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Car has 463 miles. Driving on the interstate this morning and while going up the exit ramp, the check engine light, Trac Off and Visis your dealer lights all come on. Now also when I brake, the engine downshifts weird. I filled up with gas yesterday (93 octane), and made sure the cap was on tight.
Any ideas? Car still runs and everything, but it definitely idols more rough now.
A CEL that shows up shortly after getting gas is most likely a gas cap issue - especially with the current weather.
Remove the gas cap and put it back on. After several starts the code will most likely go away.
A faster way is to remove and replace the gas cap, then go to Autozone/PepBoys/O'Reilly etc. and have them read (write down the code) and clear the code. They'll do that for free.
If the code stays away then it was the gas cap.
Any of the O2 sensor/gas cap etc. codes will turn VSC off and may cause rough idling or stumbling (ask me how I know)
You'll want the actual code should the error return after Autozone clears it - if nothing else to compare that code to the new one.
Given the age of the car (not very) and the fact that you just gassed up, I'm 99.9999% positive that it was a gas cap issue.
Tightening the cap with an error doesn't work. You need to remove the cap and put it back. Make sure that there isn't any debris on the rubber seal.
I don’t think it is just the gas cap loosing issue. For gas cap related, it won’t trigger the Tack off light, and it won’t causing rough idle either. It has to related to emission system, most likely the one or more sensors malfunction or lose connection. The DTC code will directly indicate which one may have the problem. Since it’s a new GX, the best action is to take to dealer.
I don’t think it is just the gas cap loosing issue. For gas cap related, it won’t trigger the Tack off light, and it won’t causing rough idle either. It has to related to emission system, most likely the one or more sensors malfunction or lose connection. The DTC code will directly indicate which one may have the problem. Since it’s a new GX, the best action is to take to dealer.
Frequently, when my sister fills up my mom's RX, we get the CEL and the VSC off lights come on. It will often idle roughly.
I'll be interested in seeing what the dealer says.
Taking it to the dealer first thing tomorrow morning. I will let you all know what they say.
Just to cover some bases. I did remove the gas cap and re-retighten (to click) after I got to my destination this morning. It sat in the parking lot for 4 hours before I restarted it. I drove it back home via the interstate (about 25 miles). The lights are still on, but the rough idling did not occur on the ride home.
Friend of mine said they’ll likely just reflash the ECU and it’s not a big deal. It is to me, of course, but we’ll see.
Good game plan. Usually if its the cap you`ll see it go out in a couple drive cycles granted this driving occurs between 3/4 and 1/4 tank. But either way 500 miles and a CEL is still a thing the dealer should be checking just in case.
Sidenote
For piece of mind, I`d grab a cheapo OBD bluetooth/wifi scanner so you can plug into your car and grab those troublecodes right on your phone. The CEL is such a poorly thought out idea. With 2 screens in the vehicle, would it hurt to simply display those trouble codes and maybe a section map of the associated issue (p01234 check fuel system). Its not a Lexus only thing, OBD2 need a refresh in general.
Taking it to the dealer first thing tomorrow morning. I will let you all know what they say.
Just to cover some bases. I did remove the gas cap and re-retighten (to click) after I got to my destination this morning. It sat in the parking lot for 4 hours before I restarted it. I drove it back home via the interstate (about 25 miles). The lights are still on, but the rough idling did not occur on the ride home.
Friend of mine said they’ll likely just reflash the ECU and it’s not a big deal. It is to me, of course, but we’ll see.
A good rule of thumb is at least 3 clicks. It is usually a handful of start cycles before it resets by itself.
You didn't top off the tank after the pump shut off, did you?
Let's hope that all the dealer needs to do is read and reset the code.
I topped it off, but not much. It only allows 1 click. It has been very hot here, so potentially too much gas was added. I drove 50+ miles today, so it’s not full anymore.
I topped it off, but not much. It only allows 1 click. It has been very hot here, so potentially too much gas was added. I drove 50+ miles today, so it’s not full anymore.
The problem with topping off (especially in hot weather) is that gas can get into the evap canister. In simple terms, the canister is intended to keep gasoline vapors from escaping into the atmosphere and are effectively "recycled" back into the tank.
If you overfill the tank (either by topping off or by expansion on a hot day), then the canister gets saturated. This will also throw a CEL but isn't a easy "clear and drive away" as the canister may need to be replaced.
If, however, you merely filled up, topped it off a bit only to make sure that the tank was actually "full", and drove the car for at least 10 miles or so (so a half gallon of gas plus) then you should be OK. IIRC, gas expands about 1% for every 10 degrees. The gas coming out of the pump is about 55-60 degrees and the car in your tank can easily reach 100-120 degrees if it is 90 degrees outside. The tank holds 23 gallons. Accordingly, the gas could expand by over a gallon, so enough to overflow the filler pipe and contaminate the canister.
07-19-20, 04:52 AM
2020 GX check engine light
