Sunger

I recently changed my stock wheels to 04 track model 18" rays. After I drove for about 20 miles, all of sudden TPMS light came on. So I stopped at the gas station and checked the tire pressure. On the tires, it said the pressure need to be at 44psi so I added air to 44psi, but the light still stays on. I bought the rims from a local private seller and he told me that the tires on them weren't stock. These tires are BFG g-force KDW. 245 on the fronts and 275 on the rear. So....I'm wondering if these rims even have TPMS sensors? Or it's because of oversize of tires? Please help!!

PDX_Racer

iTrader: (2)

If the valve stems don't have metal stems, then there's no TPMS.

However, even if they are there, you need to program the car to recognize *those* TPMSs -- it's not automatic.

DavesZ#3

iTrader: (26)

Maybe this explanation will make sense....

https://my350z.com/forum/showthread....9&postcount=44

Sunger

thanks for the info guys oh and one more thing...isn't my digital gauge supposed to flash or say somethin about tire pressure? I checked my digital gauge and it's not reading anything...

crg914

iTrader: (5)

FYI, you don't set the pressure to the max pressure on the tire. You set it to what the car needs as designated by the sticker on the door jamb.

TPM sensors will set the light off if the pressure is too high as well as too low.

halcyon901

iTrader: (2)

the reason your digital gauge is not "flashing" anything is because you did not re-program the new TPMS for your car

sorry if this might confuse you, but you could take the TPMS from your stock wheels and put them on the new wheels. that way, you dont have to go to the stealership to have them reprogram the new ones (just make sure to put the correct ones on the correct tires, old front right to new front right, etc...)....

and +1 for what crg914 says, dont over-inflate the tires, go by what the manual says.

Sunger

so you're saying I should still follow whatever it says on the doorjam/manual even though these tires aren't stock? Again, these tires are bigger than stock... oh haha and one more and this will be the last question lol sorry...I'm another Z noob...Ummm would this whole TPMS problem will affect anything to the car? like performance-wise or electronic-wise... I'm pretty sure my tire pressure is fine, but the tpms wouldn't jus reqonize the new wheels. It wouldn't really bother me having that (!) light on as long as it wouldn't affect anything...

crg914

iTrader: (5)

The pressure on the tire is the max pressure at which that tire can safely be used. Tire pressure effects ride quality, spring rate, handling etc. And has been set for the car by the manufacturer. Always set the tire pressure to the recommended pressure in the manual or on the placard on the driver's door jamb, regardless of type or size of tire.

Sunger

I see...So I'll go ahead and take some air out and see what happens. Thanks guys

DavesZ#3

iTrader: (26)

As explained in the link I provided, if you have a 2007 or later Z, then the actual pressure doesn't display in the multi-function gauge. All you'll get is a low pressure warning.

DavesZ#3

iTrader: (26)

O-really? How high does it have to go to set it off? I've run mine over 45psi and never received a warning of any kind. There's nothing in the FSM that make reference to "over pressure" and TPMS.

crg914

iTrader: (5)

Well, that's kind of an assumption on my part. I work for Ford and know that on a Ford vehicle the TPMS will illuminate if the pressure is too for below or above the recommended pressure.

When I worked at an independent shop I had the same experience with a few GMs. I would just assume Nissan would employ a similar strategy. I have a buddy who works at the Nissan dealership nearby, I can verify if you'd like a more finite answer.

DavesZ#3

iTrader: (26)

The Nissan system is made by Schrader, not sure if they make the one for Ford or GM.

The system triggers low at about 28 PSI which is 25% below the normal 35psi. I've run as high as 45 PSI which is 29% over the normal and never triggered a response.

The reason TPMS is mandatory on vehicles now is because underinflated tires are the #1 cause of premature tire failures. Not really much harm in having them overinflated other than harsh ride and uneven wear. Maybe Ford and GM owners have problems with overinflating them too.

crg914

iTrader: (5)

Overinflation is dangerous as well. It makes the tire more vulnerable to damage caused by potholes and curbs, less stability from a smaller footprint as well as more wear on the suspension components from a harsher ride.

That's why Ford has a min and max limit. Perhaps Nissan isn't as safety conscious.