B278A

THEFT DETERRENT / KEYLESS ENTRY: ENGINE IMMOBILISER SYSTEM: B278A: Short to GND in Immobiliser System Power Source Circuit

DTC B278A - Short to GND in Immobiliser System Power Source Circuit

DESCRIPTION

This DTC is stored when the engine switch power source supply line is open or shorted.






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

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





(a) Disconnect the E29 ECU connector.
(b) Disconnect the E18 switch 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.
2. REPLACE ENGINE SWITCH
(a) Temporarily replace the engine switch with a new one.
NEXT -- Continue to next step.
3. CLEAR DTC
(a) Clear the DTCs. Engine Immobilizer System
NEXT -- Continue to next step.
4. CHECK FOR DTC
(a) Check for DTCs. Engine Immobilizer System
OK:
DTC B278A is not output.
NG -- REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)
OK -- END (ENGINE SWITCH IS DEFECTIVE)