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Has been sitting for a while while the Monsoon season passes here in south FL. Took out this morning, low tire pressure light came on. Running 38# in rear, 36# in front, GY F-1 -GSD-3's.
Checked pressure, all OK except RF. Lost 5#. Brought back up to 36#, light went out, stayed out. Nice surprise !
My question: My 89 had the same system, and it went south long time ago. This 90 Z, 15K miles, possible the transmitters still working after all this time?
I was going to post a question about the light, but tx working, made my day.
Boatman
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16-'19, '21-'22-'23-'24
Hi Vince, The owners manual says that the sensors may give a LTPW light if the car sat a long time. The inductive battery needs to move to generate voltage to transmitt. If the "reciever box" doesn't "see" the signal it lights the warning light for low air preasure. The book further states after driving a bit the charge builds back up and the signial is now sent & the light should go out on it's own. Mine did that during the winter, when the car sat for weeks on end. I would drive it and the light would go out after about 5 miles. I think, but am not sure, the trigger point is 25 PSI or less for the low tire preasure light to come on. I know it's in the owner's manual, not sure which one though.
Last I checked GM was back ordered on the old style sensors.
Tom - Does this mean that the sensor's are still working after 15 years?
The original owner I bought this Z from, kept it up to date, and if it just hiccuped, it was to the dealer, pronto. I have all receipts, but none showing sensor replacement or maintenance. I will talk to him in the future to see if he had any replaced.
It sat for about 10 days before I took it out Sunday morning. Your theory could be correct, but I had to put about 5 or 6# in the RF tire, then the light went out and stayed out.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16-'19, '21-'22-'23-'24
Hi Vince, Yes it is possible that the original sensors could be still working, mine are. There is a series of "how to's" at ZR1net on sensor repair & how they work. They have a capacitor to store volts generated by an inductive generator. Like those flashlights that you shake & they don't need batteries. The ones on TV. Anyway that is how the sensor generates volts. If it sits too long it goes dead until the tire rotates & the capacitor stores it up again. Tom
[QUOTE=tomtom72]Hi Vince, Yes it is possible that the original sensors could be still working, mine are. There is a series of "how to's" at ZR1net on sensor repair & how they work. They have a capacitor to store volts generated by an inductive generator. Like those flashlights that you shake & they don't need batteries. The ones on TV. Anyway that is how the sensor generates volts. If it sits too long it goes dead until the tire rotates & the capacitor stores it up again.
Good enough, I will fly with that. Thanks Tom.
Vince
Hobe Sound, FL
Btw, I found that it will set the light if the pressure's too high.....when I drove mine down from Colorado, it triggered. I left 6500ft, 25 degree weather at my friend's near the mountains with 34 psi ....by the time I got to Cruces, it was 75 degrees and with the lower altitude, higher temp, driving all day, etc, the pressure was well over 40. Dropping them to 35 turned the light off.
Btw, I found that it will set the light if the pressure's too high.....when I drove mine down from Colorado, it triggered. I left 6500ft, 25 degree weather at my friend's near the mountains with 34 psi ....by the time I got to Cruces, it was 75 degrees and with the lower altitude, higher temp, driving all day, etc, the pressure was well over 40. Dropping them to 35 turned the light off.
Tom - Does this mean that the sensor's are still working after 15 years?
The original owner I bought this Z from, kept it up to date, and if it just hiccuped, it was to the dealer, pronto. I have all receipts, but none showing sensor replacement or maintenance. I will talk to him in the future to see if he had any replaced.
It sat for about 10 days before I took it out Sunday morning. Your theory could be correct, but I had to put about 5 or 6# in the RF tire, then the light went out and stayed out.
Thanks for info,
Vince
Vince
Vince,
I'd like to cover a few facts that might help.
1. There are two lights on the DIC associated with the tire pressure system. One actually says Low Tire Pressure (or something very similar) the other light says "LTPWS". The first light is self explanatory. The second light indicates there is a problem with the system itself. Usually it means a tire is late to report in. In reading your #1 post I'd say your RF tire was not low enough to trigger an actual low pressure light. You may have had a tire slow to report in. The older these cars get the more likely this is to happen. See this write up for details: http://www.zr1netregistry.com/Inform...Revisited.aspx
2. There is no such thing as a peizo battery. It's a peizo charge pump and it drains a few minutes after parking. (not a big deal just technically incorrect)
3. The circuit has no over pressure warning capability, only low pressure (25psi). To assume this could be very dangerous.
