SFI SYSTEM 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 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

• ECM Power Source Circuit

  Click here

• VC Output Circuit

  

  

  

  *a	VCPE
  *b	Oil Pressure Sender Gauge Assembly
  *c	EPEO
  *d	PEO

CAUTION / NOTICE / HINT

PROCEDURE

1. CHECK COMMUNICATION BETWEEN GTS AND ECM

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the ignition switch to ON.

   3. Turn the GTS on.

   4. Check the communication between the GTS and ECM.

      Tech Tips

      The Data List item "Engine" can be checked.

      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 TERMINAL VOLTAGE (POWER SOURCE OF ECM)

   
   
   1. 

      *1	No. 1 Engine Room Relay Block
      *2	EFI NO. 3 Fuse

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

      Standard Voltage
      Tester Connection Condition Specified Condition 1 (EFI NO. 3 fuse) - Body ground Always 11 to 14 V

      Tech Tips

      
      

      • Check that a EFI NO. 3 fuse is installed in the 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

   CHECK ECU POWER SOURCE CIRCUIT Click here

   OK

3. CHECK COMMUNICATION BETWEEN THE GTS AND ECM (ACCELERATOR PEDAL SENSOR ASSEMBLY)

   
   

   1. Disconnect the A46 accelerator pedal sensor assembly connector.

   2. Turn the ignition switch to ON.

   3. Turn the GTS on.

   4. Check the communication between the GTS and ECM.

      Tech Tips

      The Data List item "Engine" can be checked.

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

   
   

   B

   REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY Click here

   A

4. CHECK COMMUNICATION BETWEEN THE GTS AND ECM (CAMSHAFT POSITION SENSOR (FOR INTAKE CAMSHAFT))

   
   

   1. Disconnect the C19 camshaft position sensor (for intake camshaft) connector.

   2. Turn the ignition switch to ON.

   3. Turn the GTS on.

   4. Check the communication between the GTS and ECM.

      Tech Tips

      The Data List item "Engine" can be checked.

      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 COMMUNICATION BETWEEN THE GTS AND ECM (CAMSHAFT POSITION SENSOR (FOR EXHAUST CAMSHAFT))

   
   

   1. Disconnect the W1 camshaft position sensor (for exhaust camshaft) connector.

   2. Turn the ignition switch to ON.

   3. Turn the GTS on.

   4. Check the communication between the GTS and ECM.

      Tech Tips

      The Data List item "Engine" can be checked.

      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 COMMUNICATION BETWEEN THE GTS AND ECM (CRANKSHAFT POSITION SENSOR)

   
   

   1. Disconnect the C29 crankshaft position sensor connector.

   2. Turn the ignition switch to ON.

   3. Turn the GTS on.

   4. Check the communication between the GTS and ECM.

      Tech Tips

      The Data List item "Engine" can be checked.

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

   
   

   B

   REPLACE CRANKSHAFT POSITION SENSOR Click here

   A

7. CHECK COMMUNICATION BETWEEN THE GTS AND ECM (THROTTLE BODY WITH MOTOR ASSEMBLY)

   
   

   1. Disconnect the C4 throttle body with motor assembly connector.

   2. Turn the ignition switch to ON.

   3. Turn the GTS on.

   4. Check the communication between the GTS and ECM.

      Tech Tips

      The Data List item "Engine" can be checked.

      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

8. CHECK COMMUNICATION BETWEEN THE GTS AND ECM (NO. 1 TURBO PRESSURE SENSOR)

   
   

   1. Disconnect the C3 No. 1 turbo pressure sensor connector.

   2. Turn the ignition switch to ON.

   3. Turn the GTS on.

   4. Check the communication between the GTS and ECM.

      Tech Tips

      The Data List item "Engine" can be checked.

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

   
   

   B

   REPLACE NO. 1 TURBO PRESSURE SENSOR Click here

   A

9. CHECK COMMUNICATION BETWEEN THE GTS AND ECM (NO. 2 TURBO PRESSURE SENSOR)

   
   

   1. Disconnect the C39 No. 2 turbo pressure sensor connector.

   2. Turn the ignition switch to ON.

   3. Turn the GTS on.

   4. Check the communication between the GTS and ECM.

      Tech Tips

      The Data List item "Engine" can be checked.

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

   
   

   B

   REPLACE NO. 2 TURBO PRESSURE SENSOR Click here

   A

10. CHECK COMMUNICATION BETWEEN THE GTS AND ECM (FUEL DELIVERY PIPE (FUEL PRESSURE SENSOR))

    
    

    1. Disconnect the C54 fuel delivery pipe (fuel pressure sensor) connector.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Check the communication between the GTS and ECM.

       Tech Tips

       The Data List item "Engine" can be checked.

