ENTRY AND START SYSTEM > Engine does not Start

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DESCRIPTION


ENGINE START SYSTEM OPERATION

  1. 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.

  2. The certification ECU and other ECUs perform key verification via the LIN communication line.

  3. The power source control ECU activates the ACC relay.

  4. The power source control ECU activates the IG1, IG2, and ST CUT relays. The engine switch indicator light illuminates green.

  5. The certification ECU outputs a steering UNLOCK signal. The signal is sent to the steering lock ECU via the power source control ECU.

  6. The power source control ECU sends an engine start request signal to the ECM.

  7. The ECM and power source control ECU activate the ST relay.

  8. The ECM sends an ACC relay cut signal to the power source control ECU.

  9. The power source control ECU deactivates the ACC relay until the ECU detects an engine start request.

  10. 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.

    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


A110088E01


WIRING DIAGRAM

See CRANKING HOLDING FUNCTION CIRCUIT (Click here).

INSPECTION PROCEDURE

1.CHECK FOR DTC

  1. Delete the DTCs.

    HINT:
    After all DTCs are cleared, check if the trouble occurs again 5 seconds after the engine switch is turned on (IG).

  1. Check for DTCs again.

    OK:
    No DTC is output.



NG
GO TO DTC CHART
OK


2.CHECK BASIC FUNCTION

  1. When there is fuel in the fuel tank, the key is inside the vehicle and the shift lever is on P, check that depressing the brake pedal causes the engine to start.

    OK:
    Engine starts.



NG
Go to step 3
OK

END 

3.CHECK SWITCH CONDITION

  1. When the key is inside the vehicle and the shift lever is on P, check that depressing the brake pedal while pressing the engine switch causes the power source mode to change as follows.

    OK:
    off → on (ACC) → on (IG) → off



NG
GO TO POWER SOURCE MODE DOES NOT CHANGE
OK


4.CHECK BASIC FUNCTION

  1. When there is fuel in the fuel tank, the key is inside the vehicle and the shift lever is on P, check that depressing the brake pedal and pressing the engine switch cranks the engine.

    OK:
    Engine cranks.



NG
Go to step 5
OK

GO TO ENGINE IMMOBILISER SYSTEM 

5.CHECK STEERING LOCK SYSTEM

  1. When the engine switch is on (ACC), check that the steering lock can be released.

    OK:
    Steering lock can be released.



NG
GO TO STEERING LOCK SYSTEM
OK


6.CHECK WIRE HARNESS (POWER SOURCE CONTROL ECU - PNP SWITCH)

A109258E02

  1. Disconnect the L73 ECU connector.

  1. Disconnect the E25 switch connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Specified Condition
    L73-17 (STR1) - E25-9
    		Below 1 Ω
    L73-17 (STR1) or E25-9 - Body ground
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


7.CHECK WIRE HARNESS (ENGINE ROOM NO. 2 RELAY BLOCK - POWER SOURCE CONTROL ECU)
A109244E05

  1. Remove the ST CUT relay from the engine room No. 2 relay block.

  1. Disconnect the L73 ECU connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Specified Condition
    Engine room No. 2 relay block ST CUT relay terminal 3 - L73-15 (STR2)
    		Below 1 Ω
    Engine room No. 2 relay block ST CUT relay terminal 3 or L73-15 (STR2) - Body ground
    		10 kΩ or higher

    Standard resistance:
    Tester Connection
    		Specified Condition
    Engine room No. 2 relay block ST CUT relay terminal 2- L73-35 (IG2D)
    		Below 1 Ω
    Engine room No. 2 relay block ST CUT relay terminal 2 or L73-35 (IG2D) - Body ground
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


8.CHECK POWER SOURCE CONTROL ECU

B075721E03

  1. Reconnect the L73 ECU connector.

  1. Measure the voltage of the ECU.

    Standard voltage:
    Tester Connection
    		Condition
    		Specified Condition
    L73-39 (STSW) - Body ground
    		Engine switch on (IG)
    		10 to 14 V



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

GO TO SFI SYSTEM