODEL)>AUDIO SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (EXCEPT FOR HEV))>AUDIO SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (HEV))>AUDIO SYSTEM>WIRING DIAGRAM .

Model without navigation system

Courtesy of SUBARU OF AMERICA, INC.
Model with navigation system

Courtesy of SUBARU OF AMERICA, INC.

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

CHECK DTC .
1. Turn the ignition switch to ON.
2. Using the Subaru Select Monitor, perform the clear memory of [Infotainment]. Ref. to COMMON (DIAG)>CLEAR MEMORY .
3. Turn the ignition switch OFF → ON.
4. Read the DTC of [Infotainment] using the Subaru Select Monitor. Ref. to INFOTAINMENT (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
  Is DTC B2255 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.
CHECK HARNESS (OPEN CIRCUIT) .
1. Turn the ignition switch to OFF.
2. Disconnect the audio connector or navigation unit connector.
3. Disconnect the Data Communication Module connector.
4. Using a tester, measure the resistance between audio connector or navigation unit connector and Data Communication Module connector.
  Connector & terminal
  
  (AD63) No. 1 - (AD59) No. 2:
  
  (AD63) No. 2 - (AD59) No. 3:
  
  (AD63) No. 3 - (AD59) No. 1:
  
  (AD63) No. 4 - (AD59) No. 4:
  
  (AD63) Shield connector - (AD59) Shield connector:
  
  Is the resistance 1 Ω or less?
  
  Yes : Go to 3.
  
  No : Repair or replace the open circuit of harness.
CHECK HARNESS (GROUND SHORT CIRCUIT) .
Using the tester, measure the resistance between audio connector or navigation unit connector and chassis ground.

Connector & terminal

(AD63) No. 1 - Chassis ground:

(AD63) No. 2 - Chassis ground:

(AD63) No. 3 - Chassis ground:

(AD63) No. 4 - Chassis ground:

(AD63) Shield connector - Chassis ground:

Is the resistance 1 MΩ or more?

Yes : Go to 4.

No : Repair or replace the short circuit of the harness.
CHECK HARNESS (SHORT CIRCUIT TO POWER SUPPLY) .
1. Turn the ignition switch to ON.
2. Using the tester, measure the voltage between audio connector or navigation unit connector and chassis ground.
  Connector & terminal
  
  (AD63) No. 1 (+) - Chassis ground (-):
  
  (AD63) No. 2 (+) - Chassis ground (-):
  
  (AD63) No. 3 (+) - Chassis ground (-):
  
  (AD63) No. 4 (+) - Chassis ground (-):
  
  (AD63) Shield connector (+) - Chassis ground (-):
  
  Is the voltage less than 1 V?
  
  Yes : Go to 5.
  
  No : Repair or replace the short circuit of the harness.
CHECK DTC .
1. Turn the ignition switch to OFF.
2. Connect the Data Communication Module. Ref. to ENTERTAINMENT & MONITORING>DATA COMMUNICATION MODULE .
3. Turn the ignition switch to ON.
4. Read the DTC of [Infotainment] using the Subaru Select Monitor. Ref. to INFOTAINMENT (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
  Is DTC B2255 displayed? (Current malfunction)
  
  Yes : Replace the audio or navigation unit. Ref. to ENTERTAINMENT & MONITORING>AUDIO . Ref. to ENTERTAINMENT & MONITORING>NAVIGATION BODY .
  
  No : Malfunction occurred in Data Communication Module.