doanlaw

Ok, after 3.5K miles on the new rig and the first stock dino to mobile 1 oil change, i finally got around to checking the pressure on the 265/70/17 revo's i put on at 500 miles and unsurprisingly discount tires put em up to 40 PSI. No wonder i've been blowin off dawn patrol sessions because of a sore back.... Based on my knowldedge of taller tires, wheel size, GVWR, etc, (i'm running the stocker 17x7.5) i air'd down to 28 front, 24 rear and saved the remaining life of my tires and my c5 in my spinal column...so ofcourse my low tire pressure warning light fires up...so i air'd back up to 30 front, 28 rear and it still remains on...what gives??? hopefully toyota didn't incorporate any governor control side effect thingy on this one...

Victor

I don't know anything about the tire pressure sensor but....it would be L5 in your spine (lumbar). If you have a C5 in your lower back get to a doctor quick!

Seriously, how does that system work and what did it cost. I'm assuming it is some sort of low pressure warning system when your tire pressure drops below a set point. I personally like a firm ride so I keep my tires at 39 PSI front and 42 PSI rear. When I want a softer ride a go to 38 and 40. I notice a big change in the steering effort below 38 PSI.

Ghost Rider

Did you changed the pressure in the spare?? That could trip it, also...

My99

I base my tire pressures on tie wear. If they're wearing in the middle, I air up. If they're wearing on the sides, I air down. My style of driving keeps my tire pressures about +3 to +5 above manufacture specs in order to get the best life out of the tires. I can never feel a difference in the ride, you guys have some sensitive rears Keep in mind, the new tires will VERY likely have a much stiffer sidewall than what the truck came with OEM.

BTW, tell me more about this monitoring system for the air pressure. How's it work. I know the corvette's have had it for a few years, I never knew how that worked either. Of course without a spare they really need it.

bulldog-yota

I have the same tires and run at 34 front and back and ride is pretty good. Maybe go up to 32 front and rear and see what it does. Also as stated check the spare is at 32 or more.

Then go down to 30 front and back and see if the light still comes on. My 03 doesn't have that feature, but I think the 28 in the back is too low for it, maybe 30 is the threshold for the sensor to come on.

Good Times

I thought the system checked for the diff in pressure in all the vehicles? So if all the tires were at 28 it's okay. But if a few were at 30 and the others at 24 it'll flag it as being deflated?

Dunno but you might want to just do a test run at 30psi or something where all 4 tires are the same and then check. I don't think the spare is connected but you might want to check there too just incase.

PistonSlap

Are you checking them when they are cold? That is when you need to check your pressure because it will increase about 4-5 psi when your tires get hot.

Sabony

The system does two things actually, it checks to see if one tire is a fair amount less (including the spair which might be your issue) just like Goodtimes said, but it also has a set number that it uses to check against.

I don't know exactly how these two systems work together and they seem to work against each other, but this is how a dealer tech explained it to me and I was too confused to know how to ask for clarification.

I had a problem on mine coming from the factory that had the sensors set at the wrong base value which caused it to go off for no reason. They just had to reset the sensors to get it fixed. This is their story at least. It could have been that they had the just pumped the tires up too much without adjusting the spare accordingly...I don't know for sure. It is hard to trust a place that claims that to check the car before giving it to me and the first thing I see getting in is a light on the dash. Do you think they checked it out?

doanlaw

[QUOTE=Sabony]The system does two things actually, it checks to see if one tire is a fair amount less (including the spair which might be your issue) just like Goodtimes said, but it also has a set number that it uses to check against.

I don't know exactly how these two systems work together and they seem to work against each other...QUOTE]

Hmmm, I didn't check my spare, but since I had it replaced with the others too, it's probably at 40psi too. I'll deflate 10 psi and see what happens.