1Nz-Fe Engine Control. Sfi System (For Hatchback) Starter Signal Circuit

While the engine is being cranked, current flows from terminal ST2 of the ignition switch to the park/neutral position switch assembly and also flows to terminal STA of the ECM (STA Signal).

WIRING DIAGRAM

Refer to DTC P0617 (YARIS_NCP93 RM000000TA00XIX_05.html).

INSPECTION PROCEDURE

NOTICE:

Inspect the fuses for circuits related to this system before performing the following inspection procedure.
After turning ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work (YARIS_NCP93 RM00000482L007X.html).

1.CHECK WHETHER ENGINE CAN BE CRANKED

Check if engine can be cranked.
Result
Result
Proceed to
Engine cannot be cranked
A
Engine can be cranked
B

Go to step 13

A

2.READ VALUE USING TECHSTREAM (STARTER SIGNAL)

Connect the Techstream to the DLC3.

Turn the ignition switch to ON.

Turn the Techstream on.

Enter the following menus: Powertrain / Engine and ECT / Data List / Starter Signal.

Check the result when the ignition switch is turned ON and the engine starts.

OK:

Ignition Switch Position	Techstream Display (Starter Signal)
ON	OFF
START	ON

Result
Result	Proceed to
Outside standard range (for manual transaxle)	A
Outside standard range (for automatic transaxle)	B
Within standard range (for manual transaxle)	C
Within standard range (for automatic transaxle)	D

Go to step 7

Go to step 6

Go to step 10

A

3.INSPECT CLUTCH START SWITCH ASSEMBLY

Inspect the clutch start switch assembly (YARIS_NCP93 RM000001B3B010X_01_0001.html).

REPLACE CLUTCH START SWITCH ASSEMBLY (YARIS_NCP93 RM000001B3D00YX.html)

OK

4.INSPECT IGNITION SWITCH

Inspect the ignition switch (YARIS_NCP93 RM000000X2S02EX.html).

REPLACE IGNITION SWITCH (YARIS_NCP93 RM000000WC7027X.html)

OK

5.CHECK HARNESS AND CONNECTOR (IGNITION SWITCH - CLUTCH START SWITCH ASSEMBLY)

Disconnect the ignition switch connector.

Disconnect the clutch start switch assembly connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
D109-7 (ST2) - A66-2	Always	Below 1 Ω
D109-7 (ST2) - C51-63 (NSW)	Always	Below 1 Ω
D109-7 (ST2) or A66-2 - Body ground	Always	10 kΩ or higher
D109-7 (ST2) or C51-63 (NSW) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

6.CHECK HARNESS AND CONNECTOR (CLUTCH START SWITCH ASSEMBLY -ECM - ST RELAY)

Remove the ST relay from the engine room relay block.

Disconnect the ECM connector.

Disconnect the clutch start switch assembly connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
2 (ST relay holder) - A72-22 (STA)	Always	Below 1 Ω
2 (ST relay holder) - A66-1	Always	Below 1 Ω
A72-22 (STA) or A66-1 - Body ground	Always	10 kΩ or higher

Result
Result	Proceed to
Outside standard range	A
Normal standard range	B

Go to step 11

REPAIR OR REPLACE HARNESS OR CONNECTOR

7.INSPECT PARK/NEUTRAL POSITION SWITCH ASSEMBLY

Inspect the park/neutral position switch assembly (YARIS_NCP93 RM00000191B033X.html).

REPLACE PARK/NEUTRAL POSITION SWITCH ASSEMBLY (YARIS_NCP93 RM00000191D03AX.html)

OK

8.INSPECT IGNITION SWITCH

Inspect the ignition switch (YARIS_NCP93 RM000000X2S02EX.html).

REPLACE IGNITION SWITCH (YARIS_NCP93 RM000000WC7027X.html)

OK

9.CHECK HARNESS AND CONNECTOR (IGNITION SWITCH - PARK/NEUTRAL POSITION SWITCH)

Disconnect the ignition switch connector.

Disconnect the park/neutral position switch assembly connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
D109-7 (ST2) - C67-4	Always	Below 1 Ω
D109-7 (ST2) - C51-63 (NSW)	Always	Below 1 Ω
D109-7 (ST2) or C67-4 - Body ground	Always	10 kΩ or higher
D109-7 (ST2) or C51-63 (NSW) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

10.CHECK HARNESS AND CONNECTOR (PARK/NEUTRAL POSITION SWITCH ASSEMBLY - ECM - ST RELAY)

Remove the ST relay from the engine room relay block.

Disconnect the ECM connector.

Disconnect the park/neutral position switch assembly connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
2 (ST relay holder) - A72-22 (STA)	Always	Below 1 Ω
2 (ST relay holder) - C67-5	Always	Below 1 Ω
A72-22 (STA) or C67-5 - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

11.INSPECT BATTERY

Check that the battery is not depleted.

OK:: Battery is not depleted.

REPLACE BATTERY

OK

12.CHECK BATTERY TERMINAL

Check that the battery terminals are not loose or corroded.
OK:
Battery terminals are not loose or corroded.

REPAIR OR REPLACE BATTERY TERMINAL

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE (YARIS_NCP93 RM000000PDG0L6X.html)

13.READ VALUE USING TECHSTREAM (STARTER SIGNAL)

Connect the Techstream to the DLC3.

Turn the ignition switch to ON.

Turn the Techstream on.

Enter the following menus: Powertrain / Engine and ECT / Data List / Starter Signal.

Check the result when the ignition switch is turned ON and the engine starts.
OK:
Ignition Switch Position
Techstream Display
(Starter Signal)
ON
OFF
START
ON

Go to step 14

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE (YARIS_NCP93 RM000000PDG0L6X.html)

14.CHECK HARNESS AND CONNECTOR (ECM - ST RELAY)

Remove the ST relay from the engine room relay block.

Disconnect the ECM connector.

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

Standard Resistance:

Tester Connection
Condition
Specified Condition
A72-22 (STA) - 2 (ST relay holder)
Always
Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE (YARIS_NCP93 RM000000PDG0L6X.html)

Result	Proceed to
Engine cannot be cranked	A
Engine can be cranked	B