TCS light comes on . Why?

[nsxtasy]

I did a quick check and your diameter ratio is 5.8%, which is larger than the 4.7% max your 1995 TCS is looking for.

You're misconstruing the ratios. The stock tire sizes on a '95 are 215/45-16 front and 245/40-17 rear, which are 4.7 percent larger in outer diameter than the front. That is NOT a maximum; that is the actual difference in tire sizes. The car has a tolerance of plus or minus 5 percent from that - in other words, the rears can be anywhere from 0.3 percent smaller to 9.7 percent larger - but that is theoretical, and there are other variables involved, so it's not an exact number. (For an example of one such variable, tread wear between a new tire and one that needs replacing is about a 2 percent difference in outer diameter. For another, tires are not always exactly the size they are labeled.)

On a '95, using tire sizes of 215/35-18 and 265/30-19, whose outer diameter is 5.6% larger than the front and less than 1 percent difference from the stock ratio of 4.7%, will NOT set off the TCS. Look elsewhere for your TCS problem.

 

[Old Guy]

The light on the cluster is on alway, never goes off or blinks. I saw in another thread that my CEL and TCS light might be related to an O2 sensor issue. I have custom basic test pipes on my 95 so that may be the issue. I installed them over 10 years ago so I’m assuming that I removed the two that were connected to the cats. So I’m guessing I just have to buy two new ones for the two that are remaining and add defoulers to Them? I’m probably going to get some Pride test pipes since mine are ugly.

That is a TCS error code problem, not a tire size problem.

If you removed the downstream O2 sensors on your 1995 (should be OBDII ???) you will have a perpetual CEL. There were some ECU CELs that could result in the TCS generating some error codes. As I recall O2 error codes was not one of them. There is a serial data line between the ECU and TCS and problems with that data line can cause mutual errors.

You can use a code reader to confirm exactly what codes are causing the CEL. Obviously O2 codes should pop up if you have removed O2 sensors. Find out if there is anything else. In order to read the TCS codes you will need to use the service check connector to trigger code display which will occur on the TCS light. Get ready to count the blinks. The CEL will also start blinking at the same time; but, those are ECU error codes not TCS error codes.

 

[19995NsxT]

That is a TCS error code problem, not a tire size problem.

If you removed the downstream O2 sensors on your 1995 (should be OBDII ???) you will have a perpetual CEL. There were some ECU CELs that could result in the TCS generating some error codes. As I recall O2 error codes was not one of them. There is a serial data line between the ECU and TCS and problems with that data line can cause mutual errors.

You can use a code reader to confirm exactly what codes are causing the CEL. Obviously O2 codes should pop up if you have removed O2 sensors. Find out if there is anything else. In order to read the TCS codes you will need to use the service check connector to trigger code display which will occur on the TCS light. Get ready to count the blinks. The CEL will also start blinking at the same time; but, those are ECU error codes not TCS error codes.

Ok I’ll try that and report back. Thanks for your help!

 

[Honcho]

You're misconstruing the ratios. The stock tire sizes on a '95 are 215/45-16 front and 245/40-17 rear, which are 4.7 percent larger in outer diameter than the front. That is NOT a maximum; that is the actual difference in tire sizes. The car has a tolerance of plus or minus 5 percent from that - in other words, the rears can be anywhere from 0.3 percent smaller to 9.7 percent larger - but that is theoretical, and there are other variables involved, so it's not an exact number. (For an example of one such variable, tread wear between a new tire and one that needs replacing is about a 2 percent difference in outer diameter. For another, tires are not always exactly the size they are labeled.)

On a '95, using tire sizes of 215/35-18 and 265/30-19, whose outer diameter is 5.6% larger than the front and less than 1 percent difference from the stock ratio of 4.7%, will NOT set off the TCS. Look elsewhere for your TCS problem.

Ken! You're still here!

 

[docjohn]

He came out from the shadows to spank you!!!!! :biggrin:

 

[Honcho]

he came out from the shadows to spank you!!!!! :biggrin:

lol