B278A

DOOR LOCK: SMART KEY SYSTEM: B278A: Short to GND in Immobiliser System Power Source Circuit
B278A - Short to GND in Immobiliser System Power Source Circuit

DESCRIPTION

* Operating the engine switch starts the engine or changes the power source status (ACC / IG / OFF / START).

* The engine switch is a momentary type switch which turns on only while the switch is held down. The certification ECU always stores the power source status (OFF / ACC / ON). If the battery has been removed and reinstalled, the power source status maintained before removal is restored.

* The transponder amplifier is built into the engine switch.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK WIRE HARNESS (CERTIFICATION ECU - ENGINE SWITCH)

(a) Disconnect the D39 ECU connector.





(b) Disconnect the D21 switch connector.





(c) Measure the resistance according to the value(s) in the table below.

Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

2. REPLACE ENGINE SWITCH (RECONFIRM DTC)

(a) Replace the engine switch.

(b) Clear the DTC and repeat the procedure to re-check it Door Lock - Smart Key System.

OK:

DTC is not output.

OK -- END (ENGINE SWITCH IS DEFECTIVE)

NG -- REPLACE CERTIFICATION ECU