Discussion in '80-Series Tech' started by landtoy80, Mar 2, 2004.

  1. landtoy80


    Likes Received:
    Mar 13, 2003
    North Front Range, CO
    EGR FA?
    71, P0401, P0402 Codes from the ECU

    Your check engine light is on and you have one of the Codes stored in you ECU.

    The EGR is a common problem with the FZJ80. The EGR system lets some exhaust gas, from the exhaust manifold, cycle back into the intake chamber to reduce emissions. This is good for the environment but not good for your motor.
    From what I have learned is that the modulator is the big problem. It is a diaphragm that is opened and closed via exhaust gas. It brakes down over time and lets carbon get into the vacuum system. Checking several times a year would be a good idea.
    These are some tip to get the EGR system working again.

    EGR=Exhaust Gas Recirculation
    Code 71=EGR System Malfunction
    P0401=Exhaust Gas Recirculation Flow Insufficient Detected
    P0402=Exhaust Gas Recirculation Flow Excessive Detected.
    FSM= Factory Service Manual
    ECU= the computer

    After every test, reset the ECU by removing the EFI fuse (in engine bay) for a
    several minutes.

    1) First check the modulator to see if carbon is in it. If so replace the modulator.
    If there was a lot of carbon in there you might need to replace or clean the vacuum hoses.
    Test the modulator per the FSM

    2) If your year has a temperature sensor remove it and clean the tip.

    3) Test the VSV per the FSM. The VSV is an electromagnet that opens and closes the vacuum in the vacuum system. If a chunk of carbon gets in the diaphragm it will make the VSV fail. It could if failed once, causing the CE light to come on but then the carbon
    could of gotten sucked out of it and test ok.
    To remove it for the first time it is best to remove the intake chamber as it is tight under there and the screws are tight. Do this when you clean the intake chamber.

    4) Test the EGR per the FSM. If your light has been on for a long time carbon could buildup so that the EGR can’t open and close.

    5) Clean the intake chamber. The port inside the intake chamber gets plugged with carbon to the point that it is almost plugged. You need to remove the intake chamber to clean it. It cleans up fine with carb. cleaner
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