The last C7 Z06 I bought had rash all over the rims that I spent great efforts to touch up. I'm pretty sure it was from the last tire install. A small amount is actually pretty common unfortunately. Installers don't use the rubber coated tire arms and aren't careful. Gorilla method.

 

I assume you meant "rubber coated tire irons" but the tire iron should never touch the rims if the installer uses the equipment correctly. Almost all tire changers these days are "touchless" machines. There should be no contact between the face of the rim and any part of the tire changer or tire iron as long as the tire monkey does not screw up the job. Any marks on the wheel means the job was botched and this should never be acceptable. Low profile and stiff run flat tires are hard to do - but still not a reason (or excuse) to damage anything.

 

Agree with all that. The problem is the tire monkeys. They are everywhere. That's why you do it yourself.

 

OM Freaking G. I tested the new TPMS, even while driving 3 times. The indications were just fine. Today the front two pressure indications switched AGAIN. WTF! My head totally exploded.

 

For LED side marker lights, Oracle brand is known to not interfere with TPMS. I have had them for over a year with no problems. Just adding for reference.

 

I will try disconnecting both side marker lights and see. I will put more foil tape on them and see if this blocks the signal.

 

It would be a good idea to disconnect the side markers for a while to prove that they are actually the source of the problem. The reason some LED parts cause EMI interference is that they use a cheap, switching DC to DC converter to lower the 12VDC car power to a low voltage needed for the LEDs. Those converters use fast switching to keep power dissipation low (so they don't have to use heat sinks) which generates EMI noise. They are acting like a jammer for your TPMS signals. Foil shielding may not be able to prevent the noise from getting out since it can also travel through the wires that connect the side markers. So for a complete shielding system, you would probably need ferrite bead chokes on the wires as close to the source of noise as possible plus any foil shielding needs to be connected to the cars ground using the shortest path possible.

I have done EMI interference mitigation on avionics electronics and I can tell you it can be very difficult to fix interference. The best way to fix it (which you probably do not have a way to do) is reduce the source of the EMI through slowing the switching speed of the converter or changing the switching frequency of the converter. You can also eliminate the switching converter by replacing it with a linear voltage regulator if the current required by the LEDs is low. The last approach generates heat in proportion to the amount of current being used, so a heat sink becomes necessary if the current is more than about 100 milliamps.

One other possibility is that if you have aftermarket wheels, they may be reducing the TPMS signals through blocking thus making the system more susceptible to EMI jamming. Supposedly, the stock wheels are optimized to work with TPMS sensors where aftermarket wheels may not be.

 

It's interesting that nobody else has had this specific issue. The only reason I figured it out, is that I had a tire that was losing air, this made one tire pressure different that the other. If I always kept the pressure the same I wouldn't have known the difference. I have never heard of different wheels causing this issue. In fact I have never heard of this specific issue anywhere.

 

747 = 18 wheelers?

If your TPMS problem goes away after disconnecting (or putting back the GM lights) I would abandon trying to make it work. Life is short, why devil yourself? What makes an LED, or darkened side marker accomplish anyway? I don't subscribe to mods that do not improve the performance in a meaningful way. Appearance mods loose their importance, desirability after a few months.

 

If you do a little searching, you will find that there are many people that have the problem of LED side markers interfering with TPMS. Usually they just get no pressure shown. In your case, enough signal is getting through that you still have pressures shown but the tires are swapped. So the TPMS system determines tire location on the car based on signal strength it gets from each sensor. I would assume that the interference is causing one of the front TPMS signals to get knocked down by enough that the car thinks it is farther away than it really is, thus the TPMS system swaps the indications on your DIC.

 

I have two reasons for the lights on my car. I do like black on yellow look, but also, some of the lights and reflectors were useless for helping other people see you coming. The side lights are now much brighter, the car will show up much better at night and in the day. I also turned my rear reflectors into brake lights, they make the rear much more visible when I am stopping.

 

https://www.corvetteforum.com/forums...pms-issue.html

https://www.corvetteforum.com/forums...demarkers.html

 

Yes, I have heard of aftermarket side marker lights making the tire pressure indication quit, but I have never heard of anybody having the indications switch around. I am looking at another possible reason. I park my car, with the front within inches of a metal shelving unit, at the same level as the front bumper. But after I installed the foil shielding on the back of the units, it's getting better. I drove yesterday, it was fine, parked in the garage and checked this morning, still good.

 

OK, I am done. I drove it yesterday, all was good. I set all of the tire pressures to 31 lbs. If it switches again, I wont know the difference. If a tire loses air I will still get a warning. Finished.

 

Good news. Your foil tape shielding did the trick. I would drop the RF and LR to 30 (cold) just to be able to monitor the situation.

 

I think you might be missing the OPs point. The shielding did not do the trick. He is giving up and letting the tire pressure indications switch if they want to. He will still know if a tire is low, but if both pressures are the same, he just won't know if the readings switch sides. At least, that is what I got from his statement.....

 

I didn't miss the OP's point, you did. Read his last 2 posts.

He had quite an ordeal with his scratched wheel, incorrectly installed TPMS sensor and aftermarket LED lights. He might have drawn the wrong conclusion after 'swapping' the front tires. The relearning process takes time based on several factors, it's not instantaneous. He mentioned 'additional' shielding in the back.

 

EMI/EMC testing is brutal at all the OEMs. The circuitry most modules have to pass like Radiated Emissions is stunning. Bulk Caps, Inductors, etc... Its all about "cleaning up signals"

There is so much noise and interference within cars its amazing. I've noticed things like Bluetooth or cell service can get worse in some cars depending on how my phone is in my pocket (it's on the right side so when I drive its against the center tunnel in all cars).