c3_dk

Hi,

I have a friend that just bought a 1998 Corvette, with F45 selective suspension.
It seams like the suspension is stock in one position.

What is the most likely mistake here, shocks, sensor or ECU?
How do I find out, what is wrong with it?

Thx,
John

c3_dk

Update.

The car can drive more then 80mph, and there are no error code in the display.

K-Spaz

I have no experience with these whatsoever but I would guess that Diagnostics on it would start by using a Tech 2. You can buy them on Alibaba if you can't find someone who has one. Current price is about $280 us.

johnson-rod

WHOA!! Before you start throwing money at the car try this; Reboot it.

I have the F45 and I like it. Tour is wallowy, Sport is taut. Perf is crazy hard. It's a subtle change but it's there. I can't run Perf on normal roads in winter. Too hard.
Runflat tires mask the settings. They make everything seem hard. You'll notice the differences more with softer tires or non-runflats.

To reboot the car, disconnect the battery. Negative terminal is safest. Wait about 10 minutes (or overnight) and plug it back in again. Be sure you have the radio code if that is set. It should remember everything else but the time and radio stations. All the car's systems reset (hvac/fobs/fuel trim and idle/) and I've always felt the suspension reacted better for a while. Remember the system is adjusting several times a second based upon info from the computers, speed, suspension reaction. I think it just ties itself up in knots after a while and needs to go back to factory original settings.

Bill Curlee

The very FIRST thing that you should do is read all the DTCs that are stored in the DIC. Its easy. If there are any errors or problems with the handling system, it will show you there. Once you have that info, we can help you from there.

Like Johnson-Rod stated,, the changes in the cars handling between each setting are very subtle. It could be working and you not know it. My wife could NOT tell the difference between any of the settings. I could tell the difference BUT it wasn't as aggressive as I would have liked it. If you drive ANY C5 with a dedicated handling package Z-51, ZO6 or any aftermarket springs and swaybars, you will see the difference NIGHT & DAY!

How many miles are on your F-45 shocks???????

Unlike Johnson-Rod, I had the F-45 system in my 98 coupe and absolutely hated it. ALL C5 with that system have the C5 BASE FE-1 springs and sway bars. SO, you are NOT going to get any aggressive handling awards.

Bill

c3_dk

THANKS I will tell my friend
I hope he has the code for the radio :- )

Hi Bill,

The car has 120.000km = 75.000 miles on it.
I've heard may say, like you do, that it's a crap system.

And I'm just thinking, is it working, but he can't fell the difference?
Maybe that is, what it is !

But I will tell him about the re-set, and tell him what is said here.
Thx both

/John

SDVette

80K miles on my 98 with F45. Never had a F45-related code (knock on wood).
Bill is right.. Runflat tires completely mask the subtle effect of this option.
With standard tires you can feel it much easier.
I also upgraded to Z06 swaybars and end-links.. Easy and cheap upgrade... This helps the F45 quite a bit.

jackthelad

Don't agree that RF's mask this option. Where you notice the difference, and a good measure of whether the F45 is working properly, is to find a bit of road with a "ripple", where cars usually do a couple of bounces as they go over it. In "tour" you will bounce like any other car; in Sport there will be less jiggling, and Perf should stop any secondary movement completely. I have 79k on mine, and that's how they behave. Mostly I leave it in "tour" to deal with crappy roads, but there are a couple of roads I use often where I crank it up to kill the after-bump bouncing.

I've run multiple brands of RF tires - none of them have masked the F45 functionality. Of course, if the shocks are shot, all you will have is a soft "tour" option.

SDVette

I didn't intend to bash on runflats.. they do what they were designed for.

I ran non-runflats for 10 years because the sidewalls are so brutally hard. They actually had to soften the C5 suspension to compensate for how stiff the Goodyear Eagles were. I understand some of the other mfgs were slightly softer.

Non runflats provide superior handling and grip... but if you get a flat, you better be prepared.

I actually swapped back to run flats (Michelin's now) because I don't want to screw with compressors, goop, etc.
But they are still pretty hard. If you drive a C5 with non-runflats, I think you would agree.

jackthelad

I use RF's for the same reason you do. And I do alot of driving on busy highways, where you really do not want to be working on the shoulder, as some sleepy soul will likely take you out. With RF's at least you can get to the next exit before attempting a plug, using the compressor or whatever.

johnson-rod

I went the other way around. When I absolutely positively had to show up at the office clean and on time I ran runflats.

When I retired I switched to non-runflats.

SDVette

Yes I can see the logic in that too.
For me, I used to do track days with the car. That is really when you realize what you give up for the run-flat convenience.