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Home >> Lexus >> 2012 >> IS F >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostic Codes (P1604-U0101) & 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 .

    NG → See step   5 

    OK: Go to next step 

  2. INSPECT F/PMP RELAY 
    1. Inspect the F/PMP relay. Refer to ON-VEHICLE INSPECTION - Step 10 .

    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   17 

    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 No. 2 relay block.
    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 (4) - Fuel pump resistor (A40-2) Always Below 1 Ω
      F/PMP relay (3) - Fuel pump resistor (A40-1) Always Below 1 Ω

      Standard Resistance (Check for Short)

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

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   18 

  5. PERFORM ACTIVE TEST USING TECHSTREAM (OPERATE CIRCUIT OPENING 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 /Activate the Fuel Pump Speed Control.
    4. Check the operation of the relay while operating it using the Techstream.

      OK

      Operating noise can be heard from the relay.

    NG → See step   11 

    OK: Go to next step 

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

    NG → See step   19 

    OK: Go to next step 

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

        Standard Resistance (Check for Open)

        Tester Connection Condition Specified Condition
        Fuel pump (Q14-4) - F/PMP relay (4) Always Below 1 Ω

        Standard Resistance (Check for Short)

        Tester Connection Condition Specified Condition
        Fuel pump (Q14-4) or F/PMP (4) - Body ground Always 10 kΩ or higher
      4. Reinstall the F/PMP relay.
    2. Check the harness and the connectors between the fuel pump and body ground.
      1. Measure the resistance according to the value(s) in the table below.

        Standard Resistance (Check for Open)

        Tester Connection Condition Specified Condition
        Fuel pump (Q14-5) - Body ground Always 10 kΩ or higher
      2. Reconnect the fuel pump connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  8. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - F/PMP RELAY) 
    1. Remove the integration relay from the engine room No. 2 relay block.
    2. Remove the F/PMP relay from the engine room No. 2 relay block.
    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 (1) Always Below 1 Ω
      2B-8 - F/PMP relay (3) Always Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      2B-8 or F/PMP relay (1) - Body ground Always 10 kΩ or higher
      2B-8 or F/PMP relay (3) - Body ground Always 10 kΩ or higher
    4. Reinstall the relays.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  9. 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
      Fuel pump (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 

  10. CHECK FUEL LINE 
    1. Check the fuel lines for leaks or blockage.

      OK

      No leaks or blockage

    NG → REPAIR OR REPLACE FUEL LINE 

    OK → REPAIR OR REPLACE FUEL SYSTEM (PRESSURE REGULATOR AND FUEL FILTER) 

  11. INSPECT FUSE (F/PMP FUSE) 
    1. Remove the F/PMP fuse from the engine room No. 2 relay block.
      Fig 1: Identifying F/PMP Fuse
      GTY105480Courtesy 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
      F/PMP fuse Always Below 1 Ω
    3. Reinstall the F/PMP fuse.

    NG → CHECK FOR SHORT IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE (F/PMP FUSE) 

    OK: Go to next step 

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

    NG → See step   15 

    OK: Go to next step 

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

    NG → See step   15 

    OK: Go to next step 

  14. INSPECT ECM (FC VOLTAGE) 
    1. Turn the engine switch on (IG).
      Fig 2: Identifying ECM Connector E6 And A5
      GTY142809Courtesy 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
      A5-5 (FC) - E6-1 (E1) Engine Switch on (IG) 11 to 14 V

    NG → CHECK AND REPAIR HARNESS AND CONNECTOR (ECM - C/OPN RELAY) 

    OK → See step   16 

  15. REPLACE INTEGRATION RELAY. Refer to  REMOVAL 
  16. REPLACE ECM. Refer to  REMOVAL 
  17. REPLACE FUEL PUMP RESISTOR. Refer to  REMOVAL 
  18. PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE 
  19. REPLACE FUEL PUMP. Refer to  REMOVAL 
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