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Home >> Lexus >> 2011 >> IS 250C Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (4GR-FSE) (Diagnostic Codes & Circuit Tests) >> SFI System >> Circuit Tests >> Fuel Pump Control Circuit >> Procedure
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Fuel Pump Control Circuit: Procedure

  1. CHECK FUEL PUMP OPERATION 
    1. Check the fuel pump operation. Refer to ON-VEHICLE INSPECTION - Step 1 .

    NG → See step   5 

    OK: Go to next step 

  2. INSPECT F/PMP RELAY 
    1. Remove the F/PMP relay from the engine room relay block No. 2.
      Fig 1: Identifying Relay Test Terminals
      GTY104187Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      3 - 4 No battery voltage applied across terminals 1 and 2 Below 1 Ω
      3 - 4 Battery voltage applied across terminals 1 and 2 10 kΩ or higher
    3. Reinstall the F/PMP relay.

    NG → REPLACE F/PMP RELAY 

    OK: Go to next step 

  3. INSPECT FUEL PUMP RESISTOR 
    1. Inspect the fuel pump resistor. Refer to INSPECTION .

    NG → See step   15 

    OK: Go to next step 

  4. CHECK HARNESS AND CONNECTOR (F/PMP RELAY - FUEL PUMP RESISTOR) 
    1. Remove the F/PMP relay from the engine room relay block No. 2.
    2. Disconnect the fuel pump resistor connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      F/PMP relay terminal 4 - A40-2 Always Below 1 Ω
      F/PMP relay terminal 3 - A40-1 Always Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      Fuel pump relay terminal 4 or A40-2 - Body ground Always 10 kΩ or higher
      Fuel pump relay terminal 3 or A40-1 - Body ground Always 10 kΩ or higher
    4. Reinstall the F/PMP relay.
    5. Reconnect the fuel pump resistor connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   16 

  5. PERFORM ACTIVE TEST USING TECHSTREAM (OPERATE C/OPN RELAY) 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG) and turn the Techstream on.
    3. Enter the following menus: Powertrain / Engine / Active Test / Control the Fuel Pump / Speed.
    4. Check the operation of the relay while operating it using the Techstream.

      OK

      Operating noise can be heard from the C/OPN relay.

    NG → See step   10 

    OK: Go to next step 

  6. INSPECT FUEL PUMP 
    1. Inspect the fuel pump. Refer to INSPECTION .

    NG → See step   17 

    OK: Go to next step 

  7. CHECK HARNESS AND CONNECTOR (FUEL PUMP - F/PMP RELAY) 
    1. Disconnect the fuel pump connector.
    2. Remove the F/PMP relay from the engine room relay block No. 2.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      F/PMP relay terminal 4 - Q14-4 Always Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      F/PMP relay terminal 4 or Q14-4 - Body ground Always 10 kΩ or higher
    4. Reinstall the F/PMP relay.
    5. Reconnect the fuel pump connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  8. CHECK HARNESS AND CONNECTOR (FUEL PUMP - BODY GROUND) 
    1. Disconnect the fuel pump connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      Q14-5 - Body ground Always Below 1 Ω
    3. Reconnect the fuel pump connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  9. CHECK HARNESS AND CONNECTOR (C/OPN RELAY - F/PMP RELAY) 
    1. Remove the integration relay from the engine room relay block No. 2.
    2. Remove the F/PMP relay from the engine room relay block No. 2.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      2B-8 - F/PMP relay terminal 1 Always Below 1 Ω
      2B-8 - F/PMP relay terminal 3 Always Below 1 Ω
    4. Disconnect the fuel pump resistor connector.
    5. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      2B-8 or F/PMP relay terminal 1 - Body ground Always 10 kΩ or higher
      2B-8 or F/PMP relay terminal 3 - Body ground Always 10 kΩ or higher
    6. Reinstall the relays.
    7. Reconnect the fuel pump resistor connector.

    NG → REPLACE ENGINE ROOM RELAY BLOCK NO. 2 

    OK → REPAIR OR REPLACE FUEL SYSTEM 

  10. INSPECT INTEGRATION RELAY (EFI NO. 2 RELAY) 
    1. Inspect the EFI No. 2 relay. Refer to INSPECTION .

    NG → See step   13 

    OK: Go to next step 

  11. INSPECT INTEGRATION RELAY (C/OPN RELAY) 
    1. Inspect the C/OPN relay. Refer to INSPECTION .

    NG → See step   13 

    OK: Go to next step 

  12. INSPECT ECM (FC VOLTAGE) 
    1. Turn the engine switch on (IG).
      Fig 2: E4 & A5 Connectors
      GTY354067Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      A5-14 (FC) - E4-7 (E1) Engine switch on (IG) 11 to 14 V
      TEXT IN ILLUSTRATION

      *a Component with harness connected
      (ECM)

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - C/OPN RELAY) 

    OK → See step   14 

  13. REPLACE INTEGRATION RELAY. Refer to  REMOVAL 
  14. REPLACE ECM. Refer to  REMOVAL 
  15. REPLACE FUEL PUMP RESISTOR. Refer to  REMOVAL 
  16. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE 
  17. REPLACE FUEL PUMP. Refer to  REMOVAL 
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