Es35

2014 es350 with a bit over 5000 miles, today suddenly my malfunction indicator lamp and TRAC OFF lights both came on at once...need help what the causes may be since I can't get to the dealer until Monday. And is it still safe to drive the car???

lesz

Those lights could have come on for a multitude of reasons, and some of them could be as minor as having a gas cap with a faulty seal or not tightening the gas cap sufficiently, while other causes could be serious problems. Without knowing the malfunction codes, any thoughts about whether the issue is serious or not would be complete guesses.

For a good number of years, Toyota and Lexus have set up the malfunction indicators so that, when the check engine light comes on, other lights, such as the traction control indicator, also come on. I've heard differing opinions (even from service technicians) as to whether the other lights come on to make it harder for you to ignore that there is an issue or whether it means that there is actually a problem with the traction control system or whether, because of some other problem, the traction control system has been disabled.

Again, the only way to know for sure is to pull the codes from the OBD. Obviously, a dealer can do that, but most of the auto parts stores, like Advance Auto will have code scanners, and they will either pull the codes for you or let you use the scanners at no cost.

If you do go to an auto parts store and have the codes pulled, be sure to write down the numbers of the codes. Then, a simple internet search will tell you what those codes mean. After pulling the codes, you can clear them with the scanner. That will shut off the malfunction lights, and, if the cause was something simple, like a loose gas cap, those lights should not come back on. If they do come back on (sometimes not immediately), obviously, something needs to be fixed.

Also, for future reference, you would be able to pull the codes yourself if you get either the Carista smart phone app or Toyota TechStream software. The cost of either, including the app or software and necessary hardware is only about $20-30, and it allows you to know what the problems are without having to go somewhere else to have someone pull the codes.

jollick

Did you check the TRAC Off button to see if it is off or on?

dchar

If that was the case, restarting the car would automatically turn TC/VSC back on.

Es35

Update: drove my car in yesterday(Monday), got it back today(Tuesday). It was "poor fuel quality" that caused the engine light to come on, which was surprising and disappointing to me considering that since the day I got my car until now(a bit more than half a year), I went to the same gas station by Wher I live( Marathon). Now, i am curious on what gas(BP?) and what grade( regular?premium?) of gas you guys use for your lexus. Appreciate for all the inputs!

dchar

Hmmm...that's interesting. I've been filling up with regular on our ES350, but only at top-tier gas stations (76, Chevron, Shell, Mobil, Costco). Not sure if Marathon is top-tier, but I didn't think it would make that much of a difference. Maybe they have dirty filters and don't change them often enough. Putting anything more than regular would be a waste of money because there would be no benefits (performance or fuel economy) by using anything higher than what is stated.

Mike728

I'm guessing the gas cap was loose and they wanted it to sound more technical.

lesz

I concur. I'm more than a bit skeptical about the dealer's diagnosis of "bad gas". Poor gas quality (relative to what today's vehicles require) is pretty rare, and the relatively low compression ratios of the engines in the ES should be very tolerant of a wide range of fuels. Even with my GX, for which premium fuel is "recommended", I've never had an issue running with 87 octane fuel.

What is nice about being able to pull the codes yourself is that doing so gives you a degree of protection from any BS that the dealership's service department might otherwise give you.

Es35

So today, the engine light came back on again...going to bring the car in tomorrow morining, most likely they will tell me it's the gas again, if so, should I ask them to drain the old gas that is in the tank completely?

gemini6kl

I can say for a fact that gas quality varies alot from dealer to dealer and brand to brand . I have definately noticed different things when i purchase from the cheapest non branded gas stations, some isssues would be the car seemed a little more sluggish and also gas mileage or mpg went down a gallon or 2. since then i only stick to the 4 or 5 major brands.

lesz

I would suggest, before taking it back to the dealer, that you pull the codes yourself or have the guys at one of the auto parts stores use their scanner to do it. That way, if you have the codes and do a Google search to find out what they mean, there is less of a chance that the dealer will be able, for their own expedience, to give you a BS answer as to what the cause of the problem might be.

lesz

Regardless of whether there might be quality differences between the gas sold at some stations and that sold at other stations, while those quality differences might result in (minor) differences in fuel economy and performance, the gas sold by any station should not be "bad enough" to be causing the check engine light to come on.

Also, I've watched the tanker trucks pull into a BP or Shell station to fill the station's tanks and, then, drive down the road and fill the tanks of one of the no-name stations. In that case, it is hard for me to understand how the gas at the no-name station is any different from that at the Shell or BP station, not withstanding the advertising done by Shell or BP to try to convince you otherwise.

In any case, I am skeptical about whether the cause of the OP's problems is, in fact, "bad gas". That is why it would be good for him or her to have the codes pulled before taking it back to the dealer.