Did a search and looked through the manual...

My low pressure warning light is lit. Checked pressure in all tires and all is well. What do I need to do to get it to go out?

If you have enough air in each tire then it will go out on it's own after a few miles...
If it does not go out then take it to the dealership...

It turns on at 28psi and rumor has it that if any one tire is not equal to the pressure of the rest the light will go on. There are a few threads on this that explain it in detail and one posted sections out of the manual about it.

All tires had 35PSI in them minimum. It came on after the first cold night and has been on ever since. I pushed the pressure up on all to 37 or so, but it's still lit. Time for a trip to the dealer I suppose... I'd rather have no system at all then have a flaky one that I can't trust.

Are you checking the tires when cold or hot?

Also, it does take a few miles before it turns off.

Actually, the system probably detects flats by comparing rotation of the wheels detected by the ABS.. not by sensing pressure. The dealer might be able to reset it.. otherwise, you might have to take a *long* drive for the system to realize it's ok (I think my Scion manual said it took 40 minutes of travel before its system got a good baseline -- but.. at least it had a reset button!)

My roommate's Corolla has had the flat warning light since three weeks after he bought it (the reset button didn't work for him), and the dealer has looked at it twice, So.. GOOD LUCK!

-K

Edit: Just looked it up for myself.. it's really weird that the manual lists such a specific low pressure reading (28psi) that would activate the system, when the system has no sensors to detect the actual pressure! --Very misleading-- The original Hummer was the only vehicle, to my knowledge, that could actually detect (I think it could also adjust) the pressure in the tires. That would be killer.

The 05-06 X has sensors in the wheels that detect pressure. They are mounted to the back side of the valve stem.

The Hummer also has sensors, and yes atleast the H1 could inflate and deflate the tires from inside the truck. I don't know if the H2 and H3 have the same system.

Do a search of this forum for "tire light" there are atleast two threads that have a lot of good information.

Hmm.. just because someone you read it somewhere doesn't mean it's good information. I call BS.

Okay, assuming there IS a sensor on the back of the valve stem, how does information get back to the computer? It ain't wireless!

You'd either have to have special rims for the system to work, or you'd have to diconnect some wires every time you change your wheels - and what would the wires look like after how many revolutions? You'd have to use brushes like in an electric motor to get the electrical signal past the fact that your wheels are rotating so much. Also, if the system compared actual pressures, it wouldn't take 'a few miles' to turn off.. it'd know immediately, don't you think? C'mon, think a little more critically about it, and it makes sense that this calculation is done based on rotation of the wheels.

-K

Actually, it IS wireless. Read the flyer, and see who they manufacture these for...

Brochure

The H1 could inflate/deflate. The H2 & H3 have "similar" looking hubs, but the don't have this feature.



Poser.

Wow.. those are in our truck? I stand corrected! Sorry guys!

-K

Don't call BS until you have read the Owners Manual or the Service Manual, or even 10 different threads talking about them

That was what I assumed, but you know what happens when you assume don't ya?

I think it is a cool idea, but is it really needed? I would settle for someone just giving me a decent place to mount a compressor and maybe even a small tank on the X.

Yeah, yeah.. I seriously had no idea that the tech was there for this -- or that it would be affordable/practical for use in an average car.

I'm kinda mad that there isn't more up front information in the manual/from the dealer.. All it talks about is 'the system' -- I mean.. given the right scenario, people might be getting rid of their wheels, and unknowingly losing those pressure monitors! I'd be super pissed about that.

Anyway, thanks for being nice as dead wrong and rude as I was!

-K

Some place in the Owners Manual it talks about why if you change to the spare tire the low pressure light comes on. This is because the spare does not have the sensor. So it's there, just not as clear as the big bold letters on the cover of the Hitchhikers Guide to the Galaxy.

That's a good question...but it is mandated. The NHTSA has mandated a phase in of Tire Pressure Monitor Systems (TPMS) on all vehicles by September 1, 2007. There is a lot of push back by industry, but I think it is going forward. Here is a link with the details:

49 CFR Parts 571 and 585

regards,

No, I was talking about the ability to inflate and deflate the tires from inside the truck, like in an H1. Not the tire monitor system.

On the H1 it is needed. When in the thick of battle, it would sure be nice to air down the tires when getting off the pavement, and someone it taking shots at you!

