B278A

THEFT DETERRENT / KEYLESS ENTRY: ENGINE IMMOBILISER 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 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 Start / Stop Switch.

NEXT -- Continue to next step.

3. CLEAR DTC

(a) Clear the DTCs Engine Immobiliser System.

NEXT -- Continue to next step.

4. CHECK FOR DTC

(a) Check for DTCs Engine Immobiliser System.

OK:

DTC B278A is not output.

NG -- REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) Removal

OK -- END (ENGINE SWITCH IS DEFECTIVE)