Code No.B240D Front antenna(indoor) open

caution When replacing the ECU, always check that the communication circuit is normal.




  • Malfunction of the interior transmitter antenna assembly (front)
  • Malfunction of the KOS-ECU
  • Damaged wiring harness and connectors


STEP 1. Connector check: D-123 Interior transmitter antenna assembly (front) connector, C-104 KOS-ECU connector

Q. Is the check result normal?

STEP 2. Check the wiring harness between the D-123 interior transmitter antenna assembly (front) connector terminal Nos. 1, 2, 3 and the C-104 KOS-ECU connector terminal Nos. 40, 16, 6.

note Prior to the wiring harness inspection, check intermediate connector C-22, and repair if necessary.

Q. Is the check result normal?

STEP 3. Keyless operation system communication test

Antennas to be checked
    front antenna (interior)
OK: Normal is displayed.

Q. Is the check result normal?

STEP 4. Check whether the diagnosis code is reset.

(1)Erase the diagnosis code.
(2)Turn the ignition switch from the LOCK (OFF) position to the ON position.
(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?