F430 E-Diff light off & on at times

Any one experiencing the same? Dealer said they could not duplicate it and since the exhaust is now a capristo stage 3 and have 20" wheels the warranty is void on the drive train and who knows what else is voided.

 

Sorry to hear about your warrenty issues. There was a post on here regarding that I beleive Rifledriver posted it. Ferrari is getting very sticky with aftermarket add on's. As far as the light goes...sorry I can't be of more help.

 

Sorry to hear that your warranty has been voided. Fitting aftermarket parts to a new car could be dangerous in terms of warranty.
I don't know much about these new E-diffs, but what I know is from my readings that minor changes in wheel weight, wheel diameter,..etc. could affect the electronics and computer governing the E-diff. Therefore, IMO I would not change anything in a stock car. Everything has been carefully calculated with very tight tolerances to provide you with the best and safest performance.

 

Hi Edward,
What size tires do you have on ?? if the aspect ratio is incorrect you will get E-diff, and ASR lights on at different times, depending on vehicle speed, steering input, load etc.
You know where I am if i can help in anyway, feel free to call.
Regards
Damian

 

You really want to believe what they told you? They want you to so, but your are foolish if you do.

Do you really think a dealer can abrigate a manufacturer's warranty?

Have you read your Ferrari warranty?

Don't buy into that garbage, and if you need a lawyer let me know!

 

I'm guessing your new wheel/tire combo has a different overall diameter than stock which can cause the problem.

Dave

 

235-30-20 in front
285-30-20 rear

Installers said it would be close to the original dimensions.

 

Those are very close to stock, but if you have the stock wheels and tires still I would put them back on for a while to be sure that's not the cause.

Dave

 

Great idea!

 

Edward
Those tire sizes are off. I dont think you can have an aspect ratio of 30 on both front and rear tires when the rears are so much wider.(unless you have a 19 on the front but even then)
The rolling radius of these tires is now different and is most likely your traction control issue. One of the 430's in the shop right now has 305-25-20 rear and 235-35-19 frt. I have a set of stock wheel/tires here if you need help.
I will check on tire sizes for you in the morning
and PM you.
Best
D

 

Very interesting. I don't I understand why this would happen. The aspect ratio speaks of the tire sidewall and I don't think is computed or a parameter in the E-diff/ASR programing. I would think E-diff and ASR will read faults when there is mismatch in overall diameter only left to right or if there are traction differences. I do not know how E-diff/ASR would know that the diameter is different than stock with two equal size aftermarket wheel/tire combos. This does not make sence to me from what I understand about traction control. Ediff/ASR works fine with racing slicks which have more grip and any sized street tire so I can't believe that you have E-diff/ASR triggering due to increased grip levels of wider street tires. Something does not compute to me.

 

Its because the rolling radius of the tires changes. The ASR/E-diff just work of wheel speed sensors. If the rear wheels are turning faster than the fronts it thinks they are spinning(slipping) so activates the traction control. changeing tire sizes can change the relative speed of the front verses the rear. It will not set a code because it does not see a fault in the wheel speed sensor, the c/u is getting a reading, they just dont match or fall within the specified variance allowed for wheel slip. 90% of traction control problems we have through the shop are tire/wheel size faults. On newer Benz's with electronic transmissions, I have see an odd tire size cause the transmission to shift incorrectly or miss gears. The rolling radius of the wheels must be withing the correct window, it has nothing to do with grip levels

 

Yes...does Ferrari or have you determined the tolerence for front to rear tire diameter mismatch in say % difference front to rear in rev/mile? Can you make any comment on the benefits or lack of benefits to extremely tight tolerences? C5 and later Vettes had one of the earliest production and best fuctioning active handling systems with sport car compromises yet a very wide tolerence allowing a wide range of tire diameters.

 

I dont have the tolerences, Ferrari (or any other manufacturer that i know of) dont release that sort of information. While driving the car, with the tester on in the actual values screen, you can watch the wheel speed of each individual wheel, as the speed increases watch for the light to come on and see what the relative speed of wheels are at that time and you would be able to determine an approximate differential. normally one tire size out (xxx/25/xx instead of xxx/30/xx) is enough to set the light on.

 

I must point out, if you switch CST off, then the E-Diff light should stay off, if the light remains on, then your problem may be deeper that already advised.

Best
Michael

 

I worked up the total diameters for his new wheel/tire combos and they were within a few milimeters. The stock tires also have the same aspect ratio front and rear (35). Stock is 225/35-19 front and 285/35-19 rear. The overall diameters in stock form is 640 mm front, 682 mm rear. His new combo is 649 mm front, 679 mm rear. On the rears in particular, tire wear variations would be greater than 3 mm.

Dave