DTC B2A04: Mic Circuit

Diagnosis start condition :

When ACC is ON.

DTC detecting condition :

Any of the followings continues for 1 second or more.

MIC impedance is more than 10 KΩ. (Detached MIC, etc.)
MIC impedance is less than 10 Ω. (Short-circuited MIC, etc.)

Trouble symptom :

Call function cannot be used.
RED LED illuminates.

Failure detection pattern :

"Primary" (high-priority diagnosis)

Warning light/indicator light :

Both ON -
GREEN LED ON -
GREEN LED blinks -
RED LED ONO
RED LED blinks -
Both OFF -

Wiring diagram :

Telematics Ref. to WIRING SYSTEM>TELEMATICS SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

CAUTION:

After the DCM is replaced, registrations of CommCheck and immobilizer system are required. Ref. to ENTERTAINMENT & MONITORING>TELEMATICS SYSTEM>OPERATION>REGISTRATION (COMM CHECK) .
Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to TELEMATICS SYSTEM (DIAGNOSTICS)>GENERAL DESCRIPTION>CAUTION .

CHECK DTC .
1. Turn the ignition switch to ON.
2. Read the DTC of [Telematics] using the Subaru Select Monitor. Ref. to TELEMATICS SYSTEM (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
Is DTC B2A04 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 HARNESS (OPEN CIRCUIT) .
1. Turn the ignition switch to OFF.
2. Disconnect the microphone connector.
3. Disconnect the DCM connector.
4. Using a tester, measure the resistance between the DCM connector and microphone connector.
  Connector & terminal
  
  (i106) No. 8 - (Rf11) No. 5 :
  
  (i106) No. 14 - (Rf11) No. 16 :
  
  (i106) No. 6 - (Rf11) No. 7 :
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 a tester, measure the resistance between DCM connector and chassis ground

Connector & terminal

(i106) No. 8 - Chassis ground :

(i106) No. 14 - Chassis ground :

(i106) No. 6 - Chassis ground :

Is the resistance 1 MΩ or more?

Yes : GO TO 4.

No : Repair or replace the short circuit of the harness.
CHECK THE CONNECTOR (SHORT CIRCUIT TO POWER SUPPLY) .
1. Turn the ignition switch to ON.
2. Using a tester, measure the voltage between DCM connector and chassis ground.
  Connector & terminal
  
  (i106) No. 8 (+) - Chassis ground (-) :
  
  (i106) No. 14 (+) - Chassis ground (-) :
  
  (i106) No. 6 (+) - Chassis ground (-) :
Is the voltage less than 1 V?

Yes : GO TO 5.

No : Repair or replace the short circuit of the harness.
CHECK MICROPHONE UNIT .
1. Turn the ignition switch to OFF.
2. Connect all the disconnected connectors.
3. Confirm the microphone voice input. Ref. to COCKPIT CONTROL (DIAGNOSTICS)>DEALERSHIP MODE .
Is the check result OK?

Yes : Replace the DCM. Ref. to ENTERTAINMENT & MONITORING>DATA COMMUNICATION MODULE .

No : Replace the map light. Ref. to LIGHTING SYSTEM>SPOT MAP LIGHT .