SFI SYSTEM Starter Signal Circuit

DESCRIPTION

w/o Entry and Start System

• While the engine is being cranked, current flows from terminal ST2 of the ignition switch assembly to the clutch start switch assembly and also flows to terminal STA of the ECM (STA Signal). The ECM uses the STA signal to control the fuel injection and ignition timing when the engine starts.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1. CHECK WHETHER ENGINE CAN BE CRANKED

   
   

   1. Check if the engine can be cranked.

      Result

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

   
   

   B

   READ VALUE USING INTELLIGENT TESTER (STARTER SIGNAL) Click here

   A

2. READ VALUE USING INTELLIGENT TESTER (STARTER SIGNAL)

   
   

   1. Connect the intelligent tester to the DLC3.

   2. Turn the ignition switch to ON.

   3. Turn the tester on.

   4. Enter the following menu items: Powertrain / Engine and ECT / Data List / Starter Signal.

   5. Check the value displayed on the tester when the ignition switch is turned to the ON and START positions.

      OK
      Ignition Switch Position Starter Signal ON OFF START ON

   
   

   NG

   READ VALUE USING INTELLIGENT TESTER (STARTER SIGNAL) Click here

   OK

3. CHECK ST RELAY (POWER SOURCE)

   
   
   1. 

      Text in Illustration

      *1	Engine room relay Block
      *2	ST Relay Holder

      Remove the ST relay from the engine room relay block.

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

      Standard Voltage
      Tester Connection Condition Specified Condition 5 (ST relay holder) - Body ground Always 11 to 14 V

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR (ST RELAY - BATTERY)

   OK

4. CHECK HARNESS AND CONNECTOR (ECM - ST RELAY - BODY GROUND)

   
   

   1. Disconnect the ECM connector.

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

   3. Disconnect the power management control ECU connector.

   4. Disconnect the clutch start switch assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition A71-40 (STA) - 2 (ST relay holder) Always Below 1 Ω 1 (ST relay holder) - Body ground Always Below 1 Ω A71-40 (STA) or 2 (ST relay holder) - Body ground Always 10 kΩ or higher

   
   

   OK

   PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

5. READ VALUE USING INTELLIGENT TESTER (STARTER SIGNAL)

   
   

   1. Disconnect the power management control ECU connector.

   2. Connect the intelligent tester to the DLC3.

   3. Turn the ignition switch to ON.

   4. Turn the tester on.

   5. Enter the following menu items: Powertrain / Engine and ECT / Data List / Starter Signal.

   6. Check the value displayed on the tester when the ignition switch is turned to the ON and START positions.

      OK
      Ignition Switch Position Starter Signal ON OFF START ON

   
   

   OK

   REPLACE POWER MANAGEMENT CONTROL ECU Click here

   NG

6. INSPECT IGNITION SWITCH ASSEMBLY

   
   

   1. Inspect the ignition switch assembly Click here.

   
   

   NG

   REPLACE IGNITION SWITCH ASSEMBLY Click here

   OK

7. INSPECT CLUTCH START SWITCH ASSEMBLY

   
   

   1. Inspect the clutch start switch assembly Click here.

   
   

   NG

   REPLACE CLUTCH START SWITCH ASSEMBLY Click here

   OK

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

   
   

   1. Disconnect the ECM connector.

   2. Disconnect the clutch start switch assembly connector.

   3. Disconnect the ignition switch connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition A71-25 (NSW) - F13-7 (ST2) Always Below 1 Ω A71-25 (NSW) - A39-2 Always Below 1 Ω A71-25 (NSW), A39-2 or F13-7 (ST2) - Body ground Always 10 kΩ or higher

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

9. CHECK HARNESS AND CONNECTOR (ECM - CLUTCH START SWITCH ASSEMBLY - ST RELAY - POWER MANAGEMENT CONTROL ECU)

   
   

   1. Disconnect the ECM connector.

   2. Disconnect the clutch start switch assembly connector.

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

   4. Disconnect the power management control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition A71-40 (STA) - A39-1 Always Below 1 Ω A71-40 (STA) - A52-5 (STA) Always Below 1 Ω A71-40 (STA) - 2 (ST relay holder) Always Below 1 Ω A71-40 (STA), A52-5 (STA), A39-1 or 2 (ST relay holder) - Body ground Always 10 kΩ or higher

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

10. CHECK IGNITION SWITCH ASSEMBLY (POWER SOURCE)

    

    Text in Illustration

    *a	Front view of wire harness connector (to Ignition Switch Assembly)

    
    

    1. Disconnect the ignition switch assembly connector.

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

       Standard Voltage
       Tester Connection Condition Specified Condition F13-5 (AM2) - Body ground Always 11 to 14 V

    
    

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IGNITION SWITCH ASSEMBLY - BATTERY)

11. READ VALUE USING INTELLIGENT TESTER (STARTER SIGNAL)

    
    

    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Enter the following menu items: Powertrain / Engine and ECT / Data List / Starter Signal.

    5. Check the value displayed on the tester when the ignition switch is turned to the ON and START positions.

       OK
       Ignition Switch Position Starter Signal ON OFF START ON

    
    

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    NG

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

    
    

    1. Disconnect the ECM connector.

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

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

       Standard Resistance
       Tester Connection Condition Specified Condition A71-40 (STA) - 2 (ST relay holder) Always Below 1 Ω

    
    

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR