I am a happy vette owner today. After a week of trying to deprogram the F55 suspension on my 2003 corvette I finally succeed!

SIMULATORS DO NOT WORK ON THE 2003 AND YOU WILL SPEND FROM $159 TO OVER $200 FOR A SET OF EIGHT. CRAZY!!!!

After installing Pdaft inverted shocks the dreaded "Max speed 80 MPH Flash on. After endless calls, three dealers and GM saying it can't be done, you need to replace your shocks with the F55 suspension, it is finallly solved.

Here is the procedure that worked!

1. Hook up your Tech 2, turn the car ON, make sure the module in the rear is plugged in. DO NOT UNPLUG THIS MODULE

2. Now use the Tech 2 to delete the F45 option ( F55 option does not appear on the Tech 2 menu screen - SO - DELETE THE F45 OPTION

3. Save the new configuration

4. DO NOT TURN THE CAR OFF DO NOT REMOVE THE TECH 2 Go to the module in the rear of the car, unplug the GRAY connector - IT IS THE WIDEST ONE - leave the center and smaller black plug in.

5. Turn off the car but LEAVE THE TECH 2 PLUGGED IN

6. Remove remaining plugs from module in the rear of the car

6a Disconnect battery for at least 60 minutes

6b Reconnect battery

7. Now the moment of TRUTH - Turn the car on and verify that the dreaded - MAX SPEED 80 MPH - is gone

8. Unplug the Tech 2 - Get in the car and take it for a ride. Smile as you pass the DREADED 80 MPH and in knowing that you beat GM

Hope this save all time, money and frustration - this process can be completed in about 15 minutes so it is much less expensive than simulators. DO ME A FAVOR - DON'T GO TO A DEALER - SPEND YOUR MONEY WITH A LOCAL SHOP.

 

What is so hard about the C5 F-45 and F-55 Delete? We have been doing that for years on '98-'04's. The C6 is the hard one.

 

I tried this today and had no luck does anyone have any other ways to turn of the F55 shocks. I have a 2004 c5 with the f55 option. I took the shocks off and put on 2008 c6 z06 shocks.

 

I agree. Try again and make sure you follow sequence exactly. You may also disconnect and reconnect battery after sequence has been completed.

If this doesn't work: There is another way and I will try and post today. It has to do with some simple wiring to fool the computer into thinking the F-55 shocks are still being used. The parts can be purchased at Radio Shack and are very inexpensive.

I have heard that the sequence I posted has not worked on some cars but always contributed it to not following the instructions.

 

When F45 Shocks are removed:

You DO NOT need anything turned off, removed, retuned or modified. You need 4 10 ohm 10 watt wire wound resistors ( from radio shack) to solder in to the wires that go to the top of the old F45 shocks. Solder them the in , zip tie them to the chassis out of the way and install the new shocks That's it.Garanteed.

Found this on this board quite awhile back-not positive the ohm/watt values are the same for F55,but the parts are only a few bucks,wouldn't hurt to try....

 

That's the same information I was talking about. Was told it works every time and it is inexpensive and quick solution.

 

Contact Ed Hutchings at Virginia Speed.

 

that is the correct proceedure and the correct resistor size. I've done this mod on 3 differerent Vetts , the first one 3 years ago, and have never had any subsequent problems. Now tha's for the F45 option, I have never done an F55 car.

 

Is there a trick to this delete thing. I tried another corvette place a few weeks ago and still can't remove the codes or go above 80 mph. The Dash computer wil show the shock computer gone and remove it from the options but something in the car still has the 80mph max thing stuck. We cleared all the codes on the tech II. Is there something else we should be doing to clear everything. I followed this procedure to a t many times in many different variations without any luck. Does the PCM have a way of remembering the shock missing code someway and need to be reset?? And if so how can you reset the PCM. I have gone through and reset the codes in the dash.

 

Excellent work!!! Very useful post!!

BC

 

Figured it out today. The above procedure is missing one thing. You need to unplug your batterey for long enough for your engine computer to reset. Otherwise the 80 max is stil in the engine computer I am guessing. I tried right after and could only do 80 mph. I unpluged my batterey to the car for about 3 hours or so and after the reprogram. After this the max 80 mph was gone and I could drive as fast as I wanted.

 

Could you not have achieved the same result by manually resetting the codes in the DIC?

 

tried to manualy do it but there was nothing to remove. One of my coworkers has the exact same car and he had to unpluc his battery overnight to get the 80 mph max to clear.

 

I have a 2004 Commerative with the F55 suspension on my 2nd set of simulators. Should I try the 4 10 OHM 10 watt wire wound resistors first? or the tech II? Come on I bought the car to go over 80 mph, specially when my wifes CTS beat me.

 

Thanks. Anything else I should know?

 

after your finished make sure you disconnect the battery for 30 minutes.

 

So here is another dumb question. What are you using to cap the plug? Since there is nothing plugged into it now. Thanks

 

If your F55 shocks are bad, just cut the connectors off them and plug them into matching connector left on car.

 

I have replaced the shocks with new ones. So I just just leave the one end plugged in and cut off the other end?

 

Just got mine done at a dealership in Conyers GA after telling them they can do it. I was supposed to get it done in Louisiana and they were all to happy to do since they had done it before. I was maybe at the stealership maybe 30 minutes and it was done. Service manager says the I have to keep the wires unplugged in the back to stay good. I just say okay thinking that is not what I have read before. Turn on the car, 80 mph limit message is gone and only my passenger DRL quit working on me.🤷‍♂️ Of course now my driver side window will not go all the way down, I have a neutral safety switch code and something about my abs. Anyone know if I unplug the mechanism that attaches to the upper A arm will that throw an abs code?