ahh yes a TPMS question.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

No issue running without the sensors.

The light will just stay lit.

 

The light comes on at approx. >45psi and <30psi. So chances are when cold you are below 30psi and once the tire heats up the pressure rises.

 

If the person who takes your wheels changes tires the sensors are attached to the valve stems. Very easy to remove.

 

If the light does not bother you then that is the only "adverse" effect.

thanks for your advice thats all i need to know.

I dont care about the TPMS light being lit in the dash as long as nothing harm being done without the sensor.

 

I appreaciate it!

electric tape.

/thread

if the sensors are out of range of the vehicle, the light will flash. at least thats what my 08 did till i replaced them.

Thats a programming issue between the TPMS ECU and the sensors.

 

If the sensors are missing the light just stays lit. I even tested with the sensors out of the wheels. They work if you keep them in the cabin too, lol. In the trunk they work ok. You can keep them pretty far from the wheel wells and the sensors still work.

 

If the tire pressure is low/hi/or the sensors are missing the light stays lit. If the system sees a malfunction, the light blinks. Missing sensors is not a "malfunction" thankfully.

If the sensors are missing, I've personally seen both scenarios; lit constantly, and also blinking.

 

OTOH, when the pressures are low, it will remain lit constantly.

 

Not to go too far OT, but I've never heard that the light comes on when the pressure is too high, only too low. I've had these sensors installed even when running on the track where pressure can go up to 50 psi. The light never came on, but did if the pressure got too low.

 

Thats a programming issue between the TPMS ECU and the sensors.

 

If the sensors are missing the light just stays lit. I even tested with the sensors out of the wheels. They work if you keep them in the cabin too, lol. In the trunk they work ok. You can keep them pretty far from the wheel wells and the sensors still work.

 

If the tire pressure is low/hi/or the sensors are missing the light stays lit. If the system sees a malfunction, the light blinks. Missing sensors is not a "malfunction" thankfully.

Thats a programming issue between the TPMS ECU and the sensors.

 

If the sensors are missing the light just stays lit. I even tested with the sensors out of the wheels. They work if you keep them in the cabin too, lol. In the trunk they work ok. You can keep them pretty far from the wheel wells and the sensors still work.

 

If the tire pressure is low/hi/or the sensors are missing the light stays lit. If the system sees a malfunction, the light blinks. Missing sensors is not a "malfunction" thankfully.

 

So if the tpms are left off the wheel but in the car the light on the dash will stay off?

First. If you put 50 psi in the tires the light will come on. I did it to test.Second, when the system detects an issue the light flashes. After a minute it goes solid and stays until the issue is resolved.Third, yes. I drove with the sensors in the glove box, on the passenger seat, in the center console and in the trunk to test. Light never came on.

First. If you put 50 psi in the tires the light will come on. I did it to test.Second, when the system detects an issue the light flashes. After a minute it goes solid and stays until the issue is resolved.Third, yes. I drove with the sensors in the glove box, on the passenger seat, in the center console and in the trunk to test. Light never came on.

 

lol. How is that possible? I think it would flash or stay solid since it is not detecting air pressure.

 

If that is that case, that might be my solution to keeping the light of instead of getting a second set of tpms and having the dealership flash it everytime i change the wheels, I'll just keep the tpms in the glove box.

 

Can anyone else confirm this?

Ok I just traded my rims and I love the way my car looked now.

Now that it doesnt have any sensor on each wheel, the light blinks every 2 seconds and it doesnt bother me at all..just ignore it.

I guess nothing's gonna happen at all right? like on the CPU?

Light will stop blinking and go solid. Might need to restart the car to make it happen. No big deal. It is just a dummy light. Not interconnected with other systems.When I told a tire store about my experiment and findings they were not surprised. I was told many customers report the same thing. Leave the sensors in the car and the light stays off. I had all 4 sensors in a sandwich bag for my test.

 

Sorry posting from my Crackberry.

 

If you need specifics I can post better later, or shoot me a PM.

Awesome. This is the route I am going to go so when I put my winters on the light doesn't come on.

 

M sprank please post up more about this when you get home. I am very intrigued about this. I thought I was going to just switch over the TPMS over to my Rota's and deal with the light in th winter time, but if this is the case I'll leave them in my glove box.

Well...

 

I went to Americas Tire to have my OEM wheels and tires broke down to recover the sensors. They installed the sensors in 2 new wheels and handed me two sensors in a bag.

