Another LTPWS question...

[WradDad]

My car did not come from the factory with the UJ6 LTPWS option, at least according to the options list on the car. I'm the fifth owner of the car

I had the Vette at Willow Springs Raceway this weekend, and wound up having a wild ride off-track. Nothing seriously damaged, but I picked up a small rock between the rim and bead of the left rear tire. When the tire shop dismounted the tire from the rim to clear the rocks out, there was a white plastic box mounted to the inside of the rim with the biggest hose clamp I'd ever seen! I was in a hurry to get the tire mounted back up, so I didn't take the time to really check the thing out.

What could it possibly be? Is it possible that GM mounted plastic boxes on every rim, but only put the sensors inside the ones going on cars with LTPWS? Or maybe some sort of aftermarket system?

The only other thing I can think is that the wheel was aquired aftermarket, although it is the correct wheel for my Collector Edition.

Sorry for the long post, and your opinions are very much appreciated.

 

[Tuna]

The only thing I've ever seen mounted inside a Vette wheel like that have been the tire pressure sensors. GM never wastes money of unseen fluff, so it's probably not a dummy box.

One of the previous owners may have swapped wheels with someone else and ended up with sensors in one or more wheels. If the receiver is not installed, they will not work.

Without breaking down the wheels again, there is no way to tell what you have inside or how many you have.

 

[WradDad]

Well, I'll be due for tires in a month or two, so I'll find out at that point how many wheels have sensors.

Is there something I can look for under the dash to see if the receiver is there?

Thanks

 

[Rabbit]

Usually the transmitters are colored & I don't believe white is one of the colors unless it's an aftermaket someting or other. There's nothing under the dash the receiver is buried behinf the DIC.

 

[WradDad]

Thanks for the info. I can't wait to see what's behind doors number 2,3 and 4!

 

[Tuna]

Since you don't have UJ6 on the RPO list and, I'm guessing, you don't see a LTPWS light during start-up self-test, you don't have a factory system.

Is there an additional light on the dash, console, etc. that you can't figure out?

As Rabbit said, white doesn't sound like a factory color.

I'll be interesting to hear what you find.

 

[WradDad]

Tuna, you're right, no LTPWS light when I start the car. Also, no other lights I can't explain. The thing that's blowing me away is, What the heck is that thing on my wheel?! I'm almost to the point now where I want to have all the tires dismounted, just to see what's there!

I'm going to try to resist the urge until I get new tires. I'll let you know what I find.

Barry

 

[vietvett]

I did not think I had the LTPWS untill I replaced the rear tires ,The previous owner had taken the lamps out of the dash console to eliminate the warning light on my 96CE ,which told me i had a bad sensor on the front right tire when I put bulbs in the DTC

 

[Vettelt193]

It sounds like the aftermarket system that ecklers/mid america sells. That uses a white plastic box as described.

 

[WradDad]

The aftermarket LTPWS...

Would you happen to have a part number for that? I did a quick check of the Ecklers and Mid America web sites, and didn't come up with anything.

If my car was fitted with an aftermarket system at some time in it's past, I'd really like to try to get some information about it.

Thanks for all the info folks!

Barry

 

[Vettelt193]

maybe they stopped carrying it.... this is the closest i have found it looks very similar to the one i remember in the catalog, but i don't think it is the same one. the one in the catalog had a white box strapped to the wheel, and from what i remember had not only pressure, but temperature as well. if it helps you find more info, they also had a unit for trailers, to monitor the tires on those too.

http://autodax.com/products/tirepress/tire-pressure.htm

 

[vietvett]

You may want to check the two lamps that are in the DTC they are located in the top right corner they may be burnt out or the may be missing like mine were :duh

 

[compyelc4]

White (or cream color) is the stock sensor color on my '95. The large hose clamp actually helps seal a small plastic cover on the bottom of the sensor. You can easily remove the cover with a fingernail. Inside you will find a small circuit board. Two of the main components of the board are:

1. An air pressure sensor, and 2. A rad gizmo that creates an electric field each time the tire rotates. This electric field creates an electric pulse that is sent to the LTPWS signaling when air pressure reaches 25 lbs. or so. I'm not certain about the trigger pressure. Did you ever wonder how a tire pressure sensor sealed inside the tire/wheel combo sends a signal? Obviously a battery would not be a good idea as it would have to be changed from time to time. Thus the small electric generator.

When you operate a wheel without the sensor in place, your optional LWPS system will trigger an "LWPS" system failure light, and believe it or not, if you happen to have that sensor in your hand (as I had recently) and shake it once underway, instead of an LWPS system failure, that small shake will energize the signal generator and set a low tire pressure warning light instead. BELIEVE IT OR NOT! Recently I installed a tire without the sensor because I was in a hurry to use the car and I did not want to pay the $210 replacement charge for a new sensor/strap assy. GM quoted me that $210 for a strap/sensor assy. It seems that a goon once removed the tire to install a patch before I purchased the car with 12,000 miles on her. When he popped the tire rim from the wheel he ripped the sensor and strap right off. That assembly was rattling around inside my wheel for about 10,000 miles, but I never heard a thing. It just felt like a broken belt (kind of a wah, wah, wah, at 40 mph or better. I never could get that tire balanced right because each time I applied brakes the sensor assembly fell to the bottom of the tire in a different position. Then the centrifugal force held the assy in that new position until I stopped again! My tire started to wear really weird. When I replaced that tire recently the shop called that problem to my attention! I wonder how tires are removed from the rims without breaking that sensor and strap. I guess more care than usual is necessary. You can bet that when I replace the other three tires I will tell a non-Corvette shop about that sensor.

PS - Instead of springing for a new sensor/strap assy, I had the strap welded for $20.

Ted

 

[WradDad]

Thanks for that great information Ted.

You actually raised another question for me. I have read elsewhere that wheels equiped with the sensor have a sticker on the outside indicating the location of the sensor within the wheel, so that tire shops would know where not to place the bead buster. I don't have any stickers on my wheels, but the thing I saw on my rim was roughly opposite the tire stem.

Does anyone know if there's a "default" or standard location for the sensor to be located?

Thanks again!

 

[Rabbit]

Opposite the valve stem is correct.

 

[compyelc4]

..........and another thing..........

Fastened to the hose clamp, opposite side of the sending unit, is a flat 1"x5" (or thereabouts) counter-weight. Makes sense to me!