The light that kicked on was the LTPWS.......it came on after driving all day, but didn't show up all weekend when I was driving the car around.
I checked the pressure. The highest was over 45psi. The light was on after several start up/shut down cylces. I lowered the pressure and the light went out. I'm sure just a dumb luck coincidence, but a convincing one.
Not sharp shooting at all, but where did you get your tech info on the LTPWS? I'm just curious more than anything. The old system is quite a bit different than the newer systems that can actually give you a specific readout of pressure for each tire and I'm curious what it's actually reporting.....just a simple too low or good switch, or a more sophisticated signal like a modern system.
The light that kicked on was the LTPWS.......it came on after driving all day, but didn't show up all weekend when I was driving the car around.
I checked the pressure. The highest was over 45psi. The light was on after several start up/shut down cylces. I lowered the pressure and the light went out. I'm sure just a dumb luck coincidence, but a convincing one.
Not sharp shooting at all, but where did you get your tech info on the LTPWS? I'm just curious more than anything. The old system is quite a bit different than the newer systems that can actually give you a specific readout of pressure for each tire and I'm curious what it's actually reporting.....just a simple too low or good switch, or a more sophisticated signal like a modern system.
Chris
Among other systems in the ZR-1 I've performed a detailed circuit analysis of the LTPWS system. I've documented the most common failures and the remedies. I posted much but not all of my analysis and findings. When the web hosting changed a few years back much of the detail and accuracy of what is now posted was lost in the move (I just noticed this) Given time later I may go back in and fix the postings.
Yes, as one would expect, the newer systems have changed. They can in fact report actual pressures and the system then decides what action to take.(failure thresholds vary from mfg to mfg) It should be remembered that as a result of the innovation introduced by the early models (and their success) that the feds made tire pressure warning systems required in all cars as of 2008.
The current systems are battery powered and under normal use will last 10yrs. I think the peizo charge pump is superior in this regard. It never requires servicing.
As for the LTPWS light being set. You may have passed by some similar vintage car with transmitters at the same freq as you car OR more likely when it came time for the tires to check in to the LTPWS you passed near a fairly high powered radio frequency tower/transmitter. This could swamp the receiver front end of the LTPWS. The system would respond with setting the light on since it things one of the four transmitters has failed. Keep an eye on it. If it should set again find some road with those ribs along the sides (designed to wake up a sleeping driver). Run one side of the car on these for about 5-10 seconds. If the light stays on try the other side of the car. If the light goes out (one side or the other) you've located which side has a transmitter that is beginning to fail. Usually it is the weighted end of the peizo cell that is starting to stick. It can be filed down or removed and re-soldered to fix this.
FWIW I've seen my LTPWS set more than once when attending events with other ZR-1s in attendance. These transmitters interfere with each other like that.
Hello guys. I am new here. Just got my new 2016 Stongray Z051 yesterday. I have a question regarding the vehicle diagnostic from the Onstar app. It is showing my rear tire pressure is low and my oil life is 17%. Told my dealer and they top up the pressure and changed the oil. But the app message is still the same. How can I reset it?
Final question is do I have to do an oil change at 500 miles?
Thanks in advance. Hope to learn a lot more from you guys ��
Toshibamouse60...There might be some guys here familiar with the C7 that could help you out, but you posted this in the C4 ZR-1 section. You might get a quicker response if you post it in the C7 General section.
Hello guys, I bought a new Z051 last year and only had under 3000 miles to-date. I noticed driver side rear tire is losing pressure slowly and had it charged back to 32 psi. After couple days it will drop to 24 per indicator. Looks like the tire may have a nail? If so can I bring it to my local tire shop or I have to go back to the dealership? Appreciate any advice.
06-05-2005, 12:00 PM
Low Tire Pressure Display
Good enough, I will fly with that. Thanks Tom.