 

When I finally drove the car I had no sensors on the wheels, but two wheels with sensors in the trunk and two sensors in the center console. No light. Hmmm.

 

I called and asked Americas tire about the two sensors I did not have in hand. Are they in the newly mounted wheels? Why is my TPMS light saying the sensors are on the car? Americas tire says "because the sensors are in the car". They tell me that it happens all the time. Don't worry, if the sensors are in the car and not on the wheels the TPMS light will stay off, it is normal.

 

So, I drive to another Americas tire and have them break down the newly mounted wheels. Sure enough the TPMS are in there. I take the 4 TPMS sensors home in a bag.

 

I leave the bag at home and go for a drive. Light starts to blink, then goes solid. I drive for a day. Light stays on all day.

 

Next day I put the sensors (in the bag) in the car with me. Light goes off after a while. Drive all day, light stays off.

 

Now I am intrigued. I start moving the sensors around the car to see if the light goes back on. Nope.

 

Have the sensors installed in the 4 new wheels and tires (finally have the wheel fiasco figured out). With all 4 sensors installed set air pressure to 28 psi. Light blinks, then stays on. Set air pressure to 40psi. Light goes off after driving for a while. Set air pressure to 50psi. Light starts to blink then goes solid after driving for a while. Set air to my normal 42psi rear 40psi front and light goes off after driving for a while.

 

Call Subaru dealership. Ask Service Tech about TPMS. He says they are programmed for a low and high pressure response. He is not sure, but thinks the sensors might register if kept in the car.

 

Not the most scientific test, but in my case the TPMS light can be activated by under pressure and over pressure (tested in both my 2008 cars). In my SpecB I tested the moving of the sensors around the car. As long as they were in the car, the system responded normally.

 

No one could explain why the light did not come on since the sensors should be reading low air pressure while in the car. I was/am very confused by this.

 

If anyone has answers I too would love to know.

 

All I can say is it worked in my 2008 SpecB. Also, that Subaru confirmed a low and high pressure response from the system. That no damage is done by driving without the sensors. That the dummy light annoys me enough that the TPMS sensors are in both my cars wheels.

Wow. I am going to post this in the Rota Grvael thread and see if someone who is about the put their gravel's on would want to experiment with this theory of keeping the sensors in the car.

I find it very hard to believe that keeping sensors at zero pressure in the glove box does not produce TPMS light after significant driving.

 

Presence of TPMS signal at start-up might be enough not to trigger the light at start-up. Then the system needs about 10 minutes of driving to fully initialize. It is possible that your commute/driving pattern is just pretty short.

I commute 60 miles each way in LA traffic. I drove for hours not minutes. Thats why I was surprised.

 

I got wierded out enough to pull the sensors from my wheels and start testing. Still not sure how well the system works. How reliable can it be after what happened with my car? I thought for sure the system was broken. I was amazed when it started responding to under and over inflation again after being mounted back in the wheels.

 

Maybe my TPMS has Gremlins. Maybe it was made by Toyota even though the sensors have Subaru emblems on them. If so, the TPMS might be a death trap. IDK.

Well, if someone in MI is willing to lend me a sensor, I can test this theory

Maybe it's your tune, lol.

I'll put on a search on ebay for a sensor. If I can buy one for not more than a few bucks - I'll test it too.

Cost me $120 to break down the wheels and pull the sensors. Then reinstall sensors, mount and balance. $120 to find out the system appears to work, but not trust it.

 

Anyone else ever test?

I'm definitely not wasting more than $10-$15 for a spare sensor. Blew too much money on ATEQ&Autel tools already

bump.

I got a spare sensor off ebay. Hopefully by this weekend I'll have it delivered to play around. Now need to figure out a clean and simple way to get it into a pressurized container that I could carry in the car to make the sensor think its inside the wheel (to make the experiment similar to m sprank's) before taking it out.

Balloon? Mason jar with a fitting in the top?

 

Trying to think of household items with little modification.

Balloon? Mason jar with a fitting in the top?

 

Trying to think of household items with little modification.

Condom with a ziptie holding it shut.

Balloon? Mason jar with a fitting in the top?

Typical pressure in a baloon is barely above atmospheric. Maybe 2-3psi more at best, so that's like 17psi total, and I need more than 24 so that the system is in 'normal' mode at the start.

Trying to think of household items with little modification.

Yeah, that's the point

 

Condom with a ziptie holding it shut.

I wouldn't think that it would hold much more pressure than a baloon, but I'll check. I think there are/were standards of condom testing where they blow'em at some pressure and see if it holds...