B2278

2GR-FE STARTING: SMART KEY SYSTEM: B2278: Engine Switch Circuit Malfunction
B2278 - Engine Switch Circuit Malfunction

DESCRIPTION

This DTC is output when: 1) a malfunction is detected between the power source control ECU and the engine switch; or 2) either of the switches inside the engine switch is malfunctioning.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM

(a) Connect Techstream to the DLC3.

(b) Turn the engine switch on (IG) and press Techstream main switch on.

(c) Read the Data List according to the displays on the tester.

Power source control





OK:

"ON" (engine switch on (IG)) appears on the screen

Result:





C -- INSPECT ENGINE SWITCH

B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

A -- REPLACE POWER SOURCE CONTROL ECU

2. INSPECT ENGINE SWITCH

(a) Disconnect the D21 switch connector.





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

Resistance:





NG -- REPLACE ENGINE SWITCH
OK -- Continue to next step.

3. CHECK WIRE HARNESS (ENGINE SWITCH - POWER SOURCE CONTROL ECU AND BODY GROUND)

(a) Disconnect the D44 ECU connector.





(b) Disconnect the D21 Switch connector.





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

Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ENGINE SWITCH