B2784

ENGINE IMMOBILISER: ENGINE IMMOBILISER SYSTEM: B2784: Antenna Coil Open / Short

DTC B2784 - Antenna Coil Open / Short

DESCRIPTION

The antenna coil receives key code signals from the transponder chip in the key grip. The coil is built into the transponder key amplifier, which amplifies the key code signals and outputs the signals to the transponder key ECU.
This DTC is output when there is an open or short malfunction in the antenna coil.





WIRING DIAGRAM





INSPECTION PROCEDURE

HINT: When the transponder key ECU is replaced, reregister the ECU - ECM communication ID (Engine Immobiliser System).

PROCEDURE

1. CLEAR DTC
(a) Clear the DTC (Engine Immobilizer System).
NEXT -- Continue to next step.
2. CHECK FOR DTC
(a) Check for DTC (Engine Immobilizer System).
OK:
DTC B2784 is not output.
NG -- READ VALUE USING TECHSTREAM (ANTENNA COIL)
OK -- USE SIMULATION METHOD TO CHECK
3. READ VALUE USING TECHSTREAM (ANTENNA COIL)
(a) Use the Data List to check if the transponder key coil is functioning properly.
OK:
Normal (Antenna coil is normal) appears on the screen.

Immobiliser





NG -- CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - TRANSPONDER KEY AMPLIFIER)
OK -- REPLACE TRANSPONDER KEY ECU
4. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - TRANSPONDER KEY AMPLIFIER)





(a) Disconnect the J26 ECU connector.
(b) Disconnect the J20 amplifier connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
5. REPLACE TRANSPONDER KEY AMPLIFIER
(a) Temporarily replace the transponder key amplifier with a new or normally functioning one (Removal).
NEXT -- Continue to next step.
6. CLEAR DTC
(a) Clear the DTC (Engine Immobilizer System).
NEXT -- Continue to next step.
7. CHECK FOR DTC
(a) Check for DTC (Engine Immobilizer System).
OK:
DTC B2784 is not output.
NG -- REPLACE TRANSPONDER KEY ECU
OK -- END (TRANSPONDER KEY AMPLIFIER IS DEFECTIVE)