SFI SYSTEM(w/ EGR System) Fuel Pump Control Circuit

DTC Code DTC Name
Fuel Pump Control Circuit

DESCRIPTION

The fuel pump circuit consists of the ECM, fuel pump and fuel pump ECU (which operates the fuel pump). Based on the engine output, the ECM determines the fuel pump speed. The speed is then converted to a duty signal and sent to the fuel pump ECU. Based on the signal sent from the ECM, the fuel pump ECU adjusts the fuel pump operation speed among 3 settings.

WIRING DIAGRAM

A231458E08

CAUTION / NOTICE / HINT

Note:

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

This troubleshooting procedure is based on the premise that the engine can be started. If the engine cannot be started, proceed to Problem Symptoms Table (Click here).

PROCEDURE

  1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER

    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the tester on.

    4. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Fuel Pump / Speed.

      Powertrain > Engine and ECT > Active Test

      Tester Display

      Control the Fuel Pump / Speed

    5. Check whether operating sounds can be heard while operating the fuel pump using the intelligent tester.

      OK

      Operating sounds can be heard from fuel pump.

      Result

      Result

      OK

      NG
    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    Click here

    NG

  2. INSPECT CIRCUIT OPENING RELAY (C/OPN)

    1. Inspect the circuit opening relay (C/OPN).

      Click here

      Result

      Result

      OK

      NG
    NG

    REPLACE CIRCUIT OPENING RELAY (C/OPN)

    OK

  3. INSPECT CIRCUIT OPENING RELAY (C/OPN) (POWER SOURCE VOLTAGE)

    1. Remove the circuit opening relay (C/OPN) from the engine room relay block.

    2. Turn the engine switch on (IG).

    3. A227634C02

      *1

      Engine Room Relay Block

      *2

      Circuit Opening Relay (C/OPN)

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      C/OPN relay (2) - Body ground

      Engine switch on (IG)

      11 to 14 V

      C/OPN relay (5) - Body ground

      Engine switch on (IG)

      11 to 14 V

      Result

      Result

      OK

      NG
    NG

    CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY (C/OPN) - FUEL PUMP RELAY (F/PMP) AND NO. 1 INTEGRATION RELAY)Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY (C/OPN) - ECM AND FUEL PUMP ECU)

    1. Remove the circuit opening relay (C/OPN) from the engine room relay block.

    2. Disconnect the ECM connector.

    3. Disconnect the fuel pump ECU connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      C/OPN relay (1) - G45-8 (FC)

      Always

      Below 1 Ω

      C/OPN relay (3) - S7-4 (+B)

      Always

      Below 1 Ω

      C/OPN relay (1) or G45-8 (FC) - Body ground

      Always

      10 kΩ or higher

      C/OPN relay (3) or S7-4 (+B) - Body ground

      Always

      10 kΩ or higher

      Result

      Result

      OK

      NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (FUEL PUMP - FUEL PUMP ECU)

    1. Disconnect the fuel pump connector.

    2. Disconnect the fuel pump ECU connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      S4-4 (B2) - S8-1 (FP)

      Always

      Below 1 Ω

      S4-5 (E2) - S8-2 (FP-)

      Always

      Below 1 Ω

      S4-4 (B2) or S8-1 (FP) - Body ground

      Always

      10 kΩ or higher

      S4-5 (E2) or S8-2 (FP-) - Body ground

      Always

      10 kΩ or higher

      Result

      Result

      OK

      NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT FUEL PUMP

    1. Inspect the fuel pump.

      Click here

      Result

      Result

      OK

      NG
    NG

    REPLACE FUEL PUMP

    Click here

    OK

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

    1. Disconnect the fuel pump ECU connector.

    2. Disconnect the ECU connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      S7-1 (FPC) - G44-3 (FPC)

      Always

      Below 1 Ω

      S7-2 (DI) - G45-26 (DI)

      Always

      Below 1 Ω

      S7-3 (E) - Body ground

      Always

      Below 1 Ω

      S7-1 (FPC) or G44-3 (FPC) - Body ground

      Always

      10 kΩ or higher

      S7-2 (DI) or G45-26 (DI) - Body ground

      Always

      10 kΩ or higher

      Result

      Result

      OK

      NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. REPLACE FUEL PUMP ECU

    1. Replace the fuel pump ECU.

      Click here

      Result

      Result

      NEXT
    NEXT

  9. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

    1. Check the fuel pump operation.

      OK

      Malfunction has been repaired successfully.

      Result

      Result

      OK

      NG
    OK

    END

    NG

    REPLACE ECM

    Click here

  10. CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY (C/OPN) - FUEL PUMP RELAY (F/PMP) AND NO. 1 INTEGRATION RELAY)

    1. Remove the circuit opening relay (C/OPN) from the engine room relay block.

    2. Remove the fuel pump relay (F/PMP) from the engine room relay block.

    3. Remove the No. 1 integration relay from the engine room relay block.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      C/OPN relay (2) - 1A-5

      Always

      Below 1 Ω

      C/OPN relay (5) - F/PMP relay (3)

      Always

      Below 1 Ω

      C/OPN relay (2) or 1A-5 - Body ground

      Always

      10 kΩ or higher

      C/OPN relay (5) or F/PMP relay (3) - Body ground

      Always

      10 kΩ or higher

      Result

      Result

      OK

      NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. INSPECT FUEL PUMP RELAY (F/PMP)

    1. Inspect the fuel pump relay (F/PMP)

      Click here

      Result

      Result

      OK

      NG
    NG

    REPLACE FUEL PUMP RELAY (F/PMP)

    OK

  12. CHECK HARNESS AND CONNECTOR (FUEL PUMP RELAY (F/PMP) - NO. 1 INTEGRATION RELAY, BATTERY AND BODY GROUND)

    1. Remove the fuel pump relay (F/PMP) from the engine room relay block.

    2. Remove the No. 1 integration relay from the engine room relay block.

    3. Disconnect the No. 1 integration relay connector.

    4. Disconnect the cable from the battery positive (+) terminal.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      F/PMP relay (1) - 1B-4

      Always

      Below 1 Ω

      F/PMP relay (5) - Positive (+) battery cable

      Always

      Below 1 Ω

      F/PMP relay (2) - Body ground

      Always

      Below 1 Ω

      F/PMP relay (1) or 1B-4 - Body ground

      Always

      10 kΩ or higher

      F/PMP relay (5) or Positive (+) battery cable - Body ground

      Always

      10 kΩ or higher

      Result

      Result

      OK

      NG
    OK

    GO TO ECM POWER SOURCE CIRCUIT

    Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR