SFI SYSTEM VC Output Circuit

DESCRIPTION

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

When the VC circuit is short-circuited, the microprocessor in the ECM and the sensors that are supplied with power through the VC circuit are inactivated because 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

*a	Throttle Body Assembly
*b	Accelerator Pedal Sensor Assembly
*c	Camshaft Position Sensor (for Intake Camshaft)
*d	Camshaft Position Sensor (for Exhaust Camshaft)

*a	Crankshaft Position Sensor
*b	Manifold Absolute Pressure Sensor
*c	Oil Pressure Sensor

PROCEDURE

1. CHECK MIL CONDITION

   
   

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

      OK
      MIL lights up.

      Result
      Proceed to OK NG

   
   

   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 for 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 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 assembly.

      Click here

   
   

   B

   REPLACE THROTTLE BODY ASSEMBLY Click here

   A

4. CHECK MIL (ACCELERATOR PEDAL SENSOR ASSEMBLY)

   
   

   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 (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

6. 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

7. 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

8. CHECK MIL (OIL PRESSURE SENSOR)

   
   

   1. Disconnect the oil 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 OIL PRESSURE SENSOR for 2WD Click here for AWD Click here

   A

9. 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

10. CHECK HARNESS AND CONNECTOR

    
    

    1. Disconnect the throttle body assembly connector.

    2. Disconnect the accelerator pedal sensor assembly connector.

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

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

    5. Disconnect the manifold absolute pressure sensor connector.

    6. Disconnect the oil pressure sensor connector.

    7. Disconnect the crankshaft position 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 C65-134 (VCTA) - Body ground and other terminals Always 10 kΩ or higher A35-49 (VCPA) - Body ground and other terminals Always 10 kΩ or higher A35-52 (VCP2) - Body ground and other terminals Always 10 kΩ or higher C65-116 (VCV1) - Body ground and other terminals Always 10 kΩ or higher C65-111 (VCE1) - Body ground and other terminals Always 10 kΩ or higher C65-77 (VCPM) - Body ground and other terminals Always 10 kΩ or higher C65-110 (VCPT) - Body ground and other terminals Always 10 kΩ or higher C65-81 (VCNE) - Body ground and other terminals Always 10 kΩ or higher

       Result
       Proceed to OK NG

    
    

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR