SFI SYSTEM VC Output Circuit

DESCRIPTION

The ECM constantly generates a 5 V power source voltage from the auxiliary battery voltage 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 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

• For the circuit diagram of the ECM power source refer to the ECM power source circuit.

  Click here

• VC Output Circuit

  

CAUTION / NOTICE / HINT

PROCEDURE

1. CHECK CONNECTION BETWEEN GTS AND ECM

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the power 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" 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 and No. 1 Junction Block Assembly
   *2	EFI NO. 2 Fuse

   
   

   1. Turn the power 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 power switch on (IG) 11 to 14 V

      Tech Tips

      
      

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

      • 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 Click here

   OK

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

   
   

   1. Disconnect the throttle body with motor assembly connector.

   2. Turn the power 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" 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 (CAMSHAFT POSITION SENSOR (FOR INTAKE CAMSHAFT))

   
   

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

   2. Turn the power 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" 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

5. 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 power 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" 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

6. CHECK CONNECTION BETWEEN GTS AND ECM (MANIFOLD ABSOLUTE PRESSURE SENSOR)

   
   

   1. Disconnect the manifold absolute pressure sensor connector.

   2. Turn the power 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" item of the Data List.

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

   
   

   B

   REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR Click here

   A

7. CHECK CONNECTION BETWEEN GTS AND ECM (FUEL PRESSURE SENSOR)

   
   

   1. Disconnect the fuel pressure sensor connector.

   2. Turn the power 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" item of the Data List.

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

   
   

   B

   REPLACE FUEL DELIVERY PIPE SUB-ASSEMBLY (FUEL PRESSURE SENSOR) Click here

   A

8. CHECK HARNESS AND CONNECTOR

   
   

   1. Disconnect the throttle body with motor assembly connector.

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

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

   4. Disconnect the manifold absolute pressure sensor connector.

   5. Disconnect the fuel pressure sensor connector.

   6. Disconnect the ECM connectors.

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

      Standard Resistance

      Tester Connection Condition Specified Condition F6-102 (VCPR) - Body ground Always 10 kΩ or higher F6-111 (VCE1) - Body ground Always 10 kΩ or higher F6-113 (VCV1) - Body ground Always 10 kΩ or higher F6-125 (VCTA) - Body ground Always 10 kΩ or higher F6-78 (VCPM) - Body ground Always 10 kΩ or higher A72-2 (+B) - 1 (EFI NO. 2 fuse) Always Below 1 Ω A72-3 (+B2) - 1 (EFI NO. 2 fuse) Always Below 1 Ω A72-2 (+B) - Body ground Always 10 kΩ or higher A72-3 (+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