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Home >> Honda >> 2021 >> Pilot Special Edition, AWD >> Repair and Diagnosis >> Engine Performance >> Fuel Delivery >> Fuel And Emissions - Testing & Troubleshooting >> Troubleshooting >> FUEL PUMP CIRCUIT (6-Speed A/T), ('16-'18 9-Speed A/T)

FUEL PUMP CIRCUIT (6-Speed A/T), ('16-'18 9-Speed A/T)

If you suspect a problem with the fuel pump, check that the fuel pump actually runs; when it is on, you will hear some noise if you listen to the fuel fill port with the fuel fill cap removed. The fuel pump should run for 2 seconds when the vehicle is turned to ON mode. If the fuel pump does not make noise, check as follows:

  1. Under-dash fuse/relay box internal circuit check

    -1. Turn the vehicle to the OFF (LOCK) mode.

    - 2. Remove PGM-FI main relay 2 (A) from the auxiliary under-hood fuse/relay box.

    GHH309405Courtesy of HONDA, U.S.A., INC.

    - 3. Turn the vehicle to the ON mode.

    - 4. Measure the voltage between test points 1 and 2.

    Test condition Vehicle ON mode
    PGM-FI main relay 2: disconnected
    Test point 1 PGM-FI main relay 2 4P socket No. 3
    Test point 2 Body ground
    GHH309406Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    Go to step 3.

    NO 

    Go to step 2.

  2. Open wire check (IGP line)

    -1. Turn the vehicle to the OFF (LOCK) mode.

    - 2. Disconnect the following connectors.

    Relay circuit board connector B (16P)

    - 3. Connect terminals A and B with a jumper wire.

    Terminal A Relay circuit board connector B (16P) No. 9
    Terminal B Body ground

    - 4. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    PGM-FI main relay 2: disconnected
    Relay circuit board connector B (16P): jumped to body ground
    Test point 1 PGM-FI main relay 2 4P socket No. 3
    Test point 2 Body ground
    GHH309407Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Test the Relay Circuit Board .

    If needed, replace the Relay Circuit Board - Removal and Installation .

    NO 

    Repair an open in the IGP wire between the relay circuit board and the auxiliary under-hood fuse/relay box.

  3. Open wire check (IG1 FUEL PUMP line)

    -1. Measure the voltage between test points 1 and 2.

    Test condition Vehicle ON mode
    PGM-FI main relay 2: disconnected
    Test point 1 PGM-FI main relay 2 4P socket No. 2
    Test point 2 Body ground
    GHH309408Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    Go to step 4.

    NO 

  4. Open wire check (IMOFLR line)

    -1. Turn the vehicle to the OFF (LOCK) mode.

    - 2. Jump the SCS line with the HDS, and wait more than 1 minute.

    - 3. Disconnect the following connector.

    PCM connector A (51P)

    - 4. Connect terminals A and B with a jumper wire.

    Terminal A PGM-FI main relay 2 4P socket No. 4
    Terminal B Body ground
    GHH309409Courtesy of HONDA, U.S.A., INC.

    - 5. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    PGM-FI main relay 2: disconnected
    PGM-FI main relay 2 4P socket No. 4: jumped to body ground
    PCM connector A (51P): disconnected
    Test point 1 PCM connector A (51P) No. 8 - Refer to:
    PCM Connector for Inputs and Outputs (6-Speed A/T) (2016 2017 2018 2019 2020) or
    PCM Connector for Inputs and Outputs (2016 2017 2018) .
    Test point 2 Body ground

    Is there continuity?

    YES 

    The IMOFLR wire is OK. Go to step 5.

    NO 

    Repair an open in the IMOFLR wire between PGM-FI main relay 2 and the PCM (A8).

  5. Determine possible failure area (PGM-FI main relay 2, others)

    -1. Remove the jumper wire from the PGM-FI main relay 2 4P socket.

    - 2. Reinstall PGM-FI main relay 2.

    - 3. Connect terminals A and B with a jumper wire.

    Terminal A PCM connector A (51P) No. 7 - Refer to:
    PCM Connector for Inputs and Outputs (6-Speed A/T) (2016 2017 2018 2019 2020) or
    PCM Connector for Inputs and Outputs (2016 2017 2018) .
    Terminal B Body ground

    - 4. Turn the vehicle to the ON mode.

