DTC B2A09: I-Call Button Circuit

Diagnosis start condition:

When ignition switch is ON.

DTC detecting condition:

The following conditions occur for at least 50 ms.

i-button impedance is more than 10 kΩ.
i-button is stuck for at least 60 seconds.

Trouble symptom:

i-Call function cannot be used.
RED LED illuminates.

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 .

Wiring diagram:

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

Courtesy of SUBARU OF AMERICA, INC.

CHECK DTC .
Read the DTC of [Telematics] using the Subaru Select Monitor. Ref. to TELEMATICS SYSTEM (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

Is DTC B2A09 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.

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 telematics button connector.
3. Disconnect the DCM connector.
4. Measure the resistance between the DCM connector and telematics button connector and between the telematics button connector and chassis ground.
  Connector & terminal
  
  (i105) No. 4 - (Rf32) No. 3:
  
  (Rf32) No. 1 - Chassis ground:
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) .
Measure the resistance between DCM connector and chassis ground.

Connector & terminal

(i105) No. 4 - 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. Measure the voltage between the DCM connector and chassis ground and between the telematics button connector and chassis ground.
  Connector & terminal
  
  (i105) No. 4 (+) - Chassis ground (-):
  
  (Rf32) No. 1 (+) - Chassis ground (-):
Is the voltage less than 1 V?

Yes: Go to 5.

No: Repair or replace the short circuit of the harness.
CHECK THE I-BUTTON .
1. Turn the ignition switch to OFF.
2. Measure the resistance of the i-button unit.
  Terminals
  
  No. 3 - No. 1:
Is the resistance 1 Ω or less when i-button is ON, and 1.5 - 1.7 kΩ when i-button is OFF?

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

No: Replace the telematics button. Ref. to ENTERTAINMENT & MONITORING>SWITCHES AND HARNESS .