I think Larrychery makes some excellent points. We bought our 2012 350c new, and have had no issues with the top or anything else in 12 years. Granted the car only has 45K miles on it, but here in Southern California you can use the top pretty much year round. Most of our driving is around town, errands, groceries, etc, so the top goes up and down a fair amount - those black seats get pretty toasty sitting in the sun otherwise... We also had an SC430 for 8 years and 100K miles, no issues with the top either. Nothing is ever 100% perfect, but I figure if this were a really common issue, you would see a lot more postings on it and somebody would have come up with a solution they would sell...
I also agree on the 350c over the 250c. Even without the carbon fouling issue, the driving experience is just much better in the 350. I don't go racing around town or anything, but it is nice to have a car that can move if you have to pull out in traffic or find yourself in the wrong lane... The 250c we test drove back in the day was just sluggish and not that much fun...

 

Axel:
Thanks for your response... given what I have heard here, I would (now) choose a 350C over a 250C, as it appears that the carbon fouling issue identified with the 2.5L engine (due to Direct Injection?) probably outweighs the slightly better fuel mileage offered by the 250C-- but I am relatively unconcerned about the relative performance aspects of the two cars-- my wife just doesn't have much inclination to race around town (especially on the congested urban roads where she would mostly be driving it)...

I am concerned about this carbon fouling issue-- I had not heard about it before--and I did not find anything, when doing a search on this forum, for discussions related to it... I do not really understand why the 2.5L motor (which apparently uses direct injection-- which, when it came out, I thought was deemed a major improvement in fuel injection technology) is somehow more prone to carbon fouling than the 3.5L motor-- what injection technology does the 3.5L motor use?

And, more importantly, are there any precautionary or preventative measures that I can take to avoid getting carbon fouling with the 2.5L motor? Perhaps using certain brands of gas, over others (e.g.- Shell over Costco, or some such)? Or using some kind of fuel additive/cleaner (e.g.- STP) on some recurring basis? Or some regular maintenance action at a repair shop? Or possibly even avoiding certain driving habits (e.g.- lugging the engine, or lag throttle)?

I am very surprised that Lexus did not address this problem (as they apparently did with the so-called "melting dashboard" issue) over the course of the IS250C's production run... I don't really have an obvious IS350C candidate vehicle to buy, that meets our desired purchase parameters (i.e.- low mileage, very good/excellent condition)-- so I am currently inclined to buy the IS250C on which I had been focusing, and trying to avoid inducing the carbon fouling problem, through other means...

Perhaps that is simply not possible?

 

A quick Google search of "Lexus IS 250 Carbon" will show you plenty of results of people documenting the issue both from the IS 250 Club Lexus forum along with many other Lexus websites. Lexus I believe also issued a service bulletin related to the engine issue. It is not just limited to the C model, it affects all IS 250 models, including the convertible. The solution to the problem, as reported by many is to drive the car "hard" a few times a week minimum, hitting redline over and over. That clears out the built up carbon for the car. Not a real solution in my book since all you have to do is forget about that for awhile to run into (what can be) a very expensive repair. Personally, I'd just stay away from a car that has a major known issue like this, when like you said - the MPG difference is hardly anything and that the IS350/c don't have that problem at all (or any other known major engine problems that I am aware of).

The 350c will hold its value better than the 250c, something else to consider. I was able to get my 350c, 100% dealer maintained, at 95,000 miles for $18,000. I wasn't concerned with "low mileage" as much as I wanted a strong chart of service records and a singular owner. Also something else - low mileage isn't as much of a concern for this particular type of Lexus. The issue I've noticed with my 2010 IS350c is the wear the sun has had on it over 14 years. If I had to redo my pick, I'd get the last model year possible at any mileage. The sun does a number on the interior if you don't use protective products religiously. Mine's not in bad shape, but the steering wheel and side arms of the seats are pretty badly sun beaten. Considering having the leather redone on those portions.

 

hello, that warning light is annoying. the cheapest and easy way to get the top computer to reset is to unplug the battery overnight. this will reset the system and remove the error as long as all your sensors are in order!
good luck

 

the convertible top was tested 30 thousand times at the factory before release. they are reliable as long as nothing gets stuck or jams one of the 37 sensors. most top issues are caused by accidents warping the frame causing a sensor to be crushed. as far as the carbon buildup rev engine getting on highway once a week. you can also spray carbon valve cleaner into a vacuum line in the intake manifold before every oil change while the engine is revved at 3k rpm. if you start getting cam chatter from the buildup. usually around 180k 200k miles rev engine 3k rpm for 3min in neutral. or clean out the carbon with a wire brush. sorry for grammar i am on the spectrum.

 

Going to toss this out there as a guess - if it's doing OP SUSPENDED after it's fully closed, it's likely one of the last close sensors is malfunctioning.

My 2 cents of advice - have someone go stand behind the trunk and press down HARD where the trunk meets the roof. See if that causes the error to go away or at least maybe see if the message switches to COMPLETE.

 

hey brother ive got a lexus is350 with the left side package tray switch coming up as rhe fault, we have got a new package tray and want to change it, is there a service procedure u have or procedure to change it that u could send me if u have one, we have never change one on this model, thank you, i couldnt message u so had to reply here

 

I purchased 3 microswitches from the link provided here,they are different than the ones i was replacing, the alignment pin and bolthole are frther apart than stock. Theydo fit in other locations just not on the one i needed. The half cent piece of metal that actuates was missing on one, repaired and rewired 2 after they tested good,
and 200 dollars worth of hinge assemblies to rob switches,, that didnt work. I am trying to find a mobile mechanic with techstream software that can interface with ECU for top and tell me which one it is. If anyone knows of one in Dallas area PLEASE LET ME KNOW

 

Hey just checking to see if you were able to get the left side package tray switched out I need to switch out mine as well, and if someone could send over the service manual that would be great.

 

Hi all

The weather stripping on the package tray slipped and got wedged between the bottom of the tray and one of the folded down roof pieces.

I was able to remove the weather stripping but the top won’t continue operation up or down.

When I attempt to operate, the package tray makes a small movement before stopping and I get the operation suspended notice.

I am not mechanically inclined outside of brake jobs and oil changes. Any ideas or should I bite the bullet and take it to the dealership?

 

THIS WORKED👍🏽
option 2 disconnect battery for 15min, hold down trunk unlock button on keyfob while reattaching battery.

 

Great thread, thanks. Does anyone have any guidance on maintaining the open/close hardware for the convertible? What I mean is, are there maintenance oils, greases, etc., that should be applied at interval. Any information would be helpful. Thank you!

 

@pjoeltyler Did any of the ideas here work?

 

Mine does the same roof closed runs drives great had the dealer tech stream it, no codes or history of codes but when it’s colder out, 60 or below it shows up. After the day warms oh around 70 get in start it code flashing hit close and it’s gone. If I start and try that same action it never goes away when it’s 50 or below. Weird. Glad I live in Florida 😎

 

To manually close the hard top the user manual has a 25+ step emergency process you can follow

where i can find those steps ?