    - 5. Measure the voltage between test points 1 and 2.

    Test condition Vehicle ON mode
    PCM connector A (51P): disconnected
    PCM connector A (51P) terminal No. 7: jumped to body ground
    Test point 1 PCM connector A (51P) No. 8 - Refer to:
    PCM Connector for Inputs and Outputs (6-Speed A/T) (2016 2017 2018 2019 2020) or
    PCM Connector for Inputs and Outputs (2016 2017 2018) .
    Test point 2 Body ground

    Is there battery voltage?

    YES 

    Go to step 6.

    NO 

    Replace PGM-FI main relay 2.

  6. PCM operation check

    -1. Turn the vehicle to the OFF (LOCK) mode.

    - 2. Remove PGM-FI main relay 2 (A) from the auxiliary under-hood fuse/relay box.

    GHH309410Courtesy of HONDA, U.S.A., INC.

    - 3. Remove the jumper wire from PCM connector A (51P).

    - 4. Reconnect PCM connector A (51P).

    - 5. Exit the SCS mode with the HDS.

    - 6. Turn the vehicle to the ON mode, and measure the voltage between test points 1 and 2.

    Test condition Within 2 seconds after turning vehicle to ON mode
    PGM-FI main relay 2: disconnected
    Test point 1 PGM-FI main relay 2 4P socket No. 3
    Test point 2 PGM-FI main relay 2 4P socket No. 4
    GHH309411Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    Check for any authorized service information related to the DTCs or symptoms you are troubleshooting or substitute a known-good PCM - Refer to:

    PCM - Removal and Installation (6-Speed A/T), ('16-'18 9-Speed A/T)

    NO 

    Go to step 7.

  7. Determine possible failure area (+B FUEL PUMP line, PGND line)

    -1. Turn the vehicle to the OFF (LOCK) mode.

    - 2. Reinstall PGM-FI main relay 2.

    - 3. Disconnect the following connector.

    Fuel tank unit 4P connector

    - 4. Turn the vehicle to the ON mode, and measure the voltage between test points 1 and 2.

    Test condition Within 2 seconds after turning vehicle to ON mode
    Fuel tank unit 4P connector: disconnected
    Test point 1 Fuel tank unit 4P connector No. 1
    Test point 2 Body ground
    GHH309412Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    Go to step 9.

    NO 

    Go to step 8.

  8. Open wire check (+B FUEL PUMP line)

    -1. Turn the vehicle to the OFF (LOCK) mode.

    - 2. Remove PGM-FI main relay 2 (A) from auxiliary under-hood fuse/relay box.

    GHH309413Courtesy of HONDA, U.S.A., INC.

    - 3. Connect terminals A and B with a jumper wire.

    Terminal A PGM-FI main relay 2 4P socket No. 1
    Terminal B PGM-FI main relay 2 4P socket No. 2
    GHH309414Courtesy of HONDA, U.S.A., INC.

    - 4. Turn the vehicle to the ON mode.

    - 5. Measure the voltage between test points 1 and 2.

    Test condition Vehicle ON mode
    Fuel tank unit 4P connector: disconnected
    PGM-FI main relay 2 : disconnected
    PGM-FI main relay 2 4P socket No. 1 and No. 2: jumped
    Test point 1 Fuel tank unit 4P connector No. 1
    Test point 2 Body ground
    GHH309415Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    The +B FUEL PUMP wire is OK. Replace PGM-FI main relay 2.

    NO 

    Repair an open in the +B FUEL PUMP wire between the auxiliary under-hood fuse/relay box and the fuel tank unit.

  9. Open wire check (PGND line)

    -1. Turn the vehicle to the OFF (LOCK) mode.

    - 2. Check for continuity between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    Fuel tank unit 4P connector: disconnected
    Test point 1 Fuel tank unit 4P connector No. 3
    Test point 2 Body ground
    GHH309416Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The PGND wire is OK. Replace the Fuel Tank Unit - Removal and Installation .

    NO 

    Repair an open in the PGND wire between the fuel tank unit and G602.

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