dmuellenberg

Replaced all 4 TMPS units last fall. Took the Z06 out of storage the other day and the right rear TPMS reads 0 (the other 3 are working correctly). I manually checked the air pressure and it read 32 psi. Drove it for several miles thinking it needed to reset, but still reads 0. Of course I also get the message I have a flat tire and that max speed is 55 mph. If the unit was defective, I would think it would read XX and not 0. Anyone have any idea why it isn't showing the correct psi?

RamAir972003

Its normal lazy sensors will get up in psi after driving it and heating up tires...normal dont panic good day ....

MTPZ06

Sounds like a suspect sensor, but driving for a bit should wake it up. If you have a programming tool, you could try resetting it that way as well.

HOXXOH

Don't panic. It just has a weaker signal and will most likely reset itself after a few miles and ignition cycles. I have one acting like that for the last 60K miles. It may go 2K without a problem or twice in 50 miles. Sometimes it clears itself in the first couple of miles and other times I can go 100 miles before it resets.

I have 142K on the car, but won't bother changing sensors until one of the other 3 fail.

LMB-Z

I have a couple that does it from time to time. They usually reset themselves after a few miles. Not worth it to me to spend $60+ for sensors plus having to break tire down and install.

Must_Have_Z

If you have a Discount Tire shop nearby, just take it there. They will reset them all for free.

HOXXOH

That only corrects a location problem. The OP's sensor already knows the correct location.

Bill Dearborn

It sounds like you have a bad sensor. Programming does nothing to the sensors. It only identifies to the car which sensor ID code shows up at each corner of the car. Once that is done the car remembers the ID code for that location. However, a programming error from last year could be the cause your problem. If somebody programmed the sensors to the wrong location by not following the proper sequence you could have a 0 pressure tire located some place else on the car. If you have run flats you wouldn't be able to tell without checking the pressure of each tire with a gauge.

If the sensor battery failed completely you would see XX on the screen because the car wouldn't see the sensor ID code being broadcast. The fact that the car is displaying a 0 pressure reading indicates the car sees the sensor ID code and that the sensor is sending a 0 pressure signal. Although the sensors were new last year there are many things that can happen to them over a period of a few months. Moisture inside the tire can corrode the pressure sensing element and keep it from working properly.

Bill

dmuellenberg

I probably should have included more info on my original post, sorry for not doing that. Here are a few more details. When I took it out of storage, the right rear tire was flat. I filled it up with air and the TMPS did work correctly at that point, but there was a leak in the tire so I took it to Discount Tire. They said the sidewall was ruined so I needed to replace the tire. After they put the new tire on, the TPMS showed 0 and so far has not reset to read the correct psi. So The TPMS was working earlier but not since Discount Tire put the new tire on.

HOXXOH

The mere fact that the display shows a "0", means the sensor responded to a request from the RCDLR. If there was no response, the display would show "XX". You may also get a response on the DIC that reads "(XX) TIRE FLAT SPEED 55, REDUCE HANDLING", where the (XX) will show the location.

Another DIC warning would be "SERVICE TIRE MONITOR". Then there is the "LOW TIRE PRESSURE (XX)" warning that occurs when the pressure drops to 24 or less and the "HIGH TIRE PRESSURE (XX)" warning when the pressure is above 42. The exact pressure will be displayed on the DIC when requested by the driver's control panel button.

The "0" could be the last remaining information transmitted until there have been at least one more ignition cycle and a speed of 25 mph (or more) for a continuous period of at least 2 minutes. The RCDLR retains the DTC for 100 error-free ignition cycles, even though you can manually clear the message on the DIC screen, or the sensor starts sending valid information. All the tire pressure information stored in the DCDLR is lost upon a loss of power. So maybe disconnecting the car battery for a few minutes would be the first thing to try and follow that with the driving speed/time sequence.

It's also possible that the tire store damaged the sensor when changing the tire.

Try driving the car over 25 mph for 2+ minutes on 3 separate occasions with at least an hour of shut down in between. If you still get the "0", go back to Discount Tire and tell them they probably damaged the sensor, since it hasn't worked after the tire change.