On your X, you can get yer lazy butt out, take your sweet time, and air down manually. There's even some nifty replacement valves that will air down your tires quickly: Linky.

If you buy an aftermarket rear bumper, with spare tire holder, that will free up room under your X to mount a 2 gallon airtank, and chassis mounted air compressor.

not so sure that is true. i had to put my spare on and the tire pressure light did not come on. (actually, it did after about an hour of hwy driving, stayed on for 20min and then went off until the dealer fixed the flat tire. probably went on due to difference in tire pressure) my guess is that there is a sensor on the full spare. not sure of the spares on the s models though...

I just went and checked (in my new, enlightened state of mind ) and my spare has a normal, rubber stem.. this is not consistent with the other four wheels, and the Schrader Electronics model sensor that was listed earlier in this thread. I'm guessing the car was picking up a signal from the flat.. but hey -- I've been wrong before!

-K

Owners Manual (Section 8-30)

TIRE PRESSURE
Low tire pressure warning system (if
so equipped)
This vehicle is equipped with the low tire pressure
warning system. It monitors tire pressure of
all tires except the spare. When the tire pressure
monitoring system warning light is lit, one or more
of your tires is significantly underinflated.
The low tire pressure warning system will activate
only when the vehicle is driven at speeds above
20 MPH (32 km/h). Also, this system may not
detect a sudden drop in tire pressure (for example
a flat tire while driving).
For more details, refer to “Low tire pressure warning
light” in the “Instruments and controls” section,
”Tire pressure information” in the “Display
screen, heater, air conditioner and audio systems
” section, “Low tire pressure warning system
” in the “Starting and driving” section, and
“Flat tire” in the “In case of emergency” section.

what I'd like to know is when I decide to replace my OEM tires (soon), is that guy in the tire shop going to mangle my flat tire sensors with his machine while replacing my tires?...

They shouldn't but if they do, it's on them to replace what they break.

in response to some of the replies stating that they thought it was the type of system that compares wheel revolutions for readings. that is not the case with the nissan sensors. the sensors are actually pressure sensor units on the valve stem, not the cheaper tire system like the ABS one mentioned. I had the dealer confirm this with a manual and a dealer hand out. the bad thing about the ABS versions aside from just cutting cost corners for manufacturers is that in a long corner the wheels rotate at different speeds. thus the one side of tires may seem smaller since the inner side makes more revolutions. thus the computer thinks flats are in the works and flags it. and thus pissing owners off and making them rather not have it in the first place. hope that helps people.

well i gotta remark, i never found that button on all the humvees and uparmoreds i drove...of course we managed to get them stuck every other time we went out, so we probably had alot of stuff we didn't know about..

Well, maybe yours didn't have it. I was under the impression all Humvees had it, but it turns out that not all do...

This unique configuration of components along with military 37x12.5 radial tires with low-profile runflat devices allows the HMMWV to go places that no other wheeled vehicle in U.S. or foreign military service could go. Some HMMWVs are equipped with an optional central tire inflation system (CTIS). This enables the operator to adjust tire pressure from the driver's seat "on the move," to adapt to changing terrain conditions for greater off-road mobility.

The full story is at this link.

im in the army and i can tell you 99 percent of the m998s or its variants ("humvee") in the military do not have CTIS. its an option for civilians to baost about. the main vehicles in inventory with CTIS would be your larger vehicles like LMTVs and upgraded duece-n-a halfs and five-tons.

Alright im being a skeptic here, I just had the light come on for me. I know damn well i dont have those sensor thingies in my wheels, I bought 767 steelies... Im inclined to think it uses abs like karlan says. One of my muds was a little low, 27 and the rest are about 35... i just filled it so we will see how long it takes for the light to go out.

Damn, must keep you busy driving all of 'em.

Do you have an 05/06? Where did you get steel wheels to fit? The 05/06 uses sensors, I think we have already proved that.

Just a side note - my pressure sensor clicked on about a week ago. At the time I didn't have a pressure gauge in my Xterra (and for some reason, no place in NYC seems to seel them), so I stopped by a gas station and added a bit more air to each tire. The sensor didn't go off. When I final was able to get to an Autozone a week later to get a gauge - I found the front passenger tire at 80psi, and others at 60psi. (explains the bouncy, unstable ride I've been having lately).

