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Home >> Subaru >> 2023 >> Ascent Limited >> Repair and Diagnosis >> Electrical >> Gauges >> Instrumentation System (Diagnostics) >> Diagnostic Procedure with Diagnostic Trouble Code (DTC) >> DTC B1502: Warning Box Communication Malfunction

DTC B1502: Warning Box Communication Malfunction

DTC detecting condition: 

Communication failure between the combination meter and the center information display

Trouble symptom: 

Malfunction of the warning light inside the center information display

Wiring diagram: 

Combination meter system Ref. to WIRING SYSTEM>COMBINATION METER SYSTEM>WIRING DIAGRAM .

G16447378Courtesy of SUBARU OF AMERICA, INC.
CAUTION: Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to COMBINATION METER (DIAGNOSTICS)>GENERAL DESCRIPTION>CAUTION .
  1. CHECK POWER SUPPLY CIRCUIT  .

    Turn the ignition switch to ON, and make sure that the combination meter operates properly.

    Is the check result OK?

    Yes:  Go to  2.

    No:  Check the combination meter power supply circuit.

  2. CHECK DTC  .

    Read the DTC of [Combination Meter] using the Subaru Select Monitor. Ref. to COMBINATION METER (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

    Is DTC B1502 displayed? (Current code)

    Yes:  Go to  3.

    No:  Go to  4.

  3. CHECK COMMUNICATION CIRCUIT (HARNESS) (OPEN CIRCUIT)  .
    1. Turn the ignition switch to OFF.
    2. Disconnect the combination meter connector.
    3. Disconnect the cockpit control module connector.
    4. Check the resistance between the combination meter connector and the cockpit control module connector.

      Connector & terminal 

      (i10) No. 12 - (i380) No. 5:

    Is the resistance less than 10 Ω?

    Yes:  Replace the hazard switch assembly. Ref. to LIGHTING SYSTEM>HAZARD SWITCH .

    No:  Repair the open circuit of harness between the combination meter connector and cockpit control module connector.

  4. CHECK CONNECTOR  .
    1. Turn the ignition switch to OFF.
    2. Disconnect the combination meter connector.
    3. Disconnect the cockpit control module connector.

    Is there any fault in the connector?

    Yes:  Repair or replace the connector.

    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.