ECD 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 has a short circuit, the CPU 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

CAUTION / NOTICE / HINT

PROCEDURE

1. CHECK CONNECTION BETWEEN GTS AND ECM

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the ignition switch to ON and GTS on.

   3. Check the communication between the GTS and ECM.

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

   
   

   B

   GO TO MIL CIRCUIT Click here

   A

2. CHECK TERMINAL VOLTAGE (POWER SOURCE OF ECM)

   
   

   1. Turn the ignition switch to ON.

   2. 

      *a	Component with harness connected (ECM)

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

      Standard Voltage
      Tester Connection Condition Specified Condition G84-1 (+B) - C56-7 (E1) IG ON 11 to 14 V

      Result
      Proceed to OK NG

      Tech Tips

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

   
   

   NG

   GO TO ECM POWER SOURCE CIRCUIT Click here

   OK

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

   
   

   1. Disconnect the throttle 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

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

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

   5. Reconnect the throttle position sensor connector.

   
   

   B

   REPLACE DIESEL THROTTLE BODY ASSEMBLY Click here REPLACE DIESEL THROTTLE BODY ASSEMBLY Click here

   A

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

   
   

   1. Disconnect the manifold absolute 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

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

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

   5. Reconnect the manifold absolute pressure sensor connector.

   
   

   B

   REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR Click here

   A

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

   
   

   1. Disconnect the accelerator pedal position sensor connector.

   2. Turn the ignition switch to ON.

   3. Turn the GTS on.

   4. Check the communication between the GTS and ECM.Check the MIL.

      Tech Tips

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

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

   5. Reconnect the accelerator position sensor connector.

   
   

   B

   REPLACE ACCELERATOR PEDAL ROD ASSEMBLY Click here

   A

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

   
   

   1. Disconnect the 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

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

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

   5. Reconnect the fuel pressure sensor connector.

   
   

   B

   REPLACE COMMON RAIL ASSEMBLY Click here

   A

7. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND)

   
   

   1. Disconnect the throttle position sensor connector.

   2. Disconnect the manifold absolute pressure sensor connector.

   3. Disconnect the fuel pressure sensor connector.

   4. Disconnect the accelerator pedal position sensor connector.

   5. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition C55-18 (VC) - Body ground Always 10 kΩ or higher C56-2 (VCS) - Body ground Always 10 kΩ or higher G84-26 (VCPA) - Body ground Always 10 kΩ or higher G84-27 (VCP2) - Body ground Always 10 kΩ or higher

   7. Reconnect the throttle position sensor connector.

   8. Reconnect the manifold absolute pressure sensor connector.

   9. Reconnect the fuel pressure sensor connector.

   10. Reconnect the accelerator pedal position sensor connector.

   11. Reconnect the ECM connector.

       Result
       Proceed to OK NG

   
   

   OK

   REPLACE ECM Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR