TPMS on i-MiEVs

[cometboy]

Anyone played with TPMS on this forum?

All the U.S. i-MiEVs must have it as I think the U.S. Federal Regulations require that all new light vehicles sold in the U.S. since September 2007 be equipped with a Tire Pressure Monitoring System (TPMS). Our Australian delivered models do not have this even as an option.

Some questions:
- Is the sensor/xmitter in the valve stem?
- How is it powered and what is the battery life?
- How is it displayed?
- Is there an audio warning alarm?
- Is it a seperate black box or wired into the CAN bus? (I can not see any reference to it in my DVD workshop manual but it does not cover the US models)
- Just wondering if it is something that can be retro fitted or if aftermarket is the only option?

Thanks
Bruce

 

[PV1]

The only display of the TPMS is a warning light for low pressure. I'm pretty sure they are valve stem type.

 

[iMiEVNZ7]

http://avetechnology.en.alibaba.com/product/1531414488-210570673/TPMS_AVE_Color_LCD_Cool_TPMS_for_Lexus_Tyre_Pressure_Monitoring_System_AVE_TPMS_have_2nd_pressure_suitable_for_Off_road.html


Looks pretty cool. Note sensors inside rim... Might need to remove tire to change batteries ?. I would have thought a movement based recharging system might be an idea.

http://i01.i.aliimg.com/img/pb/714/926/267/1284896315125_hz-myalibaba-web13_5192.jpg

 

[Don]

The batteries last a long time (several years) because the system is only in operation when the wheels are turning. It would probably be advisable to change them when you buy new tires - New valve stems and new TPMS batteries

Don

 

[Barbagris]

My Euro-clon don't have TPMS. But it's possible to mount one in a car without sensors on the rim. A low pressure wheel present shorter effective radius, and if ABS sensor realizes one wheel is spinning faster than the others... Alarm!

See "indirect TPMS" or iTPMS in the wikipedia:

http://en.wikipedia.org/wiki/Tire-pressure_monitoring_system

 

[PV1]

Barbagris, the GM EV1 had that feature. I guess it ties into the steering position sensor, or otherwise it would warn you of low pressure every time you turned the wheel.

Wouldn't work too well if all four tires were low. :lol:

 

[Slicke]

The batteries last a long time (several years) because the system is only in operation when the wheels are turning. It would probably be advisable to change them when you buy new tires - New valve stems and new TPMS batteries

Don

Does the battery lose it's power if you don't drive it for a while?

 

[Don]

No more than a lithium battery sitting on a shelf - There's no current draw on the battery if the vehicle isn't moving

I noticed on my Ford alloy wheels, they machined away some aluminum on either side of the valve stem - I surmise this is to make up for the weight of the sensor on the valve stem so it doesn't cause an imbalance which would need to be corrected by adding extra weights on the opposite side of the wheels. Not sure if the iMiEV wheels are the same or not

Don

 

[jray3]

A downside to our TPMS is that they have to be individually linked to the car, and my local tire shop couldn't do it, though they thought they had all the latest tools and software updates... The dealer of course wants a pound of flesh every time, so TPMS is only active on my winter wheels, and not the summer set.

 

[Don]

Ours is simple compared to my Ford - On it, each individual wheel is separately linked, so just rotating tires requires that you 'relearn' the position of each wheel. Luckily, you can do this yourself and not have to pay the 'dealer minimum' . . . . a strange name which allows charging $100 for 5 minutes work

Don

 

[phb10186]

So glad the UK doesn't mandate TPMS... what a useless technology. So glad the IMIEV UKDM doesnt have it fitted.

Both my parents-in laws had BMWs, both constantly giving trouble with TPMS... hopeless.

 

[Don]

Like most other enthusiasts, I don't think *I* need it, but a walk through a WalMart parking lot looking at tires will make you think it's probably an excellent idea for most people - There are a LOT of seriously underinflated tires running around on cars out there and most folks aren't aware that overheating a tire just once can destroy it's layup - When they finally see it's nearly flat, they fill it up with air and don't give it another thought . . . . until they have a blow-out doing 80 down the freeway a month or two later

We had some work done on our iMiEV at a body shop and when I picked up the car, the TPMS light was on - The thoughtful mechanic had checked the tire pressures and finding all 4 of them too high, he had reset all 4 tires to 30 psi. I might not have noticed it for some time had it not been for the light on the dash. I filled them up to 40 as soon as I got it home. On our Ford, the recommended pressures are 40 front and 42 rear - When the TPMS light comes on at 36 psi, all 4 tires still *look* to be equally inflated, so an average person who just looks at his tires thinking them to be OK will be really misled. You *should* check your tire pressures once a month, but as we know, not 1 in 10 drivers actually does so. How many households even own an air compressor? In the USA, it's pretty rare to find a service station which has an air machine these days, so most folks never think about it

TPMS systems may be a pain for some - I don't see why if it's functioning correctly - but mandating it on every car sold is a really good idea, IMO - No doubt it save lots of lives. I don't want the guy coming at me on a two lane road to blow a tire and take me out due to his ignorance

You may not have it in the UK yet, but it's coming, I guarantee you

Don

 

[PV1]

He thought 40 PSI was too high on the i-MiEV? With the way the front tires bulge, I feel 40 is too low when I look at them (I know it's not, but still concerns me).

