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Q: Why is the check engine light always on?

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The Check Engine light in my 2006 Toyota Corolla (87k miles) always seems to be on for one reason or another. I had it serviced the first few times but now it just comes on with no difference in performance and no other warning lights. I am worried that if the light just stays on all the time for no reason then when something really does go wrong I won’t have any way to know. If there an easy way to find out why the light is always on without getting it serviced weekly?

You are correct that when the Check Engine light is illuminated with no drive symptoms you will not have any indicator if any more problems are happening. That is, unless another light comes on or you get symptoms you did not have before. I would first recommend you contact YourMechanic to have the Check Engine light diagnosed and resolve any issues the mechanic determines as a cause for the light to be on. If a code P0456 is present then Technical Service Bulletin(TSB) 0235 09 may be the cause. This TSB is an update to an earlier fix for your vehicle that you may have had done. This is a replacement or recalibration of the engine control module. A thorough diagnosis by YourMechanic can steer you in the right direction to fixing your vehicle so you won’t have to get it serviced weekly anymore.

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