Jeep Garage  - Jeep Forum

Jeep Garage - Jeep Forum (http://www.jeepgarage.org/forums.php)
-   Troubleshooting/Problems (http://www.jeepgarage.org/f203/)
-   -   Tire Air Pressure Sensors (http://www.jeepgarage.org/f203/tire-air-pressure-sensors-51494.html)

Me Fix 12-12-2012 01:46 PM

Tire Air Pressure Sensors
 
My 2004 Overland has the Rogue Wheels and the tire air pressure sensor system.

I park in a heated garage so the condition does not show up until after I have been out for awhile. It seems that after the Jeep sets outside awhile in the cold, which was 24 deg F this morning, I get a warning that a tire is low. The readout shows all tires at 25 PSI or 26 PSI. None of them look low or any different from each other and I remember checking all of them last month when I rotated the tires. The weather was warmer then and I try keeping all at 35 PSI. They seem to wear very good at 35 PSI.

I wonder if the cold effects the pressure? Maybe thats why I am getting the warning now. Or could it be the valve stem units have batteries which feel or sense the cold and send the readings back to the receiver which then displays the readings. I guess I just don't know how they work. Does anyone have any ideas. Maybe as it gets cold and the pressures are lower, they reach a point that kicks in a default warning which might come at 26 PSI even when all tires are at or about the same PSI. I baught this Jeep used and have not had to buy tires yet. I have heard that when a tire store changes tires on rims that have air pressure sensors they usually let the air out, lossen the valve stems by taking off the retaining nuts allowing the valve stems to fall into the tire area before they take the tire off the rim. This keeps them from damaging the valve stems with the tire removal equipment. After taking the stems loose they then have to sell you a new gaskets set for each valve stem so it will seal on the rim with the new tire. Old seals may fail causing you lots of problems!

Frango100 12-12-2012 03:13 PM

Re: Tire Air Pressure Sensors
 
This is the info i found in the service manual:

The low pressure warning comes on at 25 PSI and goes out again at 28 PSI.
The sensor has a build in battery and it is not replaceable. When a battery becomes low, you will get a "low battery" message with the location. There is a radio transmitter build in, which sends its data once a minute to the EVIC when driving at 25 MPH or faster for a mounted wheel and once an hour for a spare wheel.
The tire pressure is temperature dependent. The higher the outside temperature, the higher the tire pressure. (also a tire warms up when driving, which causes the pressure to rise. For that reason you should check the tire pressure on a cold tire), but also the colder it gets, the lower the tire pressure.

JeepMe 12-12-2012 03:36 PM

Re: Tire Air Pressure Sensors
 
25-26 psi is pretty low, I would air them up into the 30s.

Like Frank said, colder temperatures will mean less tire pressure because air becomes more dense when it's cold. However, if the tires are inflated with nitrogen (for tire shops around me, in South Central Indiana, Nitrogen is standard now) the pressure won't vary as much.

I had a buddy who also has TPMS on his vehicle (not a Jeep) and it went off. He couldn't figure it out b/c all 4 of his tires were at 35 psi. Turns out that his spare tire was low and that was causing the light. Make sure to check your spare.

Me Fix 12-12-2012 05:12 PM

Re: Tire Air Pressure Sensors
 
Thank you both for responding. I know about air density as the outside air cools, but I didn't know the window at 25 PSI on and 28 PSI off. Also I don't recall seeing the spare on the overhead information center. I will look for that, as well as checking the spare. I didn't do that when I rotated the tires, but i do know I have a origional spare on the rogue wheel which looks like it has never been on the road. I really like the wheels, but the four on the ground at this time have peeled the chrome off on the inside. I guess that has been or was an issue with those wheels.

Thanks again. I just love this site and all the members that make it what it is!