Bottom line is that the sensor also seems to go off when you have too much pressure in the tires or there is a very unequal distribution of pressure between tires. It was odd, because I hadn't added any air since rolling off the dealer lot, but I guess temperature changes could have come into play.

60 or 80 psi are you sure?
I am certain that temperature did not play a roll in going from 35 psi to 60 or 80 psi.

Mine came on yesterday. All four tires (at 900 miles on the odometer) had 28-30 psi. I pumped them all up to 35 and the light went out in a quarter mile of driving.

The sensors will come on if one tire is a lot different than the others or if any one tire is below 28psi.

That would explain why at 80 and 60 psi the sensor went off.

How new if your X? I found when I got mine home from the dealer that the tires had about 55 psi in them. I let out a lot of air.

My light came on today on the way home from work. The left side tires had 32 p.s.i., right side had 33 p.s.i. I put 35 in all four, we'll see if the light goes off tomorrow!

I think the 60 to 80 psi came from my inflating the tires when I thought the light was on because the pressure was low. Once I got a gague and could accurately set the pressure to 35psi, the light went off. My X has 10,000 miles on it now, had it since March.

You have had the X since March, you put 10,000 miles on it and this was the first time you checked the pressure? Wow, hope your tires last.

Yeah, my bad assuming the dealer would actually check everything before I left the lot. I'm looking to put some BFGs on anyway, so I'm not overly concerned about the longevity of the stock tires.

Well, even if they were set at the dealer (which they never are), after 10K miles and 7 months, they should have been checked.

I check my tire pressure and oil every other fill-up which is about 2 weeks and/or 600 miles.

Yep, I was planning on rotating the tires and checking the pressure in each this weekend. Unfortunately, the pressure sensor kicked on a few weeks beforehand.

I was just sharing some first-hand experience showing that the pressure sensors are not only tripped when pressure is low...not looking for a lecture on my maintenance procedures.

Some place in the Owners Manual it talks about why if you change to the spare tire the low pressure light comes on. This is because the spare does not have the sensor. So it's there, just not as clear as the big bold letters on the cover of the Hitchhikers Guide to the Galaxy.

Hope this isn't true. Just rotated my tires and included the full-size spare, thinking it was smart and would stretch tire life. It doesn't make much sense to include a full-sized aluminum wheeled spare, and not include the sensor!

Pull out the owners manual. It's in there.

EDIT:

2005 Owners Manual
Section 6-2
LOW TIRE PRESSURE WARNING
SYSTEM
This vehicle is equipped with the low tire pressure
warning system. It monitors tire pressure of
all tires except the spare. When the tire pressure
monitoring system warning light is lit, one or more
of your tires is significantly under-inflated. If
equipped, the system also displays pressure of
all tires (except the spare tire) on the display
screen by sending a signal from a sensor that is
installed in each wheel. If the vehicle is being
driven with low tire pressure (lower than 28 psi,
193 kPa), the low tire pressure warning system
will activate and warn you of it by the low tire
pressure warning light. This system will activate
only when the vehicle is driven at speeds above
20 MPH (32 km/h). For more details, refer to
“Warning/indicator lights and audible reminders”
in the “Instruments and controls” section, “Tire
pressure information” in the “Display screen,
heater, air conditioner and audio systems” section
and “Low tire pressure warning system” in
the “Starting and driving” section.

Hmmm....I am willing to bet that the "SPARE" is the one not hooked to a hub, regardless of which of the five rims you have....

IE: Only the hubs connect the tire to the system, so the spare isn't on a hub...and isn't monitored. (When you rotate, the tire that goes from a hub to the spare position becomes the next unmonitored tire, etc...)



Easy way to tell, look at your spare next to one of the known working rims...the rims have a channel for this purpose...., the spare rim and the normally mounted rim should both have this feature.

Example of the other way: My wife's Mini Cooper has a little airline connection you screw onto the spare tire's valve stem before storage...the car monitors the spare's pressure via that connection.

I thought it was determined earlier that the system was wireless, using an RF signal?

The way you can tell, and someone said he already looked, is to see if the spare has a metal (aluminum) valve stem. If it's rubber there isn't a sensor on the other side of it.

This thread should be renamed a tad and stickyed.

