When you turn the key to the run position, the check engine light should come on. When you start the engine, the light should go out within a few seconds of startup.


If your light does not come on, and you have emissions inspections in your state, your Avalon will not pass the inspection for your plates.

 

thank you very much for your answer already must turn on the check engine when the car will start. mine does not, as could verify that the sensor is not disconnected or which is not blown bulb ?, thank you very much

 

I am confused as to what you are asking. I will presume that your check engine light does not come on when the key is in the run position with the engine not running. This could be a bulb/led, connection, PCM, or a fuse. Without having the car, I can only guess.


This is not a common issue with most vehicles unless someone took the bulb/led out.

 

That was exactly what I was asking a friend, perhaps as I do not speak much English and use a translator question was not written in the best way. It is certainly not very common that problem, but I suspect someone disconnected the LED on the engine check, because I buy that used car and when I first had led the check engine on and the owner told me that it was because he needed oil change and then took him to change the oil and when I return and the LED does not turn on, maybe it did was it disconnected. if you know where that led connection would appreciate to tell me and what steps I need to do to change the led ?. thank you very much for all your help, it has been very useful for me

 

Your English is much much better than any attempt of mine to converse with you in your native language. :smile:


Without removing the instrument cluster I have no idea if it is a bulb or LED. I would assume it is an LED because most vehicles I have worked on lately use more LEDs in their clusters than bulbs.


Perhaps someone removed the bulb or cut the wire to the instrument cluster that turns the bulb on at the last oil change.


Now, for a different idea, could it be that the Maintenance Required light was on because it was due for an oil change, and they turned the light out as they should after the required maintenance was performed?


The check engine light should be a pictogram showing the side view of an engine. It should come on with the key on and go out when the engine starts.




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hello friend thank you very much for all your replies. I think the oil change was not what made the LED will turn off the check engine, because if it had been that I would still be going on when I put the key in position. I would like to do some testing to see if the check engine works not whether to start the car without fuel tank cap or if there otherwise. The other thing I want to know is what are the steps to remove the Dashboard, to check the cable connection and led the engine check. thank you very much all over again

 

Now I understand. When you have the key on, and the engine is not running, the check engine light is not on.


Before you go to a lot of unnecessary work, let's test the fuses first.


Checking the wiring diagram, there are three fuses for this circuit.


7.5 amp DOME fuse (located in the left side instrument panel fuse box)


10 amp ECU-B fuse (may also be labeled ECU-IGN No.2 (located in the left side instrument panel fuse box)


7.5 amp GAUGE NO. 2 fuse - located in under hood fuse box


Check these three fuses carefully. Don't just remove them and look at them. I prefer to check fuses with a test light.


Let me know.

 

Hello thank you very much for your answers. I was reviewing the manual and 7.5 amp fuses DOME 10 amp fuse and fuse ECU-B are located in under hood fuse box and 7.5 amp GAUGE NO. 2 fuse on the left side instrument panel fuse box. I imagine it was a confusion but do not worry I understood perfectly, I only say this to verify that all this good.
Tomorrow morning I will review these fuses and check that they are good, or I will try to remove the dashboard to check that the LED is good. thank you very much for everything, then I say if everything went well.

 

My friend finally solve the problem of check engine LED. I did everything you told me and it was no fuse, everything was in perfect condition. I disassemble the dashboard had to remove several plastic parts panel to reach that. When checking the LEDs all were well, what happened was that they put a tape in front of the LED to shine no, not the symbol check engine ignition see. It was all a lie that had gone after the oil change, the truth was that covered the LED with black tape to avoid Ciera Power on the board. I suspected that led was not working because I put the OBD2 scanner and I said there were problems with the P0300, P0171 and P0174 and the check engine LED was not lit and these problems should be on. Now if on all the time after you remove the piece of tape that had been placed. I was going crazy looking for what the problem was and that turned out to be the problem. Now I have to fix the problems that led to the check engine is turned off. Thank you very much for all your help and for all his advice was very useful for me. A big hug from a Cuban from Miami FL.

 

they put a tape in front of the LED

Now we can investigate your fault codes.


The P0300 is a misfire, but usually you will have a specific cylinder like P0305 so narrowing that down is another issue.


The P0171 and P0174 are both lean codes, usually meaning there is a vacuum leak. Since you have codes for both banks of the engine, something that both banks share is the culprit.


Check the air intake duct between the air cleaner and the throttle body. Look for any loose vacuum hoses. The MAF sensor could be dirty, if the air filter has not been replaced as needed, or if an inferior filter is allowing dirt into the engine.


I would need to see some scanner data to really dig into this. Diagnosing over the Internet is difficult, as you can see.

 

thank you very much, I will review everything you told me to see if the problem is solved. Wednesday is my day off and I'll try to solve those problems that my car. Then I tell him if I could fix something

 

Hello again friend, this morning cleaning the air mass flow sensor with a special liquid for that and then put back. then I put the scanner in the car and gave the same code and then delete it and turn off the check engine. I've gone about 20 miles and has not been rekindled, I will continue attentive to see what happens. Thank you very much for all your help.

 

Would the light have come on that soon after clearing the code? I never get excited because the light decided to stay out after my repair. If the light is still out in 2 weeks, then the issue is probably gone.

 

My friend the light has not turned on back after it was turned off, and tomorrow two weeks trailed off and I have traveled more than 150 miles and all is well done. Now I have better average miles per gallon, the other thing I want to do is to change the spark plugs the next week, thanks for everything, greetings

 

Great news!


A couple of suggestions about the tune-up :


1) Use only DENSO iridium spark plugs.


2) If you can afford it, replace all three ignition coils in the rear. These are difficult to replace, and have a history of failing. DENSO makes these coils also. Keep the old coils for when one of the front coils fails.


Cheap aftermarket parts are available, but you get what you pay for.

 

I have genuine Denso spark plugs and also the gasket, only need to buy to replace the coils 3 back as you told me. Like always I use genuine parts, thanks for the help

 

My friend I replace the spark plugs in my car perfectly, now everything is good, the check engine never turn on again. Thanks for you help.

 

Great news! You are welcome. I am glad to help when it is appreciated.