B2278

2AR-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 main body ECU and the engine switch; or 2) either of the switches inside the engine switch is malfunctioning.

HINT
When the main body ECU is replaced with a new one and the negative (-) battery terminal is connected, the power source mode becomes the IG-ON mode. When the battery is removed and reinstalled, the power source mode that was selected when the battery was removed is restored.

After the main body ECU is replaced, perform the registration procedures for the engine immobiliser system Engine Immobiliser System (W/ Smart Key System).





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM (START SWITCH)

(a) Connect Techstream to the DLC3.

(b) Check the DATA LIST for proper functioning of the start switch.

HINT
When using Techstream with the engine switch off, turn on and off any of the door courtesy light switches repeatedly at 1.5 second intervals or less until communication between the tester and vehicle starts.

Main Body:





OK:

ON (engine switch on (IG)) and OFF (engine switch off) appear on the screen.

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

2. CHECK ENGINE SWITCH CONDITION

(a) Check the power source mode change.

(1) When the key is inside the vehicle and the shift lever is in the P position, check that pressing the engine switch causes the power source mode to change as follows:

OK:

off -> on (ACC) -> on (IG) -> off

HINT
* If power mode does not change to ON (IG and ACC) Power Source Mode Does Not Change To ON (IG and ACC).
* If power mode does not change to ON (IG) Power Source Mode Does Not Change To ON (IG).
* If power mode does not change to ON (ACC) Power Source Mode Does Not Change To ON (ACC).

NG -- GO TO OTHER PROBLEM

OK -- END

3. INSPECT ENGINE SWITCH

(a) Remove the engine switch.





(b) Disconnect the switch connector.

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

Standard resistance:





HINT
This switch is a momentary type switch.

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

4. CHECK WIRE HARNESS (ENGINE SWITCH - MAIN BODY ECU AND BODY GROUND)

(a) Disconnect the E7 ECU connector.





(b) Disconnect the E52 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 -- REPLACE MAIN BODY ECU