Okay, my tire sensor alarm just went off this morning. Damn that's loud.

One tire was just 4-5psi below the others. 34,34,33,29.

I don't think it has a screw or any thing, but I did go off road yesterday for about 5 hours. I'll look at it at lunch.

After checking the tires and driving to work, I debated whether or not I like this new sensor. I decided it's okay. With out it, I might have driven on that tire (with or without screw in it) for a week before I would have checked it. With the sensor, I'm told I have a tire issue, I need to check out.

With that said 5 psi might be to small of a difference. Maybe 8 psi would work a lil better.

It's more likely not the change in the pressure between the tires, but that one was at 29psi. That is close enough to 28 psi that it probably tripped the sensor.

Also keep in mind that your gauge is likely off some. It might really be 28 PSI or lower.

How many times have you cruised down the road and noticed someone driving on a half flat tire? All too common a sight for me. I think this is good item, and I'm glad to have it onboard. Then again, mine hasn't gone off.

I too like the system, I check my pressure every 2 weeks or so and just this last Friday the light came on. After checked both my front tires were down around the 28psi mark. I blame this on the 15ºF temps that night.

I do wish it was hooked to an LCD display and actually tell you the pressure. From what I have read, the system has this ability.

Note to Nissan: see above. hehe, yep a dash display would kick ass. Use existing lcd display, and push button. Mark it: LF:34 RF:34 LR:33 RL:28

Just wait, that WILL be a feature on the '07+ Pathfinder.

But I don't own an 07 Pathfinder, I own an 05 X and I want it!

Okay, what's the trick/hint for resetting the sensor again?

When the pressure sensor is triggered because the air pressure is too low you have to put some air into it to reset it. I have found that setting the pressure to 35 psi seems to work.

Then when you drive your X the next time and go over 20 mph the warning light should go off.

I did that I'll recheck all and try again.

The same tire is back down to 28! I checked for screws no screws or nails.

Stem not leaking...checked with spit. Did I break the tire bead or a pinch flat?

Did you also check the valve itself? I would use a soap and water mixture.

Well, I spoke too soon. Yesterday was our first cool morning here in FL. I backed out, and my alarm sounded. All the tires looked fine, so I drove it to work.

At lunchtime, I checked and found one to be a little low. Filled all of them to ~35 PSI, but the light didn't go out even after shutting off the key. But once I rolled out of the gas station, it finally did go out. Cool again this morning, no warning light.

The system works.

I have dealt with this alarm too. lol just put in 35 psi and started driving. Finally the light went out after bout 10 minutes of driving.

A question about these sensors...
Would it ruin anything if you used a can of 'flat fix' if you ever got a puncture? I'm wondering if the gunk they put in the flat tire fix cans would harm the sensor mechanics in any way?

That's a good question sarmike. I once tried to get a nail taken out of a tire that I used the fix a flat stuff on and the tire guy wouldn't touch it. I had to buy a new tire.

I know there is a warning on the cans that the 'propellant' is flammable. That might be why some tire places won't touch them. I also just found the sensor answer:
"FLAT repair: using a can of pressurized tire repair sealant will clog the sensor and it will have to be replaced."
Tire Pressure Sensor Unit - 2003 to 2005 Xterra
Code: 40700-Z33
Price:$92.88

Ouch! Gonna take that can right out of my car asap!

Had a flat a couple of weeks ago and replaced it with the spare and I didn't see/hear any warning about having low pressure while I ran on the spare. I ended up just replacing all 5 tires rather than fixing the flat. I checked the manual and it mentioned something about having to reset the pressure monitor. I guess I will have the dealer check the pressure monitor when I get my hitch replacement to see if it's working.

My issue was a small puncture. I had a patch put on, it's back to normal.

fix-a-flat: The manual says do NOT use canned fixaflats. The gunk will harm the sensors.

do-it-yourself plugs, and tire store patches are a-okay.

One more believer here:
I was following this post because MY pressure light went on as well. Tried checking the air at the gas station ~ all seemed fine. Added air to one tire that 'looked' low, but light remained on. Last night, went to store & bought 'reliable' air guage and tires read: 30, 31,31,32. Brought them all up to 35 by the new guage ~ presto. W/in .4 miles of driving after refill, pressure light goes out.

