B278A

ENGINE IMMOBILISER: ENGINE IMMOBILISER SYSTEM (w/ Smart Key System): B278A: Short to GND in Immobiliser System Power Source Circuit
B278A - Short to GND in Immobiliser System Power Source Circuit

DESCRIPTION

This DTC is output when the engine switch power source supply line is open or short.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - ENGINE SWITCH)





(a) Disconnect the E84 ECU connector.

(b) Disconnect the E78 switch connector.

(c) Measure the resistance of the wire harness side connectors.

Standard Resistance:





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

2. REPLACE ENGINE SWITCH

(a) Temporarily replace the engine switch with a new or normally functioning one.

* for 2AR-FE: Removal.

* for 2GR-FE: Removal.

NEXT -- Continue to next step.

3. CHECK FOR DTC

(a) Clear the DTC Engine Immobiliser System (w/ Smart Key System).

(b) Recheck for the DTC.

OK:

B278A is not output.

NG -- REPLACE ECU AGGREGATION BOX (CERTIFICATION ECU) Removal

OK -- END (ENGINE SWITCH IS DEFECTIVE)