Sfi System Fuel Pump Control Circuit

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (ACTIVE THE FUEL PUMP SPEED CONTROL)

INSPECT MAIN BODY ECU (C/OPN RELAY INPUT VOLTAGE)

CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 1 RELAY BLOCK - MAIN BODY ECU, MAIN BODY ECU - INTEGRATION RELAY)

INSPECT MAIN BODY ECU (C/OPN RELAY)

CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - ECM)

CHECK HARNESS AND CONNECTOR (C/OPN RELAY - FUEL PUMP - BODY GROUND)

INSPECT FUEL PUMP

READ VALUE USING INTELLIGENT TESTER (STARTER SIGNAL)

READ VALUE USING INTELLIGENT TESTER (ENGINE SPEED)

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch on (IG) and turn the tester ON.
   

3. Select the following menu items: Powertrain / Engine and ECT / Active Test / Control the Fuel Pump / Speed.
   

4. Check whether the fuel pump operating sound occurs when performing the Active Test on the tester.
   

   OK:

   Fuel pump operating sound occurs.
   

1. Measure the voltage between the terminal of the main body ECU (instrument panel junction block) and the body ground when the ignition switch is turned on (IG) and off.
   

   Standard voltage:

   Tester Connection	Ignition Switch Condition	Specified Condition
   IB-11 - Body ground	off	Below 1 V
   IF-4 - Body ground
   IB-11 - Body ground	on (IG)	9 to 14 V
   IF-4 - Body ground

1. Remove the IG2 relay from the engine room No. 1 relay block.
   

2. Remove the integration relay from the engine room No. 1 relay block (R/B).
   

3. Disconnect the IB and IF connectors from the main body ECU (instrument panel junction block).
   

4. Measure the resistance.
   

   Standard resistance (Check for open):

   Tester Connection	Specified Condition
   Relay Block IG2 relay block terminal (5) - IF-4	Below 1 Ω
   Relay Block (1A-4) - IB-11	Below 1 Ω

   Standard resistance (Check for short):

   Tester Connection	Specified Condition
   IF-4 - Body ground	10 kΩor higher
   IB-11 - Body ground	10 kΩor higher

5. Reinstall the IG2 relay.
   

6. Reinstall the integration relay.
   

7. Reconnect the main body ECU (instrument panel junction block) connectors.
   

1. Remove the main body ECU (instrument panel junction block).
   

2. Measure the C/OPN relay resistance.
   

   Standard resistance:

   Tester Connection	Specified Condition
   IB-11 - IA-8	10 kΩ or higher
   	Below 1 Ω (when battery voltage is applied to terminals IB-9 and IE-5)

   HINT:

   Relay coil circuit between IB-9 and IE-5 is not through IGN fuse.

3. Reinstall the main body ECU (instrument panel junction block).
   

1. Disconnect the A12 ECM connector.
   

2. Disconnect the IE connector from main body ECU (instrument panel junction block).
   

3. Measure the resistance.
   

   Standard resistance (Check for open):

   Tester Connection	Specified Condition
   IE-5 - FC (A12-7)	Below 1Ω

   Standard resistance (Check for short):

   Tester Connection	Specified Condition
   IE-5 or FC (A12-7) - Body ground	10 kΩ or higher

4. Reconnect the main body ECU (instrument panel junction block) and the ECM connectors.
   

1. Check the harness and the connectors between the main body ECU (instrument panel junction block) and the fuel pump.
   

   1. Disconnect the IA connector from main body ECU (instrument panel junction block).
      

   2. Disconnect the T1 fuel pump connector.
      

   3. Measure the resistance.
      

      Standard resistance (Check for open):

      Tester Connection	Specified Condition
      IA-8 - Fuel pump (T1-4)	Below 1Ω

      Standard resistance (Check for short):

      Tester Connection	Specified Condition
      IA-8 or Fuel pump (T1-4) - Body ground	10 kΩ or higher

2. Check the harness and the connectors between the fuel pump and the body ground.
   

   1. Disconnect the T1 fuel pump connector.
      

   2. Measure the resistance.
      

      Standard resistance (Check for open):

      Tester Connection	Specified Condition
      Fuel pump (T1-5) - Body ground	Below 1 Ω

3. Reconnect the Main body ECU (instrument panel junction block) connector.
   

4. Reconnect the fuel pump connector.
   

1. Inspect fuel pump resistance.
   

   1. Measure the resistance between the terminals.
      

      Standard resistance:

      0.2 to 3.0 Ω at 20°C(68°F)
      

2. Inspect fuel pump operation.
   

   1. Apply the battery voltage to both the terminals.
      

   2. Check that the pump operates.
      

      NOTICE:

      1. These tests must be done quickly (within 10 seconds) to prevent the coil from burning out.
         
      2. Keep the fuel pump as far away from the battery as possible.
         
      3. Always turn the voltage on and off on the battery side, not the fuel pump side.
         

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch on (IG) and turn the tester ON.
   

3. Select the following menu items: Powertrain / Engine and ECT / Data List / Starter Signal.
   

4. Check the result when the ignition switch is turned on (IG) and START.
   

   OK:

   Ignition Switch Position	Starter Signal
   ON	OFF
   START	ON

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch on (IG) and turn the tester ON.
   

3. Select the following menu items: Powertrain / Engine and ECT / Data List / Engine Speed.
   

4. Read the values displayed on the tester while cranking.
   

   OK:

   Values are displayed continuously.