So I have a 2008 Pacifica that was showing signs of the TPMS batteries dying - randomly lose tire pressure indication on 2 of the 4 tires, and then sometimes getting them back, and losing them again. I made the mistake (water under the bridge) of buying no-name TPMS replacements off of Ebay.

I had read that the 2008 will auto-register the new TPMS sensors, so I thought it would be no problem.

So, after installing them, they display a very repeated pattern of not working correctly, and eventually displaying the "Service Tire System Soon" message.

Every morning and afternoon after work, the sensors all read correctly for like the first 10 miles of driving. Then, at about the 10 mile point, the display changes to "Service Tire System Soon". Sometimes I get a loud "Ding" when it does this, and other times it does it quietly. If I hit the STEP or RESET button, it will again correctly display the four tire pressures, but only for about 1 minute before reverting quietly back to SERVICE TIRE SYSTEM display.

Am I just screwed for buying cheap Ebay TPMS sensors, or is there something that a Chrysler dealership can do to make the vehicle permanently recognize these sensors as legit? I don't want to spend money for them to hook up some expensive tool, and then tell me "there's nothing we can do".

I will add that very rarely, one of the TPMS sensor drops out and I get a pressure of "--", but it usually changes back fairly quickly.

Thanks for any helpful comment.s

 

What are the pressures that you're setting the tires at? IF you overinflate the tires and they DO increase press from heating up while driving, they could be doing as stated from too high a reading. Use vehicle posted settings ...NOT tire max pressure rating on the sidewalls.

 

The moment you tell the dealer that you have aftermarket sensors in there the only thing that they will tell you is that they need to start off by replacing those with the correct OEM parts, otherwise they will in a worst case scenario just put it in the shop and waste a lot of time and your money on it.

As Rebel59 said, correct tire inflation with those is critical as the air in the tires can increase with tire temperatures. I have seen them increase on average between 2 and 4 PSI on a warm day in a surprisingly short period of time.
Anything over roughly four pounds high or low will trigger the system and turn on the warning light, so if your van is supposed to have say, 28 psi (Just a random number) then you need to make sure with an accurate tire pressure gauge that they are all 28 +/- 1 PSI when the tires are cold. No driving beforehand.
Since you have aftermarket sensors in it now, there is no way that you can trust the pressure that they display, until you have checked it against a good accurate tire pressure gauge.

This would be why I never buy aftermarket parts for cars, because now you are in a situation where you have no way of knowing if the sensors are useless crap, or that you have some other issue.

 

I have a 2008 Pacifica LTD 4.0L & had same intermittent prob w/2 sensors when I hit approx 130k mi. Took to my mechanic who said I needed to replace all 4 or I’d end up w/prob similar to yours. Haven’t had any probs in last 5 mos since he installed them.

 

As a last update on this, I bough some used factory original TPMS sensors off of Ebay for $14/piece. I installed them myself using a cheap harbor-freight bead breaker, and little strips of wood to hold the tire pinched down so I could get at the sensor and unthread the valve stem. All four of the sensors self-registered when I restarted the vehicle, and my tire pressure system works all the time now. I have no idea how long the batteries will last in "used" TPMS sensors, but its an easy enough task that I don't mind spending $14 dollars to make the problem go away again. With my Pacifica at 184K+ miles, I don't see needing many years of service, but you never know.