Rx300 Check Engine Light.. Codes?

[rossim22]

I'm sorry.. but I'm new. Could somebody please give me a detailed instruction on how to check for codes. Please describe everything as if you were talking to a 4 year old.

[thunderbirl]

It's not possible to do this without an electronic device that understands communication protocols and can interrogate the "on board computer".

However, in my area, at both AutoZone and Action Auto Parts, the counter person will take their device from behind the counter and come out to the parking lot to read out the codes for free. You drive over, you ask politely, they tell you what the codes are - just that simple.

The tough part is taking that data and figuring out what the problem is. In one recent case, the malfunction caused the computer to try to correct for the condition by adjusting the fuel mixtures rich and then lean on each of the cylinder banks. This caused the car to misfire on multiple cyliders and gave out a bunch of codes. I had to clear the codes, run the car briefly, find out what the initial code was then sit and think about the things that could have caused that to happen. Whether a local auto parts store will read out your codes twice may depend on you having a good relationship with the folks at the couter!

Sometimes, the counter person will only give you the code and not what it means (it may depend on the sophistication of the scanner they use!). A valuable resource for what it all means is at http://www.obd-codes.com/trouble_codes/. Be sure to look first at the generic codes at the bottom of the page and then up at the top half of the page under Lexus.

Of course, you can always buy your own scanner! I bought a modest unit and it paid for itself with just one use.

Hope that helps.