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Home >> Subaru >> 2021 >> Ascent Base >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Anti-Theft Systems >> Security And Locks - Keyless Access (W/Push Button Start) (Diagnostics) >> Diagnostic Procedure with Diagnostic Trouble Code (DTC) >> DTC B2784: Antenna Circuit (Push Engine Switch)

DTC B2784: Antenna Circuit (Push Engine Switch)

DTC detecting condition: 

When the keyless access control module receives the data of Abnormal antenna coil from transponder key amplifier via transponder communication (communication between keyless access control module - push button ignition SW) during initial operation of transponder collation.

Trouble symptom: 

The keyless access function may not be operable.

Wiring diagram: 

Immobilizer system Ref. to WIRING SYSTEM>Immobilizer System>WIRING DIAGRAM .

G11264307Courtesy of SUBARU OF AMERICA, INC.
CAUTION:
  • For replacement procedure of keyless access control module, refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume.
  • Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to KEYLESS ACCESS WITH PUSH BUTTON START (DIAGNOSTICS)>General Description>CAUTION .
  1. CHECK STEERING LOCK CONTROL MODULE  .
    1. Disconnect the push button ignition switch connector.
    2. Disconnect the keyless access control module connector.
    3. Using a tester, measure the resistance between the push button ignition switch connector the keyless access control module connector.

      Connector & terminal 

      (i150) No. 9 - (i241) No. 19:

      (i150) No. 10 - (i241) No. 22:

      (i150) No. 14 - (i241) No. 21:

      (i150) No. 8 - (i241) No. 24:

    Is the resistance less than 1 Ω?

    Yes  : Go to  2.

    No  : Repair or replace the open circuit of harness.

  2. CHECK HARNESS (GROUND SHORT CIRCUIT)  .

    Using a tester, measure the resistance between the push button ignition switch connector and chassis ground.

    Connector & terminal 

    (i150) No. 14 - Chassis ground:

    (i150) No. 9 - Chassis ground:

    (i150) No. 10 - Chassis ground:

    Is the resistance 10 kΩ or more?

    Yes  : Go to  3.

    No  : Repair or replace the short circuit of the harness.

  3. CHECK PUSH BUTTON IGNITION SWITCH  .
    1. Replace the push button ignition switch. Ref. to SECURITY AND LOCKS>PUSH BUTTON IGNITION SWITCH .
    2. Using the Subaru Select Monitor, perform the clear memory of [Keyless Access with Push Button Start]. Ref. to COMMON (diag)>CLEAR MEMORY .
    3. Read the DTC of [Keyless Access with Push Button Start] using the Subaru Select Monitor. Ref. to KEYLESS ACCESS WITH PUSH BUTTON START (DIAGNOSTICS)>Diagnostic Trouble Code (DTC) .

    Is DTC B2784 displayed? (Current malfunction)

    Yes  : Replace the keyless access control module. Ref. to SECURITY AND LOCKS>KEYLESS ACCESS CONTROL MODULE

    No  : Malfunction occurred in the push button ignition switch.