Dan_the_C5_Man

I've had sensors damaged before, it can happen if the valve stem seal is pulled while the tire is full (sudden rush of air), also possible during mounting (if they had issues seating the bead).

I will say the TPMS on these cars can be finicky - I've seen sensors (new and old) randomly drop in and out for seemingly no good reason.

rabrooks

Anything below 21 psi shows "0" pressure. add a little pressure and they'll register. After pressure, sometimes it takes a 5 min trip for them to pick up the new pressure

dmuellenberg

Not the issue. Tire has 32 psi and I've driven it about 50 miles now and still shows 0. I've gone through shutdown/startup several times now. Think the sensor is bad.

dmuellenberg

Update: finally got around to disconnecting the battery to see if that would help, but it continues to show 0. What it did do, and I find it odd, is that the low tire pressure light no longer shows on the dash and I no longer see the Right Rear Tire Flat message on the DIC every time I start the car. Have an appointment on Tuesday to have the shop that installed the sensors take a look at it.

HOXXOH

Don't know why you find it odd. Back on post #10, I said " All the tire pressure information stored in the DCDLR is lost upon a loss of power."

If you've driven the car the required time and speed since the battery disconnect and the DIC still shows 0, then the sensor is bad and probably was damaged during the recent tire installation at Discount Tire.

dmuellenberg

I understand that the readings are lost on disconnect of power. I find it odd because I thought after disconnecting the battery and driving it for the required time (which I'm sure I have by now), if the TPMS still reads 0, why would the computer think a 0 reading would be ok? If it continues to get a 0 reading, shouldn't it still notify me that the tire is flat rather than think everything is ok?

HOXXOH

I don't know how the computer is programmed, but my guess would be that a displayed 0 is the default character that indicates there is communication, but no psi value returned, aka a null value.
If there is no communication, the display shows XX.

Because you said the sensor functioned properly before the tire needed to be replaced and now can still communicate, but lacks the ability to transmit pressure data, the assumption is that damage occurred at the time of the tire change at Discount Tire. The shop that did the original sensor install last year didn't create the problem.

dmuellenberg

If there is no communication then it should display XX and I should get an error message to service the TPMS. Since it is displaying 0, then there is communication. The computer only knows that it is receiving a 0 reading from the sensor and it doesn't know if it because there really is no tire pressure or if the sensor is not working properly. So even after disconnecting/reconnecting the battery I would expect it to notify me that the tire is flat because of the 0 reading, instead of no warning at all.

FYI - I never claimed that the shop that installed the sensors created the problem. I just don't trust Discount Tire to be able to solve the issue or even take responsibility for it. Discount Tire couldn't even get the bead on the tire to seal properly and told me they did all they could and didn't know what else to do. I trust the shop that installed the sensors so that is why I am taking it back to them for resolution. I won't trust Discount Tire with my custom wheels again.

HOXXOH

Sorry you didn't understand what I wrote when I tried to help you. Of course, when you didn't tell the whole story, it makes it difficult for anyone to help. Your reading comprehension leaves a bit to be desired, so try re-reading my previous 2 posts and your responses. What you expect the car to tell you, is obviously not what you want to hear.

dmuellenberg

Not sure why you think I didn't understand what you wrote and you think my reading comprehension leaves a bit to be desired. I'm curious though what you think it is that I expect the car to tell me and exactly what I want to hear? Maybe it's your reading comprehension that is questionable. Your complaint that I didn't tell the whole story doesn't hold water since you did know the whole story prior to your detailed response.

I'll tell you what I expect. I expect that the car should give me a warning that either I have flat tire or that the TPMS needs servicing, even after disconnecting the battery. I had the battery out of the car all winter and when I put it back in it told me that I had a flat tire. So why doesn't it do it now? A 0 reading should give some type of warning message regardless. So if I have a low fuel warning and I disconnect the battery, will it no longer show the low fuel warning after connecting the battery? I expect the car to still give me the low fuel warning just as I expect it to show a low tire warning. According to you, it sounds like that is too much for me to expect.