Brand:

Toyota

Model Name:

Yaris NCP90 91 92 93

Manual:

Repair Manual

Section:

1Nz-Fe Engine Control System

Title:

Sfi System

  1. Description

  2. Wiring diagram

  3. Inspection procedure

  4. Read value using intelligent tester (starter signal)

  5. Inspect ecm (stsw voltage)

  6. Inspect ecm (star voltage)

  7. Inspect park / neutral position switch assembly

  8. Check harness and connector (park/neutral position switch - ecm)

  9. Inspect ecm (star voltage)

  10. Inspect clutch start switch

  11. Check harness and connector (clutch start switch - ecm)

  12. Inspect ignition switch

  13. Check harness and connector (ignition switch - park/neutral position switch - ecm)

  14. Check harness and connector (ignition switch - clutch start switch - ecm)

  15. Inspect battery

  16. Check battery terminal

  17. Check harness and connector (pnp switch or clutch start switch - st relay)

SFI SYSTEM > Cranking Holding Function Circuit


​

DESCRIPTION

The cranking holding control system provides a current to the starter when the ECM detects the ignition switch's start signal (STSW). When the ECM judges that the engine has started, the system cuts the current to the starter. When the ECM receives the STSW signal, it turns on the ACC (Accessory) relay, which prevents flickering of the combination meter, clock and audio system. Also, the ECM sends a signal to the ECM's STAR terminal. Then the STAR output signal travels through the Park/Neutral Position (PNP) switch to the ST relay, causing the starter to activate. When the engine is cranking, the starter operation signal is sent to the ECM's STA terminal.

Connect an intelligent tester to the DLC3. Yaris


WIRING DIAGRAM


Connect an intelligent tester to the DLC3. Yaris


INSPECTION PROCEDURE

1.READ VALUE USING INTELLIGENT TESTER (STARTER SIGNAL)

  1. Connect an intelligent tester to the DLC3.

  1. Turn the ignition switch to ON and turn the tester on.

  1. Select the following menu items: Powertrain / Engine and ECT / Data List / Starter Signal.

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

    OK:
    Conditions
    		Starter Signal
    Ignition switch to ON
    		OFF
    Engine start
    		ON


OKnext
Go to step 12
NG
next down

2.INSPECT ECM (STSW VOLTAGE)
Disconnect the A21 ECM connector. Yaris

  1. Disconnect the A21 ECM connector.

  1. Measure the voltage between the terminals of the ECM connector and the body ground while cranking the engine.

    Standard voltage:
    Tester Connections
    		Specified Conditions
    STSW (A21-14) - Body ground
    		9 to 14 V
Result:
Result
Proceed To
Within standard range (A/T)
A
Within standard range (M/T)
B
Outside standard range
C

  1. Reconnect the ECM connector.



Bnext
Go to step 6

Cnext
Go to step 9
A
next down

3.INSPECT ECM (STAR VOLTAGE)
Disconnect the C27 Park/Neutral Position (PNP) switch connector. Yaris

  1. Disconnect the C27 Park/Neutral Position (PNP) switch connector.

  1. Measure the voltage between the terminals of the PNP switch connector and the body ground while cranking the engine.

    Standard voltage:
    Tester Connections
    		Specified Conditions
    B (C27-4) - Body ground
    		9 to 14 V

  1. Reconnect the PNP switch connector.



NGnext
Go to step 10
OK
next down

4.INSPECT PARK / NEUTRAL POSITION SWITCH ASSEMBLY
Disconnect the C27 PNP switch connector. Yaris

  1. Disconnect the C27 PNP switch connector.

  1. Check the resistance between each terminal shown below when the shift lever is moved to each range.

    Standard resistance:
    Shift Position
    		Tester Connections
    		Specified Conditions
    P
    		PL (6) - RB (2)
    		Below 1 Ω
    L (5) - B (4)
    R
    		RL (1) - RB (2)
    N
    		NL (9) - RB (2)
    L (5) - B (4)
    D
    		DL (7) - RB (2)
    2
    		2L (3) - RB (2)
    L
    		LL (8) - RB (2)

  1. Reconnect the PNP switch connector.



NGnext
REPLACE PARK / NEUTRAL POSITION SWITCH (Click here)
OK
next down

5.CHECK HARNESS AND CONNECTOR (PARK/NEUTRAL POSITION SWITCH - ECM)
Disconnect the C27 PNP switch connector. Yaris

  1. Disconnect the C27 PNP switch connector.

  1. Disconnect the A21 ECM connector.

  1. Check the resistance.

    Standard resistance (Check for open):
    Tester Connections
    		Specified Conditions
    L (C27-5) - STA (A21-48)
    		Below 1 Ω
    Standard resistance (Check for short):
    Tester Connections
    		Specified Conditions
    L (C27-5) or STA (A21-48) - Body ground
    		10 kΩ or higher

  1. Reconnect the PNP switch connector.

  1. Reconnect the ECM connector.



NGnext
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
next down
REPLACE ECM (Click here)

6.INSPECT ECM (STAR VOLTAGE)
Disconnect the A16 clutch start switch connector. Yaris

  1. Disconnect the A16 clutch start switch connector.

  1. Measure the voltage between the terminals of the clutch start switch connector and the body ground while cranking the engine.

