СИСТЕМА SFI VC Output Circuit

DESCRIPTION

The ECM constantly generates a 5 V power source voltage from the battery voltage supplied to the +B, +B2 (BATT) terminals to operate the microprocessor. The ECM also provides this power source voltage to the sensors through the VC output circuit.

When the VC circuit has a short circuit, the microprocessor in the ECM and sensors that are supplied power through the VC circuit are deactivated because power is not supplied from the VC circuit. When the system is in this condition, it will not start.

WIRING DIAGRAM

*a	Throttle Body with Motor Assembly (Throttle Position Sensor)
*b	Accelerator Pedal Sensor Assembly

CAUTION / NOTICE / HINT

PROCEDURE

1. CHECK COMMUNICATION BETWEEN GTS AND ECM

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the engine switch on (IG).

   3. Turn the GTS on.

   4. Check the communication between the GTS and ECM.

      Tech Tips

      It can be checked using the "Engine and ECT" item of the Data List.

      Result
      Result Proceed to Communication is not possible A Communication is possible B

   
   

   B

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

   A

2. CHECK EFI NO. 2 FUSE VOLTAGE

   

   *1	No. 1 Engine Room Relay Block
   *2	EFI NO. 2 Fuse

   
   

   1. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition 1 (EFI NO. 2 fuse) - Body ground Engine switch on (IG) 11 to 14 V

      Tech Tips

      
      

      • Check the fuse with it installed to the No. 1 engine room relay block.

      • If the result is not as specified, since current is not flowing to the +B and +B2 terminals of the ECM, the system may not be started.

      Result
      Proceed to OK NG

   
   

   NG

   GO TO ECM POWER SOURCE CIRCUIT

   OK

3. CHECK CONNECTION BETWEEN GTS AND ECM (THROTTLE POSITION SENSOR)

   
   

   1. Disconnect the throttle body with motor assembly connector.

   2. Turn the engine switch on (IG).

   3. Turn the GTS on.

   4. Check the communication between the GTS and ECM.

      Tech Tips

      It can be checked using the "Engine and ECT" item of the Data List.

      Result
      Result Proceed to Communication is not possible A Communication is possible B

      Tech Tips

      Perform "Inspection After Repair" after replacing the throttle body with motor assembly.

      Click here

   
   

   B

   REPLACE THROTTLE BODY WITH MOTOR ASSEMBLY Click here

   A

4. CHECK CONNECTION BETWEEN GTS AND ECM (ACCELERATOR PEDAL POSITION SENSOR)

   
   

   1. Disconnect the accelerator pedal sensor assembly connector.

   2. Turn the engine switch on (IG).

   3. Turn the GTS on.

   4. Check the communication between the GTS and ECM.

      Tech Tips

      It can be checked using the "Engine and ECT" item of the Data List.

      Result
      Result Proceed to Communication is not possible A Communication is possible B

   
   

   B

   REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY Click here

   A

5. CHECK CONNECTION BETWEEN GTS AND ECM (INTAKE AIR CONTROL VALVE ACTUATOR (FOR TUMBLE CONTROL VALVE))

   
   

   1. Disconnect the intake air control valve actuator (for tumble control valve) connector.

   2. Turn the engine switch on (IG).

   3. Turn the GTS on.

   4. Check the communication between the GTS and ECM.

      Tech Tips

      It can be checked using the "Engine and ECT" item of the Data List.

      Result
      Result Proceed to Communication is not possible A Communication is possible B

   
   

   B

   REPLACE INTAKE AIR CONTROL VALVE ACTUATOR (FOR TUMBLE CONTROL VALVE) Click here

   A

6. CHECK CONNECTION BETWEEN GTS AND ECM (CAMSHAFT POSITION SENSOR FOR INTAKE CAMSHAFT)

   
   

   1. Disconnect the camshaft position sensor (for intake camshaft) connector.

   2. Turn the engine switch on (IG).

   3. Turn the GTS on.

   4. Check the communication between the GTS and ECM.

      Tech Tips

      It can be checked using the "Engine and ECT" item of the Data List.

      Result
      Result Proceed to Communication is not possible A Communication is possible B

   
   

   B

   REPLACE CAMSHAFT POSITION SENSOR (FOR INTAKE CAMSHAFT) Click here

   A

7. CHECK CONNECTION BETWEEN GTS AND ECM (CAMSHAFT POSITION SENSOR FOR EXHAUST CAMSHAFT)

   
   

   1. Disconnect the camshaft position sensor (for exhaust camshaft) connector.

   2. Turn the engine switch on (IG).

   3. Turn the GTS on.

   4. Check the communication between the GTS and ECM.

      Tech Tips

      It can be checked using the "Engine and ECT" item of the Data List.

      Result
      Result Proceed to Communication is not possible A Communication is possible B

   
   

   B

   REPLACE CAMSHAFT POSITION SENSOR (FOR EXHAUST CAMSHAFT) Click here

   A

8. CHECK CONNECTION BETWEEN GTS AND ECM (CRANKSHAFT POSITION SENSOR)

   
   

   1. Disconnect the crankshaft position sensor connector.

   2. Turn the engine switch on (IG).

   3. Turn the GTS on.

   4. Check the communication between the GTS and ECM.

      Tech Tips

      It can be checked using the "Engine and ECT" item of the Data List.

      Result
      Result Proceed to Communication is not possible A Communication is possible B

   
   

   B

   REPLACE CRANKSHAFT POSITION SENSOR Click here

   A

9. CHECK CONNECTION BETWEEN GTS AND ECM (OIL PRESSURE SENSOR)

   
   

   1. Disconnect the oil pressure sensor connector.

   2. Turn the engine switch on (IG).

   3. Turn the GTS on.

   4. Check the communication between the GTS and ECM.

      Tech Tips

      It can be checked using the "Engine and ECT" item of the Data List.

      Result
      Result Proceed to Communication is not possible A Communication is possible B

   
   

   B

   REPLACE OIL PRESSURE SENSOR Click here

   A

10. CHECK HARNESS AND CONNECTOR

    
    

    1. Disconnect the throttle body with motor assembly connector.

    2. Disconnect the accelerator pedal sensor assembly connector.

    3. Disconnect the intake air control valve actuator (for tumble control valve) connector.

    4. Disconnect the camshaft position sensor (for intake camshaft) connector.

    5. Disconnect the camshaft position sensor (for exhaust camshaft) connector.

    6. Disconnect the crankshaft position sensor connector.

    7. Disconnect the oil pressure sensor connector.

    8. Disconnect the ECM connectors.

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

       Standard Resistance

       Tester Connection Condition Specified Condition D1-134 (VCTA) - Body ground and other terminals Always 10 kΩ or higher A53-49 (VCPA) - Body ground and other terminals Always 10 kΩ or higher A53-52 (VCP2) - Body ground and other terminals Always 10 kΩ or higher D1-96 (VCIA) - Body ground and other terminals Always 10 kΩ or higher D1-111 (VCE1) - Body ground and other terminals Always 10 kΩ or higher D1-116 (VCV1) - Body ground and other terminals Always 10 kΩ or higher D1-81 (VCNE) - Body ground and other terminals Always 10 kΩ or higher D1-110 (VCPT) - Body ground and other terminals Always 10 kΩ or higher A53-2 (+B) - 2 (EFI NO.2 fuse) Always Below 1 Ω A53-3 (+B2) - 2 (EFI NO.2 fuse) Always Below 1 Ω A53-2 (+B) - Body ground Always 10 kΩ or higher A53-3 (+B2) - Body ground Always 10 kΩ or higher

       Result
       Proceed to OK NG

    
    

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR