Engine does not Start: Description

ENGINE START SYSTEM OPERATION

If the engine switch is pressed with the shift lever in P or N and the brake pedal depressed, the power source control ECU determines that it is an engine start request.
The certification ECU and other ECUs perform key verification via the LIN communication line.
The power source control ECU activates the ACC relay.
The power source control ECU activates the IG1, IG2, and ST CUT relays. The engine switch indicator light illuminates green.
The certification ECU outputs a steering UNLOCK signal. The signal is sent to the steering lock ECU via the power source control ECU.
The power source control ECU sends an engine start request signal to the ECM.
The ECM and power source control ECU activate the ST relay.
The ECM sends an ACC relay cut signal to the power source control ECU.
The power source control ECU deactivates the ACC relay until the ECU detects an engine start request.
When engine revolution speed reaches 800 rpm, the power source control ECU determines that the engine has been started. The ECU reactivates the ACC relay and turns off the engine switch indicator light.

SIGNALS REFERENCE

Symbols of power source control ECU	Signals
STP	Stop light switch ON signal
SSW1/SSW2	Engine switch ON signal
ACCD	ACC relay operation signal
IG2D	IG2 relay operation signal
STR2	ST relay operation signal
STR1	Park/neutral position switch signal
TACH	Engine start detection signal
STSW	Starter activation request signal
CTSW	Start assist signal

Fig 1: [Smart Access System With Push-Button Start System Diagram]