    Standard voltage:
    Tester Connections
    		Specified Conditions
    B (A16-2) - Body ground
    		9 to 14 V

  1. Reconnect the clutch start switch connector.



NGnext
Go to step 11
OK
next down

7.INSPECT CLUTCH START SWITCH
Disconnect the A16 clutch start switch connector. Yaris

  1. Disconnect the A16 clutch start switch connector.

  1. Check the resistance between the terminals of the clutch start switch.

    Standard resistance:
    Switch Positions
    		Specified Conditions
    Pushed in
    		Below 1 Ω
    Released
    		10 kΩ or higher

  1. Reconnect the clutch start switch connector.



NGnext
REPLACE CLUTCH START SWITCH
OK
next down

8.CHECK HARNESS AND CONNECTOR (CLUTCH START SWITCH - ECM)
Disconnect the A16 clutch start switch connector. Yaris

  1. Disconnect the A16 clutch start switch connector.

  1. Disconnect the A21 ECM connector.

  1. Check the resistance.

    Standard resistance (Check for open):
    Tester Connections
    		Specified Conditions
    L (A16-1) - STA (A21-48)
    		Below 1 Ω
    Standard resistance (Check for short):
    Tester Connections
    		Specified Conditions
    L (A16-1) or STA (A21-48) - Body ground
    		10 kΩ or higher

  1. Reconnect the clutch start switch connector.

  1. Reconnect the ECM connector.



NGnext
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
next down
REPLACE ECM (Click here)

9.INSPECT IGNITION SWITCH
Disconnect the D8 ignition switch connector. Yaris

  1. Disconnect the D8 ignition switch connector.

  1. Check the resistance between the terminals shown below.

    Standard resistance:
    Key Positions
    		Tester Connections
    		Specified Conditions
    LOCK
    		-
    		10 kΩ or higher
    ACC
    		2 - 4
    		Below 1 Ω
    ON
    		1 - 2 - 4
    5 - 6
    START
    		1 - 3 - 4
    5 - 6 - 7

  1. Reconnect the ignition switch connector.



NGnext
REPLACE IGNITION SWITCH (Click here)
OK
next down
REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - IGNITION SWITCH - BATTERY)

10.CHECK HARNESS AND CONNECTOR (IGNITION SWITCH - PARK/NEUTRAL POSITION SWITCH - ECM)
Disconnect the D8 ignition switch connector. Yaris

  1. Disconnect the D8 ignition switch connector.

  1. Disconnect the C27 PNP switch connector.

  1. Disconnect the C20 ECM connector.

  1. Check the resistance.

    Standard resistance (Check for open):
    Tester Connections
    		Specified Conditions
    ST2 (D8-7) - B (C27-4)
    		Below 1 Ω
    STAR (C20-52) - B (C27-4)
    STAR (C20-52) - L (C27-5)
    Standard resistance (Check for short):
    Tester Connections
    		Specified Conditions
    ST2 (D8-7) or B (C27-4) - Body ground
    		10 kΩ or higher
    STAR (C20-52) or B (C27-4) - Body ground
    STAR (C20-52) or L (C27-5) - Body ground

  1. Reconnect the ignition switch connector.

  1. Reconnect the PNP switch connector.

  1. Reconnect the ECM connector.



NGnext
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
next down
REPLACE ECM (Click here)

11.CHECK HARNESS AND CONNECTOR (IGNITION SWITCH - CLUTCH START SWITCH - ECM)
Disconnect the D8 ignition switch connector. Yaris

  1. Disconnect the D8 ignition switch connector.

  1. Disconnect the A16 clutch start switch connector.

  1. Disconnect the C20 ECM connector.

  1. Check the resistance.

    Standard resistance (Check for open):
    Tester Connections
    		Specified Conditions
    ST2 (D8-7) - B (A16-2)
    		Below 1 Ω
    STAR (C20-52) - B (A16-2)
    STAR (C20-52) - L (A16-1)
    Standard resistance (Check for short):
    Tester Connections
    		Specified Conditions
    ST2 (D8-7) or B (A16-2) - Body ground
    		10 kΩ or higher
    STAR (C20-52) or B (A16-2) - Body ground
    STAR (C20-52) or L (A16-1) - Body ground

  1. Reconnect the ignition switch connector.

  1. Reconnect the clutch start switch connector.

  1. Reconnect the ECM connector.



NGnext
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
next down
REPLACE ECM (Click here)

12.INSPECT BATTERY

  1. Check that the battery is not depleted.

    OK:
    Battery is not depleted.


NGnext
REPLACE BATTERY
OK
next down

13.CHECK BATTERY TERMINAL

  1. Check that the battery terminals are not loose or corroded.

    OK:
    Battery terminals are not loose or corroded.


NGnext
REPAIR OR REPLACE BATTERY TERMINAL
OK
next down

14.CHECK HARNESS AND CONNECTOR (PNP SWITCH OR CLUTCH START SWITCH - ST RELAY)
Remove the ST relay from the engine room relay block. Yaris

  1. Remove the ST relay from the engine room relay block.

  1. Disconnect the C27 PNP switch connector (A/T).

  1. Disconnect the A16 clutch start switch connector (M/T).

  1. Check the resistance.

    Standard resistance (Check for open):
    Tester Connections
    		Specified Conditions
    L (C27-5) - ST relay (2)
    		Below 1 Ω
    L (A16-1) - ST relay (2)
    ST relay (1) - Body ground
    Standard resistance (Check for short):
    Tester Connections
    		Specified Conditions
    L (C27-5) or ST relay (2) - Body ground
    		10 kΩ or higher
    L (A16-1) or ST relay (2) - Body ground

  1. Reinstall the ST relay.

  1. Reconnect the PNP switch connector (A/T).

  1. Reconnect the clutch start switch connector (M/T).



NGnext
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
next down
CHECK AND REPLACE STARTER RELAY AND STARTER