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Thread: Trouble Codes

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    Default Trouble Codes



    Not necessarily 4x4 but I imagine it's the same regardless. Please explain why a problem indicated by an error code disappears when the code is cleared.

    Barb's Accord threw 3 codes when her transmission started acting up badly after an ill-advised flush. A transmission shop cleared the codes and now all's well. They say an external sensor is the first thing to fix to try to solve the problem but also said it may behave for quite a while. They cleared the codes and it's fine.

    My understanding is the error sends bad info to the computer. Clearing it removes that info and now the computer is sending correct info and eliminated the problem until it's triggered.

    Clearing the code stopped serious slipping.
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    Chris in Florida

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    Default Re: Trouble Codes



    The way I understand it, is a sensor or problem will send that problem to the ECU - it will kick on the CEL and if you clear it and the problem is still there, the CEL will just come back on again. If you fix the problem and clear the codes, the CEL won't come back on.

    There are instances where probably the presence of a certain code will cause the ECU to make a component enter a "safety" mode as to prevent damage, which may not go away until the codes are cleared.

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    Default Re: Trouble Codes



    Oftentimes a code puts the entire car into "limp" mode. That is likely what happened. Something with the trans flush may have caused the code to trigger, and the computer defaults into the limp mode. Not sure what the rationale is behind it.

    Same thing happened with one of our Miata's. It has 2 cats, one of which had gone bad, and the O2 sensor was reading a slightly high HydroCarbon reading. It then sets a code, check engine light comes on, and it goes into the limp mode. Limp mode in this scenario is DUMP fuel into the cylinders. Like that is BETTER than the original problem. Just by reseting the code, the car passed an e-test. In limp mode with the light flashing, you wouldn't want to drive behind it. Smelled horrible! Absolutely the opposite of what seems rationale!

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