Tire pressure monitor

[Hogwild501]

Just over a week into my h3 ownership and have experienced my first service light. Woke up Sunday and thought it would be a nice day to get see the fall foliage. Decided to go to Winona which is a huge national park area with endless logging roads and switchbacks. About an hour in, roughly 15 miles, we came to our first steep mountain. Upon reaching the top I was kinda excited that the h3 hadn't even slipped a tire. We got out at the top to enjoy the scenic view. When we climbed back in and started it up a "serv tpm" message appeared on the dash. Having to rack my brain for a minute I deduced that it had to mean tire pressure monitor. I got out checked all the tires. All air pressure was fine. Continued on our journey which consisted of almost four hours of steep climbs and decents. I checked air pressure a couple of more times and all was fine. H3 performed exceptionally well in my opinion. Has anyone else expericed this same issue. And if so how do you correct it.

 

[ArtHummer]

I've had the same problem on my 09H3. The light will come on and stay for few days, and then it is fine. I have this light come on about once a month. I've been to a dealer and they replaced the tire pressure sensor (the one that is in the wheel instead of regular rubber insert). That did not helped aether. After some time the light started to come on again. I got new tires and keep pressure at about 37psi. Now it is fine. I think the factory recommendation is about 38psi(please correct me if I'm wrong). But the light will come on of the if difference in the tire pressure is by 3 psi from all others. For example if one tire got 34 and other 37, this will set of the light.

 

[alrock]

SERV TPM should not come on for low tires; Low Tire will appear when tires are low.

The first troubleshooting step is to follow the procedure in the Owners Manual to retrain the system to recognize the four sensors. This is more commonly an issue when people do a five tire rotation. Note that starting in late 07 the H3s only came with four sensors; prior to that the spare also had one.

The H3 only recognizes four sensors at a time and they "turn on" with movement which is why the sensor in the spare, if it is one of the four recognized by the computer, could give you the SERV TPM error if the calibration has not been done.

It could also be a failing sensor which would of course need replacement. The battery is sealed within each unit and is not designed to be replaced except as part of the whole unit.

Not a safety issue as long as you verify that your tires are properly inflated.

 

[f5moab]

I've had the same problem on my 09H3. The light will come on and stay for few days, and then it is fine. I have this light come on about once a month. I've been to a dealer and they replaced the tire pressure sensor (the one that is in the wheel instead of regular rubber insert). That did not helped aether. After some time the light started to come on again. I got new tires and keep pressure at about 37psi. Now it is fine. I think the factory recommendation is about 38psi(please correct me if I'm wrong). But the light will come on of the if difference in the tire pressure is by 3 psi from all others. For example if one tire got 34 and other 37, this will set of the light.

TPM system does not do a comparison between sensors to see if a tire is low or not. Each sensor in each tire determines if the tire is low. (There was a system designed to determine if a wheel was low based on a wheel speed comparison with other wheels, however, the Federal government rejected it, and passed the law to require sensors in each tire on the ground.)

Just remember, it is getting colder out and that for each 10 degree drop in ambient air temp you will lose 1 pound of pressure in your tires. Now is the time of the year when someone gets in their vehicle early AM, and the low tire warning comes On, then they drive a few miles and the message goes Off. If a tire drops in pressure (or all tires) the system will state a low tire; however if the message in the DIC is SERV TPM that usually does not note a low tire, it notes a problem is sensed in the system by the BCM. It could be anything from a sensor not sending a signal to the BCM, to an internal circuit.

tire pressure on the tire placard on the B-pillar or at the top of the rocker (driver's door) is 35 psi for 285 tires; not sure about 265 size tires. So, if during the day, the ambient temp is around 80 degrees and you set the cold tire pressure to 35 psi, and during the night it drops to 20 degrees, you will drop approx. 6 psi; thus your low tire pressure warning will come on. Then you drive, tires heats up from friction, internal tire temps go up a few degrees, pressure goes up a few pounds, and warning will turn Off.

Simple fix...add a few pounds of air to each tire.

 

[Reloader]

Ya, do the horn honk hokey pokey relearn procedure. This will tell you if all 4 sensors on the ground are working.
KOEO, parking brake on, park lights on-off 4 times, horn will honk 2 times. Start with LF tire (LF marker lamp will turn on), bleed air from valve stem till horn honks once.
Next one is RF tire (light comes on), same thing. Then RR tire and finally LR tire which will end with a double honk. If horn does not honk and tire bleeds down to flat, thats a good indicator that wheel's sensor defective. If all 4 honk horn, air up tyres to 35psi and drive. If light and message disappear system has reset. In this cooler weather I need to keep tyres inflated to 38-40 psi to keep light off in morning. It also helped to bleed out all co2 left over in tyres from wheeling in Moab. Co2 seems to be effected more by the cold. I've seen sensors start to work again a few times after total bleed down of air. And fix-a-flat is a killer of TPMS sensors. Goos them up good. Sensors for GM vehicles are cheap and can be programmed using above procedure. Unlike Toyota sensors which are $130 each and $118 to reprogram system with the Techstream plus install labor.

Hope this helps.

 

[ALPHA of JONESY]

The problem you are having is exactly what I was experiencing a few months ago. Shortly after getting my new tires the SERV TPMS warning appeared so I refered to the manual and performed the relearn procedure. I had one wheel (LR) that would not respond so I went to my local Discount Tire where they verified that the sensor was not responding and then I had them replace it. It's been a couple of months now and I have no issues except for LOW TIRE PRESSURE, but that is because I installed 315's and I run them at 32psi.

 

[ArtHummer]

Co2 seems to be effected more by the cold.

Hmm, this is an interesting observation. All adds actually state that CO2 is not getting effected by tepms as much us air... If you say that on cold CO2 is acting up more, then what is it good for?
In any case, if you deflate and inflate tires regularly the CO2 is useless.

 

[Steve #1]

Hmm, this is an interesting observation. All adds actually state that CO2 is not getting effected by tepms as much us air... If you say that on cold CO2 is acting up more, then what is it good for?
In any case, if you deflate and inflate tires regularly the CO2 is useless.

You may be thinking of nitrogen. I tried nitrogen at one point to stop the early morning low pressure and can say it wasn't as bad as it was with air, but not worth the trouble especially if you ever air down.

 

[alrock]

Not sure about CO2 on a daily basis but when filling up from a tank you do need to overfill, presumably due to how cold the air is coming in.

 

[reaper]

My "serv tpm" light stays on... it's a feature. Consider yourself part of the TPM Elite.