auradeus

I have a 2008 stock JK. Only 88K miles. The TMPS indicator light has been coming on with every start and stays solid. All tires read 35PSI including the spare (used a good reliable gauge, including a double check at a tire shop). The TMPS sensors were all tested at a tire shop (including the spare) and passed testing. I have driven over 50 miles and I disconnected the battery too. Still stays on.

Haven't had any other weird behavior that would suggest a computer issue.

Only thing I can think of, most of the TPMS sensors are originals, making them 11 years old. I believe they should have died a long time ago, average of seven years? If the sensor batteries are severely low, but intermittently responding, it could be triggering the indicator light but passing the testing of the sensors. I feel like that's a stretch though.

Any ideas? Thanks all.

LC Boyer

I had to replace mine when they were 5 years old. I kept getting low tire warnings

resharp001

idk about this. I have a couple vehicles that are '06 and '08 (not jeeps), and those original TPMS are still going strong. I think the idea of them going out intermittently though is a real stretch for sure. Had one of them dipped down at all to trigger the alert? I know this sounds like the ole "reboot" advice when having a computer problem, but since it's free I'd try adding a few PSI to each tire to get it well above the threshold for a couple drives and see if makes any difference. I believe they need to be 3psi over the threshold to reset. I can't recall what the factory threshold is, but if it's 32 and you're at 35, I can see how you might be in a grey zone if one of them actually did trigger the alert. I might be daydreaming, but that is what I'd try first if it were mine.

auradeus

I'm going to try this. I brought all the tires down to 30 PSI. I'll drive it around. Then I'll bring it up to 40 PSI. I figure that will "turn the switch on and off." No one can figure this out. The dealer says its the aftermarket remote starter (of course). The front end guy says no way it's the remote starter, the wiring schematic on my model has no relationship with TPMS, and the tire shop thinks its because of aftermarket TPMS sensors (no way). I'll kiss my own ass if my idea works at this point.

Mr.T

The door placard likely says 37 psi front/rear, and the stock TPMS alert level isn't much lower -- There's a deadband plus the some error tolerances too. If 35 PSI cold is what you want, best to set the TPMS threshold to around 28-30 psi.

auradeus

My door says 35 but understand your point. I may get a Procal to set the threshold lower. I suppose to test if this is the issue I could temporarily pump up to 39-40.

Mr.T

Yep, test at 40 psi -- It may take a few miles to reset (if that's the problem).

karls10jk

The solid light indicates a certain failure. You said in the first post that you've got the original sensors but later down the way you mention aftermarket sensors? They did make a frequency change somewhere in the years and you may be running into that issue if you've got aftermarket sensors.

As far as age of sensors goes- I had sensors fail on my 2009 VW but it also had plenty more miles than you. The sensors only wake up and report when they're spinning.

I cheated the whole process though and turned off the sensors so I wouldn't have to keep moving them between wheels and tires which I for some foolish reason, I change frequently.

auradeus

What specific failure does the solid indicator refer to in your experience? Multiple technicians have searched for codes and all is clear. They all say the vehicle is behaving as if the sensors are reading a lower pressure. They are also able to see the sensors as responding when they plug into the OBD II port, they can even read the serial numbers on the sensors through their module. So I have to think the aftermarket/frequency issue isn't the problem. At this point all I can think of as possible causes:
1) The tires simply need a little more pressure than what the door says in order to work. Maybe the door says 35 PSI but the configuration is 37. I'm gonna go to the shop and ask them to pump up to 40.
2) There is something wrong with the wireless ignition node (WIN). The TPMS system I have consists of 5 sensors, the WIN, and the indicator light (basic TPMS). This was replaced recently though due to a sentry key issue, but the TPMS issue did not coincide with that repair, but could have contributed to #3 below.
3) There is crosstalk in the wiring, i.e. something is sending an electrical current to the indicator light when there isn't actually a system fault.
4) There is some kind of weird electric interference on my jeep. Some piece of metal stuck somewhere in the chassis. I can't find anything when I look at the undercarriage but could ask my front end guy to put it on a lift and check around.

karls10jk

Again, I haven't had that light in about 9 years now....on my 2010. We removed the sensors from the wheels of my girlfriend's jeep and she had the steady light, as though nothing was in there, because there wasn't. I've seen low tires blink.

My recommendation is to find the recent post by Discount Tire and see what exactly they quoted on the status of the lights. I could search but it takes ten times longer on my phone than the internet and I'm not willing to put in that much effort, sorry.

I would still verify that the sensors are indeed the correct sensor for your year. Being in/ around a populous area, maybe you could swap tires with someone in a local club and see what effect it has on your light.