       Result
       Result Proceed to Communication is not possible (for CVT) A Communication is not possible (for Manual Transaxle) B Communication is possible C

    
    

    B

    CHECK COMMUNICATION BETWEEN THE GTS AND ECM (CLUTCH PEDAL STROKE SENSOR ASSEMBLY) Click here

    C

    REPLACE FUEL DELIVERY PIPE (FUEL PRESSURE SENSOR) Click here

    A

11. CHECK COMMUNICATION BETWEEN THE GTS AND ECM (OIL PRESSURE SENSOR)

    
    

    1. Disconnect the C44 oil pressure sensor connector.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Check the communication between the GTS and ECM.

       Tech Tips

       The Data List item "Engine" can be checked.

       Result
       Result Proceed to Communication is not possible A Communication is possible (for 2WD) B Communication is possible (for AWD) C

    
    

    B

    REPLACE OIL PRESSURE SENSOR Click here

    C

    REPLACE OIL PRESSURE SENSOR Click here

    A

12. CHECK COMMUNICATION BETWEEN THE GTS AND ECM (OIL PRESSURE SENDER GAUGE ASSEMBLY)

    
    

    1. Disconnect the C58 oil pressure sender gauge assembly connector.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Check the communication between the GTS and ECM.

       Tech Tips

       The Data List item "Engine" can be checked.

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

    
    

    B

    REPLACE OIL PRESSURE SENDER GAUGE ASSEMBLY Click here

    A

13. CHECK HARNESS AND CONNECTOR

    
    

    1. Disconnect the A46 accelerator pedal sensor assembly connector.

    2. Disconnect the C19 camshaft position sensor (for intake camshaft) connector.

    3. Disconnect the W1 camshaft position sensor (for exhaust camshaft) connector.

    4. Disconnect the C29 crankshaft position sensor connector.

    5. Disconnect the C4 throttle body with motor assembly connector.

    6. Disconnect the C3 No. 1 turbo pressure sensor connector.

    7. Disconnect the C39 No. 2 turbo pressure sensor connector.

    8. Disconnect the C54 fuel delivery pipe (fuel pressure sensor) connector.

    9. Disconnect the C44 oil pressure sensor connector. *1

    10. Disconnect the A47 clutch pedal stroke sensor assembly connector. *2

    11. Disconnect the C58 oil pressure sensor gauge assembly connector.

    12. Disconnect the A38 and C62 ECM connectors.

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

        Standard Resistance

        Tester Connection Condition Specified Condition A38-49 (VCPA) - Body ground and other terminals Always 10 kΩ or higher C62-113 (VCV1) - Body ground and other terminals Always 10 kΩ or higher C62-111 (VCE1) - Body ground and other terminals Always 10 kΩ or higher C62-110 (VCNE) - Body ground and other terminals Always 10 kΩ or higher C62-121 (VCTA) - Body ground and other terminals Always 10 kΩ or higher C62-140 (VPTA) - Body ground and other terminals Always 10 kΩ or higher C62-138 (VCPM) - Body ground and other terminals Always 10 kΩ or higher C62-136 (VCPR) - Body ground and other terminals Always 10 kΩ or higher C62-118 (VCPT)*1 - Body ground and other terminals Always 10 kΩ or higher C62-89 (VCCL)*2 - Body ground and other terminals Always 10 kΩ or higher C62-130 (VCPE) - Body ground and other terminals Always 10 kΩ or higher 1 (EFI NO. 3 fuse holder) - A38-2 (+B) Always Below 1 Ω 1 (EFI NO. 3 fuse holder) - A38-3 (+B2) Always Below 1 Ω A38-2 (+B) - Body ground and other terminals Always 10 kΩ or higher A38-3 (+B2) - Body ground and other terminals Always 10 kΩ or higher

        
        

        • *1: for CVT

        • *2: for Manual Transaxle

        Result
        Proceed to OK NG

    
    

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

14. CHECK COMMUNICATION BETWEEN THE GTS AND ECM (CLUTCH PEDAL STROKE SENSOR ASSEMBLY)

    
    

    1. Disconnect the A47 clutch pedal stroke sensor assembly connector.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Check the communication between the GTS and ECM.

       Tech Tips

       The Data List item "Engine" can be checked.

       Result
       Result Proceed to Communication is not possible A Communication is possible (for LHD) B Communication is possible (for RHD) C

    
    

    A

    GO TO STEP 12 Click here

    B

    REPLACE CLUTCH PEDAL STROKE SENSOR (CLUTCH PEDAL STROKE SENSOR ASSEMBLY) Click here

    C

    REPLACE CLUTCH PEDAL STROKE SENSOR (CLUTCH PEDAL STROKE SENSOR ASSEMBLY) Click here