DangerBoy

I have a 2008 HHR SS with only 62,000 km on it (~40,000 miles). I've had it a couple years now.

Today, for the first time, I put some 16" winter rims and snow tires on it. The 18" rims and summer tires went in the garage. I didn't put any TPMS sensors in the winter rims. (I live in Canada and don't think that's illegal). I was expecting the Tire Pressure warning alert to go up as soon as I started the car up with the new rims on and the rims with the sensors in them away from the car. Nothing happened (No alerts).

I have taken the HHR out for three or four 5 - 10 minute drives since then and got the car up to a speed of over 100 km/hr on one of those drives and still no tire pressure alert. I thought maybe you had to get the car going over a certain speed to get the system to kick in. Not so it seems. If I look at the tire pressures on the DIC, it's still reading the same pressures on all four tires that it was reading just before I took the rims with the sensors off.

What gives? Isn't the car supposed to tell me it's not reading any pressure in any of the tires?

Don't get me wrong, I'm not unhappy about it. When I did have the other rims on the car one of the TPMS sensors would always shut down on a long trip and give me a false alert and false 0 psi reading on that one tire. It always worked fine again after the car was shut off for a few hours or more and restarted. I'll be happy as a clam if that system never figures out I've removed the sensors from the car and never flashes a warning but I'm not sure I'm understanding the usefulness of a TPMS system that doesn't know when one let alone all of the TPMS sensors have been removed from the vehicle.

Has this happened to anyone else? Any theories as to why this is happening?

Silverfox

Answer ...Yes I have, but a slightly different situation.

Last year I had 4 wheels swapped from one HHR to another.
The same thing happened however it took about 30 miles or so for the DIC to go blank and I had to go to the tire dealer and have them both reprogrammed.

Just keep driving and it might do the same thing once it figures things out.

SF

DangerBoy

What do you mean the DIC went blank? Were any of the other readings affected or was it just the TPMS readings that zeroed out?

Silverfox

Just the TPMS went blank with _ in place of numbers.

DangerBoy

That's no problem. I have a contingency plan ready if that happens. I have come up with a new workaround for the TPM system that I believe will allow me to switch back and forth between summer and winter rims without having to get the car to relearn the sensors each time.

A number of people have posted videos where they fool the TPM system by putting the TPMS sensors in a pressurized PVC pipe bomb but that system has a few drawbacks and weaknesses. My proposed solution is quite different. It's also much simpler, more elegant and should be pretty much fool-proof if all goes according to plan. I'm fairly confident everything will go according to plan but I'm not 100% sure. Of course, if the system doesn't change from the way it sits right now then I may not bother to implement the plan...

I will post a YouTube video of my workaround if my plan works and will post a link to that video in this forum right afterwards. Should be interesting...

donbrew

Just remember that TPMS is required safety equipment. Please don't post the sabotage here.

You could just put your summer wheels in the trunk.

If you are going to drive around all winter with dashes, just remember where the wheels came off, put them back the same place. Viola! no relearn.

DangerBoy

According to Transport Canada, "The Tire Pressure Monitoring System (TPMS) is not a manufacturing requirement on new vehicles sold in Canada, or on imported vehicles. Furthermore, there is no federal regulation that prohibits disabling the TPMS system on vehicles, as vehicle use falls under provincial and territorial jurisdictions."

As it is legal to sidestep the TPMS in this country, I think I should be allowed to post a link to video showing my system for sidestepping it (if I make it) as long as I make it clear in my posting that what I do in that video is legal in Canada but probably isn't in the USA and may or may not be legal in other countries so anyone wishing to follow the methods posted there should first check the laws of their country to make sure it's permissible. I will also make a point of stating that right at the beginning of my video so as to avoid giving the appearance of encouraging anyone to break the laws of their country which would not be my intention. My intention would simply be to show people who are curious to see how it can be done in a much simpler and easier way than what has so far been discovered or at least published on YouTube. I hope this is considered reasonable enough for the moderators of this forum to allow my proposed posting to stand if it's posted. It's all hypothetical now because I don't know for sure my plan is going to work as well as I think it will.

DangerBoy

So does this mean the system won't tell me that a tire has gone flat until I've driven 30 miles on it? That doesn't sound too useful if that's what happens. If I take the sensors out of the equation, the system should flash an alert instantly, not after a long period of driving. I can sort of understand why Governments in Canada have been circumspect in evaluating the usefulness of TPM systems before going all in and making it mandatory for vehicles to have them. On the other side of it, I can see why some people think such systems are sometimes useful and good to have. I think I'll just stick to regularly checking my tire pressures and looking at my tires every time I walk up to my vehicle and NOT relying on a potentially flaky system to warn me when a tire gets low in pressure. I get too many false positives with the system in the HHR to put a lot of trust into what the system tells me anyways. I have no experience with systems used in other vehicles or vehicle makes.

donbrew

What about Provincial laws? I don't know. I do know that in my state if safety equipment was installed at the factory it must be present and working, the Federal D.O.T. doesn't care once it leaves the factory.

I guess no Canadians got killed in the Ford/Firestone debacle, which is the reason for TPMS, somebody said "there ought to be a law".

We cannot condone dangerous modifications for liability reasons. When the time comes the Admin will have the final say (he is the lawyer).

I was very respectful in my request, it was not meant to rile you up.

If your system is not functioning properly fix it. Could it be 9 year old batteries? Millions of other people don't have a problem with their TPMS. I had 2 HHRs, the only problem I ever had was with RF interference causing the RR to lose connection occasionally on the 2008 (I had a laptop and 2 cellphones on the passenger seat). The pressures were always within .5 psi of a gauge.

This subject has been discussed many times. There are plenty of car hacking sites that will satisfy your urge to publish.

Oldblue

According to my sources here in Ontario, Canada
Any safety equipment or systems installed at the factory must be in full working condition and not be tampered with or altered.
That's from my mechanic, he stated he would fail the vehicle during a safety inspection if the TPMS is not functional due to missing parts such as sensors.