I have had the same thing happen to me. I live here in Brownsville, Texas and most of the time the temp stays above 70 F. With a cool front the night temps dip down to the upper 40's and low 50's. The sensor came on this morning while it was 52 F. I drove to work and parked it. It stayed lit all the way to work..about 20 miles. At lunch I went out to the truck and when it started the light never came on. The air temp was over 75 F at that point. When I left to go home around 6:15 the light was back on again...and again it stayed lit all the way home again...the air temp had dropped with the sunset. I looked at all four tires and they looked fine. I checked the pressure right now and I got 30, 31, 32 and 30 neither one a significant difference from each other considering that I am using a fairly accurate dial gauge. Even still it has a +/- 1 psi error.

The point I feel that needs to be made is that it is useless to have a sensor which activates at 28 psi. When they say "significant" air pressure drop they should consider the potential of temperature related pressure drops or rises. The low setting should be around 20 psi. Otherwise the sensor will just be the proverbial boy crying wolf and will get ignored...which is the opposite effect of providing the sensor in the first place.

Yeah 28 is to high. 25, would be a tad bit better.

The pressure sensor is not there for the convenience of the consumer. It is there to help the automaker from getting sued. Most people don't bother to check their tires and want someone to blame when a tire gets low, overheats and blows out while the driver is speeding. :p

I agree. I also suspect that the low pressure sensor info is probably stored so in the event of an accident Nissan will be able to say your tires were underinflated and it was your fault not theirs.

That thing is annoying when it goes off though. The first time mine went off was at my dad's house. It was nice the day before and got really cold over night. I didn't bother to stop to get air in the tires since I was driving down to Potts to go wheelin any how. Right after I was done wheelin I stopped to get gas and aired up to about 35 psi hot. The light has been off ever since.

I thought by 2007 all autos have to have it. Congress passed that a year ago.

Well, here is a curve for you. I'll probably end up going to the dealer. Well that is going to take them a while. Unless you guys have some good info. Temperature dropped to below 0 F last night. Started the X and started driving. about 1/4 mile down the road, Low Pressure light comes on with an annoying/loud sound. All tires are within specs on the pressure. Could it be that this is a very flaky system (like few other things on this truck), and that it is starting to fail so soon. I got 12000mi on the truck. The light is still on. And please, no stupid comments. There is 5 pages on this topic already and after the first 3, I stopped. Some people don't have time sitting around and reading everything. Thanks for the feedback.

I have not seen a problem with mine, and seeing as the system is not a Nissan system, and is used in other vehicles I doubt the system is "flaky".

It's been getting cold around here (single digits at night) and the only time I had a problem was the first night it reached the teens.

When you say the tire pressure is within specs;
Do you have a decent tire gauge?
what is the tire pressure?
Are you checking the pressure cold?
Are they all above 28psi (cold)?
Are all tires within a couple PSI of each other?
Have you put the spare on or had the spare rotated in during a tire change?

Fill tires to 36psi tonight. Drive for less than a mile. Problem solved.

The 28psi sensor has a hair trigger.

It could have been a flaky guage that I was using. Although it was a digital gauge, that has not done bad by me since I got it. For the sake, I went and inflated all the tires at a gas station. Unfortunatelly without a gauge. Just counting the seconds so that at least I inflate them evenly, and check again once I get home. As soon as I started driving the light went off, and has not come back yet. I have to say that this is a very sensitive system than. Because, even if I was showing 34-35psi on the gauge, I doubt that it was actuall ~28psi. I'm a little confused on this one. I guess having this system is ok, but it is definatelly too sensitive. Thank you for the reply. I greatlly appreciate it.

My pressure warning light comes on at about 32 psi. I've tested them over and over, but at least one of my four sensors must have been calibrated wrong. At some point, I will have to get the dealer to fix this.

Wow...so much info and posts on this. I'm shocked!

So, my Low Tire Pressure warning came on one(1) day after I had it new from the dealership. I know that the system has to be synched up to the sensors during the PDI(Pre-Delivery Inspection) process. The only way to do this is by having the dealership technician plug into the OBD II port for the computer and synching/reseting the system. Something i'm having the dealership do next week. I agree, the warning alarm for it is truly obnoxious. I've checked my inflation every few days since I don't have much to do since the accident. All tires are remaining @ 32psi. I don't get too many hot/cold variances since I live in Southern California and we don't really have "weather" here.

