tcs acting up

[sheldement]

i think i have a faulty sensor or something. I can be driving my 91 in normal dry conditions, just cruising in a straight line, and start to mildly accelerate when my tcs operation light begins to blink and my accelerator pedal gets hard. i can downshift and accelerate fine, but it seems to happen most when my rpms are below 2500. ???

the repair manual i have didn't give me much help. it didn't even mention the operation light, just the warning light. however, my warning light does not flash, just the operation light.

i can turn the tcs off and the car will accelerate fine. i just had new tires put on the front, but they are stock size on stock wheels.

anyway, any advice is appreciated. Thanks!

 

[nsxtasy]

What size are your tires?

The most common cause of TCS activation is tire sizes that change the ratio of the front and rear outer diameters too much from stock. Sometimes it doesn't show up when the tires are new, but then shows up as the tires wear at different rates (front vs rear).

 

[sheldement]

the front are 215/45/16. They are the ones i just had put on. they are the same size as the old ones. The rear tires i can't remember at the moment (i'm not at home), but they were replaced last year with the size stated in the users manual. They are stock wheels.

 

[nsxtasy]

the front are 215/45/16. They are the ones i just had put on. they are the same size as the old ones. The rear tires i can't remember at the moment (i'm not at home), but they were replaced last year with the size stated in the users manual. They are stock wheels.

Well the stock wheel and tire sizes for your car are 15" front with 205/50-15 tires, and 16" rear with 225/50-16 tires. The '94-01 cars came with 16" fronts with 215/45-16 tires, and 17" rear with 245/40-17 tires. It's not clear from your description whether you are using 16" rears or 17" rears. But if you have brand new front tires in 215/45-16, and your rear tires are rather worn - either 225/50-16 or 245/40-17 - then it's quite possible that this is causing the TCS to activate. The 215/45-16 size is 2.4 percent larger in diameter than your stock front size, the 245/40-17 is 0.6 percent smaller than your stock rear size, and if your rear tires are worn, that can make them up to 2 percent smaller in diameter as well. All that adds up to 5 percent which is enough to cause the TCS to activate. So that is the likely cause.

You can live with it, or you can replace your rear tires. That alone should be enough for your TCS to stop lighting up. Since you're using the 215/45-16 front tires, you might consider going with 255/40-17 rear tires, which are 0.7 percent larger than stock; the slightly larger diameter will probably be enough to prevent the TCS from activating even after they wear down.

 

[sheldement]

my bad. the wheels are stock wheels off a 2001. the previous owner put them on about 6 years ago. so i'm running staggered 16/17. would tha sill be the issue after all these years?

 

[docjohn]

we still need your rear tire size,having stock wheels means little,the prior owner might have non oem sized tires.

 

[sheldement]

sorry guys, i should have had this info earlier. the rear tires are 245/40/17. they were just put on last summer and have most of the tread still on them.

 

[nsxtasy]

Different tires labeled as the same size can actually have a certain amount of variation in size.

I haven't had any problems using the OEM 215/45-16 and 245/40-17 tires on my '91, but it's still a possibility. The fact that this started after you put on new front tires is an indication that TCS may be working properly, and it's the tire size that's probably causing the TCS to activate.

Do you still have your stock wheels and tires? Or do you have a friend with an extra set of stock NSX wheels and tires? If so, you could swap those on and see if the TCS problem goes away. Or if you have a friend with slightly larger diameter NSX rear tires (like 255/40-17, 255/35-18, 265/35-18, or 275/30-19), maybe he'd be willing to swap rear tires with yours temporarily for a test drive to see if the TCS problem goes away.

 

[sheldement]

well, im the only nsx within several hours. i know there are more here in mo, but i don't know any them. unfortunately i don't have any other tires or wheels, either. i guess i can post another thread to see if anyone near here would want to meet up. st.louis is only an hour and a half from here.