My warning light comes on when it gets really cold. I don't think I got a nitrogen fill the last time I had tires put on. The light's never come on before this set of tires, and yes, I've checked the pressure (all above 36 PSI at 50 F).

 

[phb10186]

Like most other enthusiasts, I don't think *I* need it, but a walk through a WalMart parking lot looking at tires will make you think it's probably an excellent idea for most people - There are a LOT of seriously underinflated tires running around on cars out there and most folks aren't aware that overheating a tire just once can destroy it's layup - When they finally see it's nearly flat, they fill it up with air and don't give it another thought . . . . until they have a blow-out doing 80 down the freeway a month or two later

We had some work done on our iMiEV at a body shop and when I picked up the car, the TPMS light was on - The thoughtful mechanic had checked the tire pressures and finding all 4 of them too high, he had reset all 4 tires to 30 psi. I might not have noticed it for some time had it not been for the light on the dash. I filled them up to 40 as soon as I got it home. On our Ford, the recommended pressures are 40 front and 42 rear - When the TPMS light comes on at 36 psi, all 4 tires still *look* to be equally inflated, so an average person who just looks at his tires thinking them to be OK will be really misled. You *should* check your tire pressures once a month, but as we know, not 1 in 10 drivers actually does so. How many households even own an air compressor? In the USA, it's pretty rare to find a service station which has an air machine these days, so most folks never think about it

TPMS systems may be a pain for some - I don't see why if it's functioning correctly - but mandating it on every car sold is a really good idea, IMO - No doubt it save lots of lives. I don't want the guy coming at me on a two lane road to blow a tire and take me out due to his ignorance

You may not have it in the UK yet, but it's coming, I guarantee you

Don

Oh we have it alright - its fitted to every new car pretty much, it's just not mandated by law yet I don't think. Yeah, those are all good points I agree. It's a good idea on motorbikes actually, but those don't seem to ever have them.

I guess I look at things in a utilitarian manner - simple and high quality wins it for me, rather than over complex and less good quality.

My particular hate of TPMS is for two reasons:

1. The design I have seen is a wireless sensor on the inside rim valve side - so, what you have to take the tyre off to change the battery??? if so, thats a real pain.

2. On the BMW TPMS (which to be fair is all i've had experience with, but must be a fairly widespread system), a slightly deflated tyre gives an orange warning light on the dash, and a 'flat' gives a red (I think they permanently go orange when the battery goes low/ malfunction)... which means, in the UK anyway, that it would fail (or throw an advisory at least) on the UK equivalent of the yearly inspection test... in the same way an ABS warning light does... and that''s just a right pain if it falls at yearly test time, as you could be left with a car that is legally not fit for the road, when the exact same car without TPMS would be fine.... sensors...

Of course, if you can totally disable the entire system, then that at least gives owners the option.

Is it still the case in most states, that other than a smog test, it's the drivers liability to ensure the car is roadworthy - thus if you have an accident, you could be in a bundle of trouble if, for example a tyre is bald? If so, it's totally the opposite in the UK (and likely Europe) - here, the every vehicle has to have a yearly inspection covering the lot once the car is 3 years old, and it's illegal to drive unless it passes (or it's fixed within I think 7 days of a fail and retested to pass)... fairly safe system - but they look at a lot of stuff: tyres, brakes, emissions (for ICE), suspension, corrosion, lights, wipers, fuel lines, oil leaks, cracks in the windshield etc etc.

Any car with a crack more than 1/2 inch wide in the front windshield fails, and has to have a new one - one thing I notice every time I go to the states is the number of cars running with cracked windshields... all would be 'unfit for the road' in the UK, by definition of those laws.

Oh.. TPMS is now enshrined in to EU law...

http://www.evo.co.uk/news/16102/new-tpms-law-could-make-your-car-fail-its-mot

 

[wmcbrine]

2. On the BMW TPMS (which to be fair is all i've had experience with, but must be a fairly widespread system), a slightly deflated tyre gives an orange warning light on the dash, and a 'flat' gives a red (I think they permanently go orange when the battery goes low/ malfunction)... which means, in the UK anyway, that it would fail (or throw an advisory at least) on the UK equivalent of the yearly inspection test... in the same way an ABS warning light does... and that''s just a right pain if it falls at yearly test time, as you could be left with a car that is legally not fit for the road, when the exact same car without TPMS would be fine.... sensors...

Even if you did hit a sensor error near the time of the inspection, surely you could remedy it before taking the car in? This just strikes me as an unlikely problem.

Is it still the case in most states, that other than a smog test, it's the drivers liability to ensure the car is roadworthy

It is that way here in Maryland -- one inspection when the car is brought into the state; otherwise nothing but emissions tests -- but it wasn't that way in previous states where I lived, which had annual inspections.

I found a list: https://en.wikipedia.org/wiki/Vehicle_inspection_in_the_United_States

Apparently you're right, there is no periodic safety check in a majority of states. But many do have it.

 

[Don]

We used to have an annual 'inspection' here in Mississippi - It cost just $5 and if your lights, turn signals, wipers and horn worked, you passed. Took all of 5 minutes and checked nothing of importance . . . . tires, brakes, shocks, seatbelts, airbag lights, etc. We've never had any smog checks . . . you could bring in a car that burned a quart of oil every 100 miles and if the lights and wipers functioned, you passed. They did away with all inspections a couple years ago, finally admitting they were useless, but they didn't replace it with anything

I'm very familiar with the strict inspections in Germany when I was stationed there - Your car had to be in VERY good shape or you couldn't license it and they checked EVERYTHING!

Don

 

[phb10186]

We used to have an annual 'inspection' here in Mississippi - It cost just $5 and if your lights, turn signals, wipers and horn worked, you passed. Took all of 5 minutes and checked nothing of importance . . . . tires, brakes, shocks, seatbelts, airbag lights, etc. We've never had any smog checks . . . you could bring in a car that burned a quart of oil every 100 miles and if the lights and wipers functioned, you passed. They did away with all inspections a couple years ago, finally admitting they were useless, but they didn't replace it with anything

I'm very familiar with the strict inspections in Germany when I was stationed there - Your car had to be in VERY good shape or you couldn't license it and they checked EVERYTHING!

Don

It's the same in the UK as it is in Germany... Though I think in Germany you can teen have non factory fitment wheels or different tyre sizes... so we may be slightly less strict here... but the emissions and other safety tests are euro wide... they get stricter every year, though not retrospectively, as older cars have to meet their year respective standards.

The emissions test CO, hydrocarbons, and lambda at idle and 1500rpm I think (fast idle)... so you have to be in check on all those... it's these standards that have killed off diesels, which is probably no bad thing actually.

Even if the car is tested and passes, the driver still has to ensure the car is roadworthy...

Surprised there are no inspections in many US states still... very surprised.

They gave me an advisory on the Imiev last month because, amazingly, at 5 years of age, the VIN plate has started corroding... never had anything like that before... I called Mitsubishi, and they never got back to me... but essentially it's the one truly unique part of the car. Also, and very annoyingly, I wouldn't be able to change it myself, as it has certain rivets that need the dealer to do, and a letter covering any queries... so my reply to the tester was that I'll have to take the cover in the trunk off in future and he can read it off the chassis... wouldn't want him to suspect the car was cloned in anyway cos there are literally thousands of silver IMIEVs! ! (actually a big issue in the UK)...

Clearly, if you have strict emissions tests, it's not difficult to swap the plates on a same model and colour... especially on something common. Here, you can order a set of legal plates on ebay, without any documentation, as the plates are benign, and other than display the license number, are not used for anything like adding stickers to show an inspection pass.

On the I, I simply unscrewed the plates fromy Celica once I had the number swapped over from the one that was on the I when I bought it (only cos I wanted my specific number)

 

[jray3]

Has anyone found a DIY tool to link the TPMS sensors to the car? I'm about to change wheels for the season and don't want to pay the dealer penalty, but would like to get rid of that annoying error light. Dunno if this is within the CarSoft i909 capabilities....

Ditto on the USA's lack of vehicle inspections. I was dismayed upon moving to the Pacific Northwest that though there are strict emissions inspections here around Seattle and Portland, there is no safety component to the test...

 

[Don]

My warning light comes on when it gets really cold. I don't think I got a nitrogen fill the last time I had tires put on. The light's never come on before this set of tires, and yes, I've checked the pressure (all above 36 PSI at 50 F).

Same thing happened to us over the weekend. TPMS light is on my wife's car even though the tire pressures were all at 40 psi or a little higher. First time I've noticed this - Outside temp was around 30 overnight the past couple days

Don

 

[jray3]

I saw the TPMS light before replacing a worn set of Enasaves with snow tires last week. Pressure in the old tires was a mite low, but I also meant to have the sensor batteries replaced under the thinking that in cold weather an aged sensor battery voltage could droop, affecting the reading in addition to the pressure drop that happens when tires get cold. So far, no warning light with the properly pressurized new tires and TPMS batteries approaching 6 years old.