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Engine P0125

Discussion in 'Powertrain' started by CDD, Oct 24, 2008.

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    CDD New Member

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    P0125

    Hi I got code P0 125 (Insufficient Coolant Temperature For Closed Loop Fuel Control )

    So my question is which is more likely to be the fault in a 01 Canadian S Rolla?

    # Leaking or stuck open thermostat?
    # Faulty coolant temperature sensor?

    Thanks for the tip :) . I already check the price on the thermostat is $19.00 OEM plus $4.50 for the gasket and $18.00 for the red coolant. I will have to check the price of that sensor :mad: just in case
    CDD, Oct 24, 2008
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    fishexpo101 Get Some

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    How many miles/kms are on the car?

    More that likely, it is a thermostat issue. Temperature sensors rarely just die - but the electrical connection might be a problem. Make sure the connectors are in good shape - no corrosion.
    fishexpo101, Oct 27, 2008
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    hellapinoy 2000 Celica GTS

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    you can test the sensor. not too sure how but it involves ohming it out from cool temp, then dunking it in hot water to see the readings change... theres a spec on those... not too sure what they are tho... theyre different per car. then ohm out the wires from the sensor to the ecu to check the continuity...

    it wont be the thermostat cuz if it was, you're car would have been overheating or it would take forever to get hot...

    tip, there COULD be 2 coolant temp sensors in the system, one is for the ecu input and the other for your gauge reading on the cluster...
    hellapinoy, Oct 27, 2008
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    JspeXAE102 Well-Known Member

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    I got that code before, it turned out my o2 sensor was unplugged.
    JspeXAE102, Oct 28, 2008
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    CDD New Member

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    Yep funny I got the answer from a OBII site here the web can be so trusted :wtf:

    So I just got my hand on a official Toyota Corolla Repair manual for a 01 Rolla like this one :rule: fresh from Ebay:D and its says it one of the following

    1. The ECM
    2. Check for open and short in harness and connector between ECM and heated oxygen sensor (bank 1sensor 1)
    3. Perform diagnosis for misfire.
    4.Check gas leakage on exhaust system
    5. Replace heated oxygen sensor (bank 1 sensor 1).


    So thanks for all your info :)
    CDD, Oct 28, 2008
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