quote:

Originally posted by David Lee:

quote:

Originally posted by Oz_Shadow:
The dealer quoted me $900 to replace my Subaru sensors. I passed. Going old school!

That is incredible. Why so expensive?

Parts: each front 180, each rear 190, programming labor $100

I think those parts prices included labor too, but I didn’t even ask for details at those prices.

I will have to check with my tech but I haven't heard him say there was an issue with Subaru. We install new sensors for $65 per wheel.

quote:

Originally posted by David Lee:

quote:

Originally posted by Oz_Shadow:
The dealer quoted me $900 to replace my Subaru sensors. I passed. Going old school!

That is incredible. Why so expensive?

See the reason in BOLD.

My local tire shop will replace at $60 each - never go to the dealer

quote:

Originally posted by sgalczyn:

quote:

Originally posted by David Lee:

quote:

Originally posted by Oz_Shadow:
The dealer quoted me $900 to replace my Subaru sensors. I passed. Going old school!

That is incredible. Why so expensive?

See the reason in BOLD.

My local tire shop will replace at $60 each - never go to the dealer

I didn’t get into the particulars. I have no idea how rears could be more unless they have some receiver they were replacing too. I only asked while I was doing the airbag recall.

I'm in the business, and while I don't get directly involved with the tire end, I don't know of any TPMS problems unique to Subaru. Any tire shop worth their salt should be able to handle them.

quote:

Originally posted by David Lee:
They got batteries in them. Could be one of two different kinds of batteries. I needed to have one of my new tires plugged a 2nd time.. Now I am going to replace the tire. Both punctures out in the no repair zone. Driving on the Flea Market property is hazardous. So the bad tire lost a bunch of air when temps here dropped down. Blew it back up and its holding air now. The TPMS dash light is staying on now. A friends Rav 4 had a rear mounted spare on its door mount which went low air pressure. Her dash warning light came on. Pretty tech. I am starting to think my sensor may have a bad battery. What do you know of TPMS sensors?

David, recently the TPMS light on my 4Runner came on. Sucks because unlike the VW Golf, it doesn't show you which tire is the problem. Doing a walk around didn't produce any concerns as each tire looked as normal. Once I threw the Milton tire pressure gauge on each of the tires, I noticed that each tire was at 27 psi. Vehicle calls for 32 front and rear. I put the correct amount into each one and no more issues. Kinda crazy that every single tire was 5 psi low, but they were. Just gotta keep an eye on them when the temps pick back up this week. I hope that you are able to find a solution that works.

I never replaced a single TPMS in my 2008 Expedition for the 10.5 years that I owned it. Not a single alarm.

quote:

Originally posted by Pipe Smoker:

quote:

Originally posted by David Lee:
They got batteries in them.
<snip>

I suspect that the TPMS of my 2018 Hyundai Sonata Limited doesn’t have any batteries. I think it’s powered by piezoelectric devices or an induction system. I.e. a coil and rectifier in the tire passes by a fixed magnet.

The reason for my suspicion: The display doesn’t report tire pressure until I’ve driven a quarter mile or so. Does that guess sound reasonable?

Making a wild ass guess here, but I would say no to the induction system you are hypothesizing. I would guess that it is just a program setting that delays displaying tire pressure until tires have "stabilized" so that you don't get a bunch of false initial readings.

They have a "roll switch" that has them transmit only hen rotating to preserve battery life. Per Wickipedia.

"The pressure, temperature and acceleration sensors generate analog signals which are converted to their digital equivalents using analog to digital converters. The acceleration sensor measures the centrifugal force generated when the wheel rotates. This force is proportional to the rotational speed. The acceleration sensor may be a simple switch rather than an analog transducer (accelerometer). This is usually referred to as a roll switch. The acceleration sensor allows the TPM to be placed in a low-power communication device mode, when the vehicle is stationary which can extend the battery life. The advantage of a roll switch over an accelerometer is that the switch is purely mechanical and doesn't use any power to take a measurement."

quote:

Originally posted by BurtonRW:
Try the ones made by Initrode if you can’t find Initech units.

"If you could just take care of that, that'd be great."

quote:

Originally posted by truckola:
They have a "roll switch" that has them transmit only hen rotating to preserve battery life.
<snip>

Thank you.

That’s probably the reason that my Sonata’s TPMS doesn’t report tire pressure until I’ve driven a quarter mile or so. The pressure reports exactly agree with my Milton S-921.

quote:

Originally posted by mutedblade:

quote:

Originally posted by David Lee:
They got batteries in them. Could be one of two different kinds of batteries. I needed to have one of my new tires plugged a 2nd time.. Now I am going to replace the tire. Both punctures out in the no repair zone. Driving on the Flea Market property is hazardous. So the bad tire lost a bunch of air when temps here dropped down. Blew it back up and its holding air now. The TPMS dash light is staying on now. A friends Rav 4 had a rear mounted spare on its door mount which went low air pressure. Her dash warning light came on. Pretty tech. I am starting to think my sensor may have a bad battery. What do you know of TPMS sensors?

David, recently the TPMS light on my 4Runner came on. Sucks because unlike the VW Golf, it doesn't show you which tire is the problem. Doing a walk around didn't produce any concerns as each tire looked as normal. Once I threw the Milton tire pressure gauge on each of the tires, I noticed that each tire was at 27 psi. Vehicle calls for 32 front and rear. I put the correct amount into each one and no more issues. Kinda crazy that every single tire was 5 psi low, but they were. Just gotta keep an eye on them when the temps pick back up this week. I hope that you are able to find a solution that works.

Nice that your tires were consistant in pressure. I think in cold weather tires tend to lose pressure. Opposite in Summer. My Cooper CS5s are much the same. One of the 4 just wasn't meant to be. I will buy another. Next set of tires I will replace my sensors too.

quote:

Originally posted by David Lee:
I think in cold weather tires tend to lose pressure. Opposite in Summer.

Boyle's Law.

Unless your state requires TPMS to pass vehicle inspection, rip those bastards out after they reach end of life. They're stupid to begin with, and don't raise until the tire is already 5 or more below vehicle recommended pressure, and that also is often lower than it should be. Apparently ride comfort is more important than performance or safety. After one or more goes bad, ask your tire man to replace them with good old fashioned rubber valve stems. If they don't make sound and you can live with the stupid TPMS dash light, just ignore it. I researched it and it's not apparent there is a way to disable that alarm programmatically.

I got my new tire mounted this morning. They did good work. Sensor light is out. The garage didnt charge me much for the work. Offered him a extra 10 bucks and he wouldnt take it. Very fair and kind people. Now if I just stay away from the hardware dumping zones at the Market.

The batteries last awhile. I bought my daughter a set of snow tires and wheels and skipped the tpms sensor. It required a $280 tool so the Subaru can relearn them. So this winter she dealt with the light in the dash. Swapped her summers back on and after a short drive her car figured out which tire was wear. Her’s show the actual pressure.

I recoded my BMW to show temperature and pressure.

Both cars read no pressure upon startup and registers after driving a short distance to “wake up”