SFI SYSTEM VC Output Circuit

DESCRIPTION

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

When the VC circuit is short-circuited, the microprocessor in the ECM and sensors that are supplied with power through the VC circuit are deactivated because the power is not supplied from the VC circuit. Under this condition, the system does not start up and the MIL does not illuminate even if the system malfunctions.

WIRING DIAGRAM

PROCEDURE

1. CHECK MIL

   
   

   1. Check that the Malfunction Indicator Lamp (MIL) lights up when the engine switch is turned on (IG).

      OK
      MIL lights up.

   
   

   OK

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

   NG

2. CHECK CONNECTION 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.

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

   
   

   B

   GO TO MIL CIRCUIT Click here

   A

3. CHECK MIL (THROTTLE POSITION SENSOR)

   
   

   1. Disconnect the throttle body with motor assembly connector.

   2. Turn the engine switch on (IG).

   3. Check the MIL.

      Result
      Result Proceed to MIL does not illuminate A MIL illuminates 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 MIL (ACCELERATOR PEDAL SENSOR)

   
   

   1. Disconnect the accelerator pedal sensor assembly connector.

   2. Turn the engine switch on (IG).

   3. Check the MIL.

      Result
      Result Proceed to MIL does not illuminate A MIL illuminates B

   
   

   B

   REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY Click here

   A

5. CHECK MIL (CRANKSHAFT POSITION SENSOR)

   
   

   1. Disconnect the crankshaft position sensor connector.

   2. Turn the engine switch on (IG).

   3. Check the MIL.

      Result
      Result Proceed to MIL does not illuminate A MIL illuminates B

   
   

   B

   REPLACE CRANKSHAFT POSITION SENSOR Click here

   A

6. CHECK MIL (CAMSHAFT POSITION SENSOR (FOR INTAKE CAMSHAFT))

   
   

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

   2. Turn the engine switch on (IG).

   3. Check the MIL.

      Result
      Result Proceed to MIL does not illuminate A MIL illuminates B

   
   

   B

   REPLACE CAMSHAFT POSITION SENSOR (FOR INTAKE CAMSHAFT) Click here

   A

7. CHECK MIL (CAMSHAFT POSITION SENSOR (FOR EXHAUST CAMSHAFT))

   
   

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

   2. Turn the engine switch on (IG).

   3. Check the MIL.

      Result
      Result Proceed to MIL does not illuminate A MIL illuminates B

   
   

   B

   REPLACE CAMSHAFT POSITION SENSOR (FOR EXHAUST CAMSHAFT) Click here

   A

8. CHECK MIL (MASS AIR FLOW METER SUB-ASSEMBLY)

   
   

   1. Disconnect the mass air flow meter sub-assembly connector.

   2. Turn the engine switch on (IG).

   3. Check the MIL.

      Result
      Result Proceed to MIL does not illuminate A MIL illuminates B

      Tech Tips

      Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly Click here.

   
   

   B

   REPLACE MASS AIR FLOW METER SUB-ASSEMBLY Click here

   A

9. CHECK MIL (FUEL PRESSURE SENSOR)

   
   

   1. Disconnect the fuel pressure sensor connector.

   2. Turn the engine switch on (IG).

   3. Check the MIL.

      Result
      Result Proceed to MIL does not illuminate A MIL illuminates B

   
   

   B

   REPLACE FUEL DELIVERY PIPE (FUEL PRESSURE SENSOR) Click here

   A

10. CHECK MIL (MANIFOLD ABSOLUTE PRESSURE SENSOR)

    
    

    1. Disconnect the manifold absolute pressure sensor connector.

    2. Turn the engine switch on (IG).

    3. Check the MIL.

       Result
       Result Proceed to MIL does not illuminate A MIL illuminates B

    
    

    B

    REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR Click here

    A

11. CHECK MIL (OIL PRESSURE SENDER GAUGE ASSEMBLY)

    
    

    1. Disconnect the oil pressure sender gauge assembly connector.

    2. Turn the engine switch on (IG).

    3. Check the MIL.

       Result
       Result Proceed to MIL does not illuminate A MIL illuminates B

    
    

    B

    REPLACE OIL PRESSURE SENDER GAUGE ASSEMBLY Click here

    A

12. CHECK HARNESS AND CONNECTOR

    
    

    1. Disconnect the throttle body with motor assembly connector.

    2. Disconnect the accelerator pedal sensor assembly connector.

    3. Disconnect the crankshaft position sensor connector.

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

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

    6. Disconnect the mass air flow meter sub-assembly connector.

    7. Disconnect the fuel pressure sensor connector.

    8. Disconnect the manifold absolute pressure sensor connector.

    9. Disconnect the oil pressure sender gauge assembly connector.

    10. Disconnect the ECM connectors.

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

        Standard Resistance

        Tester Connection Condition Specified Condition D87-121 (VCTA) - Body ground Always 10 kΩ or higher A75-49 (VCPA) - Body ground Always 10 kΩ or higher A75-52 (VCP2) - Body ground Always 10 kΩ or higher D87-110 (VCNE) - Body ground Always 10 kΩ or higher D87-113 (VCV1) - Body ground Always 10 kΩ or higher D87-111 (VCE1) - Body ground Always 10 kΩ or higher D87-90 (VCVG) - Body ground Always 10 kΩ or higher D87-138 (VCPM) - Body ground Always 10 kΩ or higher D87-136 (VCPR) - Body ground Always 10 kΩ or higher D87-130 (VCPE) - Body ground Always 10 kΩ or higher

    
    

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR