Engine Does Not Start

1UR-FSE STARTING: SMART ACCESS SYSTEM WITH PUSH-BUTTON START: Engine does not Start
- Engine does not Start

DESCRIPTION

1. ENGINE START SYSTEM OPERATION

(a) 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.

(b) The certification ECU and other ECUs perform key verification via the LIN communication line.

(c) The power source control ECU activates the ACC relay.

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

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

(f) The power source control ECU sends an engine start request signal to the ECM.

(g) The ECM and power source control ECU activate the ST relay.

(h) The ECM sends an ACC relay cut signal to the power source control ECU.

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

(j) 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.









WIRING DIAGRAM

See CRANKING HOLDING FUNCTION CIRCUIT Cranking Holding Function Circuit.

INSPECTION PROCEDURE

PROCEDURE

1. CHECK FOR DTC

(a) 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).

(b) Check for DTCs again.

OK:

No DTC is output.

NG -- GO TO DTC CHART
OK -- Continue to next step.

2. CHECK BASIC FUNCTION

(a) 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 -- CHECK SWITCH CONDITION

OK -- END

3. CHECK SWITCH CONDITION

(a) 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 -- Continue to next step.

4. CHECK BASIC FUNCTION

(a) 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 -- CHECK STEERING LOCK SYSTEM

OK -- GO TO ENGINE IMMOBILIZER SYSTEM

5. CHECK STEERING LOCK SYSTEM

(a) 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 -- Continue to next step.

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

(a) Disconnect the K73 ECU connector.





(b) Disconnect the E77 switch 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.

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

(a) Remove the ST CUT relay from the engine room No. 2 relay block.





(b) Disconnect the K73 ECU connector.

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

Standard resistance:





Standard resistance:





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

8. CHECK POWER SOURCE CONTROL ECU





(a) Reconnect the K73 ECU connector.

(b) Measure the voltage of the ECU.

Standard voltage:





NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR

OK -- GO TO SFI SYSTEM