I'd love to know how many people experienced this problem shortly after they got their XTerra brand new. I can't believe that the technicians flagg 3/10ths of an hour for 2 or 3 minutes worth of work to do this.

I love my new XTERRA! I've wanted one since they first came out in 2000. After my Ford Expedition got wrecked and was deemed a total loss, I went out and got myself what I've been craving for years. Now i've got it and couldn't be happier about the choice. Although in Southern California, it took some searching to find an Off-Road model in 4WD and a manual transmission...but I GOT IT!

Great site, will remain a life-long member if possible. Great tips and tricks too!

B.

You might want to pump your tires up to at least 35 psi to see if the alarm clears.

I have found mine will not clear at 32 psi.

Could save a visit to the stealer.

I got my 2005 two weeks ago on Thursday Dec 1st. Right after I pulled out of the dealership I went home and packed my stuff for my snowboard trip to Mammoth. So I was on my first road trip 2 hours after I drove off the dealer Anyway, so I get to about 30 miles before Mammoth and it was snowing, so I turned on my 4x4 and left it on all 4 days. About 30mins after the low tire presure light goes on. I checked the tires the next morning and they were fine. The light was on the 4 days I was there. It finally turned off about 40mins away from Mammoth, by this time I had it back on 4x2. Someone told me it was the below freezing temps and high altitude. I'm hoping that's true and not that something is wrong with my sensor. Does this make sense to you guys? I'm no car expert

The recommended psi is located on the inside door jam of the driver's side. Mine is 35 psi (05 SE). I would make certain that your tire pressure is at this level. My pressure sensor light came on, and my tires were actually low. Once filled to 35, and after a short drive, the light went out.

Yep, Cold temps make the pressure lower relative to the outside.

Make sure you are using a good quality tire guage. The sensor goes off at 28psi. If you are using a cheap gauge then there is a chance that the pressure is below 28psi and the gauge is showing 32.

But yes, temp plays a big part in tire pressure.

I had mine go off the other day here in Maryland when the temp dropped to about 15 degrees. Checked the tires and they were all showing about 28 pounds. I inflated them to 32 or 33 and drove like 3 feet and the light went off. The light had never come on before so I'm pretty sure it was the cold temps. They must have been sitting at 29 or 30 for the last couple months.

My God this whole pressure detection system seems to be more trouble than it is worth. Cold temps, one tire down a few pounds, alarms going off...it is ridiculous.

Find a way to disable the damn thing and just check the pressure every so often or when something feels really strange. When a single tire is down to about 15 psi you will feel a pull...it is not like the truck is going to flip on next curve.

The whole tire wear thing is "overblown" as well. A few pounds mismatch will not significantly reduce wear. If you check pressure pressure every few months this will not be a problem.

Plus, if you off-road (or play in deep snow), you will be constantly changing pressure.

I like many of the 05 enhancements, but the whole tire pressure thing is more for BMW's and mall crawlers, not the X.

re: cold temperatures and lower tire pressure...

I'm going from memory on this, but I think you lose 1 PSI for every 10 degrees the temperature drops.

I agree, anyone good with wiring schematics? I'd love to just bypass the whole system. Our 300M has the TPM system but that actually tells you what pressure is in what tire, even the spare. If the X is just going to tell you something may be off, who cares? Anyway, it would be nice to know if there were an easy way to disable this thing. Any takers?

Well, I have an 05, and let me tell you from experience, it works as advertised.

People that don't own one thinks the alarm keeps going off. Not so. It'll sound one time, then the idiot will stay on. It won't sound again until the system has been reset. No need to pull fuses, or rewire the X. The system works perfectly.

SUVs are top heavy, and more prone to rolling. With the added weight, they are also more likely to roll a tire off the bead. Lots of data online about this topic.

Mine went off once, I had a low tire. Later that day I shot 35 PSI in all of them. Problem solved, alarm reset, hasn't sounded again in a month.

If you haven't read the new regulations, here ya go:

In April 2005, NHTSA issued a rule requiring automakers to install systems in all new passenger cars and trucks by the 2008 model year, beginning a phase-in with 2006 model year vehicles.

All vehicles will have this soon...