I picked up my 2004 Roadster at the end of May. When I test drove it at the dealership, the TCS came on twice. I was pretty surprised because I wasn't in a situation where I felt it should have kicked in. I took the car home because I couldn't wait any longer to have my new Z. After a couple of months of driving I now know that it definitely does come on at times when it shouldn't. I switch it off most of the time when I drive now. The problem is the dealer has looked at it twice and can't find anything wrong. Since it's intermittent they also haven't been able to recreate it while test driving. Anyone have any similar problems or suggestions?

 

First I've seen of this issue. No problems with mine. I don't think it has ever kicked in.

 

Mine has come on a handful of times (4 or 5) when I think it probably should have. I like to drive it the way it was meant to be driven and know I can shut TCS off when I need to. I've probably had it happen 20 or 30 times in the 3 months I've had the car. Something is not right.

 

what are the time you think it shouldnt come on when it does?

whats happening:?

 

Many times.......in a gradual curve...dry pavement...doing the speed limit. The most obvious was changing lanes on the highway to pass. Was doing about 70 in 6th gear and moved left and accelerated while still in 6th. It did not make an aggressive move to the left nor did I mash the gas, but the TCS came on. Sometimes it does it while accelerating from a standstill. Again, not jumping on the gas or anything to induce wheel spin. Other times I have accelerated aggressively and it didn't come on, and probably shouldn't have so there definitely is a difference with how it's functioning.

 

Here is my TCS issue,

When making a 90 degree right hand turn, which is slightly down hill, in 4th gear, below 2000 rpm, the TCS comes on after a few seconds and then stays on for one tenth of a mile?

Note - the rear wheels are not leaving the ground, going the same speed in any other gear (1,2,3,5,6) through the same turn does not cause the TCS to come on.

Can reproduce at will, as long as the turn is 90 degrees, and down hill, even slightly. The dealer was able to reproduce, but not fix the issue.

 

Funny. It happened for me the other night in a 90 degree, slightly uphill right hander but I had just downshifted to 2nd ...I would say approximately 3K RPMs. I'm trying to document as much as I can about each instance to see if it helps point to something.

 

as soon as you turn on the car... roll the car back 20 feet and then forward 20 feet...

re-calibrate your tires...

 

OK...now you have my attention. As a relatively new visitor to this site, I have seen many of your posts and you seem to know what you're talking about. Can you provide any explanation to your suggestion of rolling back and forth 20 feet to recalibrate the tires. By the way, they are not stock. I have 20" Axis wheels with Pirelli PZeroes...255/35/ZR20 in front and 285/30/ZR20 in the rear.

 

Do different tire and wheel sizes mess up the tcs?

 

I read somewhere in another thread that the same tire and wheel size can. The front and rear should be different.

 

different tire sizes will effect TCS...

I need to pull out my Z Manual, but it talks about tire calibration in it...

im going to go look and see if I have one up front now...

 

Mine comes on all the time too. Probably 5-6 times a day. This is in L.A. traffic as well. However in each case, its either while making a 90 degree turn, or while changing gears (up or down). Many times I go "what the hell" because it feels like someone took away 200 horse for about 5 seconds. After a short (seems like forever) wait, everything is ok again. With it off, car is fine. I think they just way overdid the TCS limits. I'll probably thank them when we get some rain finally.

 

this is the issue.. the front tire has a larger diameter than the rear.. in stock form the rear tire has a larger diameter..

basically with your tires you are baking in certain amount of wheel spin (from the ecu's perspective).. the only way to solve is to get tires closer to the stock tire diameter stagger.. or just turn off TCS..

 

you need 285/35 in the rear...

rear needs to be a larger diamater by about 3/4"... wheel and tire shops will get you same diaimater front and rear which that tire size is above...

 

Last winter I ran winter rated 235/50 R17 on all corners. I had very little trouble with the TCS. When the TCS intervened the intervention seemed appropriate for the conditions.

 

Fat fingered, 225/50 NOT 235/50.

 

Great info...thanks. I think you might have broken the code. I have always been of the understanding that the middle number in the tire size (30 and 35 in my case) represented the sidewall height but that it was a percentage or ratio as compared to the tire width (255 and 285 in my case). Since the width of the front tire is narrower than the rear, I would have expected the the sidewall height number to be larger than the rear with the wider tire. So I thought it was ok to have a 35 on the front and a 30 on the rear. If what you say is accurate, then I think this is my problem. Guess I'll drive with TCS off until I need new sneakers for the car.

 

My only problem with TCS is it defaults to ON upon start up. With my wheel/tire setup (same 275/40/18 front and rear for street/track) I can't go 2 blocks and turn before it engages. I always turn TCS off while the car is warming up.

 

you can get a unit that will remembers the TCS off position so that you don't have to press the button every time you start the car. Have this and works like a charm

http://www.kptechnologies.net/

and when you get new tires use this website to check the diameter stagger versus the stock setup

http://www.miata.net/garage/tirecalc.html