B2278

1NZ-FXE STARTING: SMART KEY SYSTEM: B2278: Engine Switch Circuit Malfunction

DTC B2278 - Engine Switch Circuit Malfunction

DESCRIPTION

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






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING DATA LIST (START SWITCH 1 and 2)
(a) Connect Techstream to the DLC3.
(b) Turn the power switch ON (IG) and press Techstream main switch ON.
(c) Read the DATA LIST according to the displays on the tester.

Power source control ECU





OK:
ON (power switches 1 and 2 are ON (IG)) appears on the screen
OK -- REPLACE POWER SOURCE CONTROL ECU
NG -- Continue to next step.

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




(a) Disconnect the P11 power switch connector.
(b) Disconnect the P6 ECU connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






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

3. INSPECT POWER SWITCH




(a) Remove the power switch.
(b) Measure the resistance of the switch.
Standard resistance:






NG -- REPLACE POWER SWITCH
OK -- REPLACE POWER SOURCE CONTROL ECU