Just had my front tires replaced and here we go again. My light "LTPWS" is on initially goes out after a hundred yards always did that, and then comes back on. It seems to take longer to come on again, that's a good sign, but is it normal or FUBR.

 

What's LTPWS? Sorry, is it a low traction indication. Sounds like a bad sensor?

 

Low Tire Pressure Warning System.

 

When mine did that it was a bad sensor. The techs may have damaged it when they changed the tires.

 

Presume your talking about your 1991. Further presume you mean the 'service LTPWS' light and not the 'low/flat tire' light.

Unfortunately, what you are experiencing is NOT normal, albeit possibly expected, given the age of the sensors.

The light should not come on at all. That it is initially means the LTPWS is not receiving a signal from one or more tire sensors. That it then goes off, implies it finally receives the signal from all wheel sensors. That it comes back on, implies one or more sensors are no longer communicating with the LTPWS control unit (unless your year only has one light, then it might instead mean it has detected, possibly incorrectly, a low tire pressure situation).

Do you have a FSM? If so, review the section which advises how to pull the codes from the LTPWS to determine which tire(s) sensor is not functioning correctly. You could then have that sensor(s) replaced (if you can find it).

If you do not have the FSM, post a reply and I'll dig out mine for our 1994, which may be the same...

 

mine don't work in my 90, and the light stays out

 

When I changed the front tires about 18 months ago the same thing happened and then about 12 months into this saga the light finally would go out and stay out as designed. I'm hoping it's working up to that now--- but it would always be on at engine start until at least 100 yards of driving--- and you say it should not come on initially unless there is a problem?? Then there must be one---I'll try to pull some codes---Thanks

 

Agree with TheAdmiral94 for the TPS. The light on the DIC comes on when you start the car (as should all lights to show they are functioning), then goes out. After driving several miles, or at a speed exceeding 25 mph, if the light comes on and stays on, then you have a tire sensor problem. Have the codes read and you will know which wheel is giving you the problem. Word of caution, the sensors were changed in 1993 by GM. For your vette, you need the sensors for 1989 to 1992. The sensor housing on the metal attachment band is black for 89-92 and beige for 93-96. Each wheel has a different color coded label, green, blue, orange, yellow. They are not interchangeable between wheels and 1993-96 sensors will not work on 1989 to 92, and visa versa. Since they work on the piezoelectric principle, there is no battery in them as in the C5s. If you do find that the sensor is bad and you replace it, make sure that you keep the metal band that attached the bad sensor to the wheel. It is a valuable item that you or someone else may need later. I don't believe that the bad sensor can be repaired, at least I have never heard of it being done. You also may have to purchase the sensor used unless GM has the particular one in stock. Many posts have indicated that the left front tire sensor seems to fail the most. I replaced my right rear and left front sensors and the LTPWS light then functioned properly. You may have to search the CF site or e-bay, or other used corvette parts suppliers to find one. Don't believe anyone that the 1993-96 sensors will work in your 1989-1992. They don't. I have the left front 1989-92 sensor if it is the one you need.

 

Always pay attention to those Colorado boys and girls! Mtnvette spelled it out real good.The tire place screwed up your sensor, let them fix it. Did you tell them? Most shops charge a little extra if they know, and that way there is no question of who pays to replace a damaged one.

 

Thanks guys great info appreciate it!!!!

 

Hi Folks.

About the time I started experiencing a problem (cracking noise) at my right rear wheel (discussed in a separate post), my LTPWS light came on and stayed on after a mile or so from start.

Could these issues be interrelated?

Thanks.

 

Don't wait. Get it checked right away. You don't want a front wheel sensor coming apart at 100mph thru a high speed sweeper, it is more than exciting, I know!
The tire place probably damaged it (easy to do) when they changing the tires, that's how I lost mine.

 

Ok silly question. Were is this sensor located exactly, as my Service LTPWS Light is on as well.
PS I have a 92 with 18" five stars rims on it.

 

Marks on target, The sensor is damaged

 

Just a small point, but the Sensors - 89 to 91 or 92 - can go on any wheel - you need to have one of each color (so whatever comes off a wheel - unless you're removing all of them - should be the color you get). Tire size, tread pattern and wheel determines where the wheels are placed - sensors don't. GM issued a Bulletin correcting the Service Manual (which for the early Years instructs you to dismount the tires if you want to rotate them). Agree that the Codes need to be pulled so that you can find out which one is problematic.

 

If you go over to the zr1netregistry.com site and look in the maintenance section under the "How To" tab you will find a write up on some possible corrective actions to repair the sensor.


Tom

http://www.zr1netregistry.com/ZR1_ltps.htm

 

Well it’s possible the sensors were not put back on when the wheels were remounted (hence the service LTPWS light) or you have one or several bad LTPWS sensors. Normally they ride on the inside of the rim one sensor per wheel (Tire shops are famous for busting these when unmounting the tires) the sensor body is attached to a metal band like a large hose clamp with a counter balance in each wheel. The sensors are color coded and marked for each wheel. The early model years are black bodied sensors 89-91 MYs and the 92-96 MYs are white or cream colored sensors. Both types work on different RF frequencies so you need all of one color to get the system to work right and they are not interchangeable.

 

The sensors are mounted with the head unit 180 deg. from the valve stem, exactly opposite it, on the same side as the stem, the side facing out.