Q: Why is the check engine light always on?

asked by on

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.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. Why is the check engine light always on?

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: On slow moving traffic, when i release the brakes, the car has lags for half a second before take off... computer scan shows p2138

This code is related to a faulty throttle position sensor. The throttle position sensor (TPS) is a sensor used to monitor the throttle position of a vehicle. The sensor is usually located on the butterfly spindle/shaft so that it can...

Q: sudden loss of coolant

Hi Felicity. Thanks for sending in your question today. Assuming that your Chrysler 300 did not overheat previously and coolant is leaking internally, it's quite possible that your radiator cap has failed. This will cause coolant to escape in the...

Q: Recommendation on buying an old Toyota

Yes, I got rid of mine a couple of years ago. It was a Toyota Corolla SR5. That sucker had 350,000 miles and a 5-speed tranny. It ran like a clock. It's rusted now because they didn't put zip primer...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.