JeepMe 12-12-2012 09:09 PM

Re: Tire Air Pressure Sensors
 
Quote:

Originally Posted by Me Fix (Post 723735)
Thank you both for responding. I know about air density as the outside air cools, but I didn't know the window at 25 PSI on and 28 PSI off. Also I don't recall seeing the spare on the overhead information center. I will look for that, as well as checking the spare. I didn't do that when I rotated the tires, but i do know I have a origional spare on the rogue wheel which looks like it has never been on the road. I really like the wheels, but the four on the ground at this time have peeled the chrome off on the inside. I guess that has been or was an issue with those wheels.

Thanks again. I just love this site and all the members that make it what it is!

My buddies vehicle was not a Jeep, so maybe your spare doesn't have the sensors. But if your main tires are that low, chances are that the spare is also low.

mrjaydeeone 12-16-2012 08:39 AM

Re: Tire Air Pressure Sensors
 
I have an 04 and the spare tire does not have TPMS sensor. I believe I read somewhere that they discontinued the 5 tire system. Which year I forgot, and where I read I forgot also. But it is easy to determine if you have one on the 5th wheel, it would be a metal vavle stem like the other 4. Not a rubber one.

Me Fix 12-16-2012 11:20 AM

Re: Tire Air Pressure Sensors
 
Thanks again for responding. My spare does have a pressure sensor valve stem, but I do not see a spare reading in the overhead data center console. I think the system only looks at the four tires on ground. Per the suggestions, I again adjusted the pressure to 35 LBS. I only have a stick guage so they all are close per the readout. Perhaps when any of the four get out more than 4 PSI, the data center will alert me automatically. I'm pretty sure the spare is an origional and like the rim, both look brand new, but it's still a very good ide to check the pressure in the spare often. The spare has no value if it has no air! Having bought this Jeep used, I sometimes wonder just what has or has not been done. I do have the round magnet needed to find each tire after rotation. Lucky I guess!

harkinsc 12-16-2012 11:25 AM

Re: Tire Air Pressure Sensors
 
Quote:

Originally Posted by Me Fix (Post 725200)
Thanks again for responding. My spare does have a pressure sensor valve stem, but I do not see a spare reading in the overhead data center console. I think the system only looks at the four tires on ground. Per the suggestions, I again adjusted the pressure to 35 LBS. I only have a stick guage so they all are close per the readout. Perhaps when any of the four get out more than 4 PSI, the data center will alert me automatically. I'm pretty sure the spare is an origional and like the rim, both look brand new, but it's still a very good ide to check the pressure in the spare often. The spare has no value if it has no air! Having bought this Jeep used, I sometimes wonder just what has or has not been done. I do have the round magnet needed to find each tire after rotation. Lucky I guess!

In 2004 the TPMS in the EVIC was changed to a 4-tire system.
Cold tire pressure should be about 33 psi.

Gus9890 12-17-2012 12:27 AM

Re: Tire Air Pressure Sensors
 
The air temperature does make a big difference

robpp 12-18-2012 07:50 PM

Quote:

Originally Posted by Gus9890 (Post 725505)
The air temperature does make a big difference

DING DING

33 psi in your tire at 75 degrees is something like 28 psi at 35.

AMSOIL_Dealer 12-31-2012 07:36 PM

Re: Tire Air Pressure Sensors
 
My 2002 WJ has the monitor for the spare, but it will only display a warning low/high not current pressure as the other four. X 2 on the 33 cold psi.

Me Fix 01-02-2013 10:58 AM

Re: Tire Air Pressure Sensors
 
My Overland is a 2004 and it does look like it only displays the 4 on ground tires. After checking and setting the pressures at or as close to 35 PSI as I can with the stick guage I have and doing this in the heated garage, the EVIC is not giving me any fault readings like it was even after going outside with the temp down around 12 deg F. I do still wonder what PSI trips a "check tires" alarm. Maybe 25 PSI! I'm going to start another thread concerning my EVIC. Thanks Again to all who responded.


All times are GMT -5. The time now is 07:00 PM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community