My new 20" HRE P43s are consistently reading -4 lbs psi in the passenger rear. This is so even though my very accurate hand gauge says it is 40 lbs. If I reset the TPC program it goes away for a while but then comes back after the car sits for a bit. I assume it reads low once they cool off and the air contracts.

This is bugging the hell out of me. I suppose it could be a bad sensor in the tire. I don't think it is losing air because it has been doing it for a week and the tire is not low at all.

Any ideas?

Pressures sensors are often an issue on larger diameter/smaller sidewall setups. HRE has surely encountered this and could have a quick solution for you

It's not an issue with the wheel. It's an issue with the sensor. Dismount the tire clean off the sensor of any tire mounting lubricant or obstruction and it should return to reading properly. Whomever mounted these should fix it free of charge. If it continues to read improperly you will need a new sensor. Good luck

I disagree with the bad sensor post. My new HREs, 20's 547s, do exactly the same thing. Rears read a little low 4-5# although my handheld gauge reads right on the money. Not losing any air but they BOTH are about the same, -4-5# consistently on the TPMS system. If it were a bad sensor it would only show in one wheel I believe. I havent the foggiest why this is but since I know they are not leaking and show the same for both rears, Ive grown to not care what the TPMS system says anymore allthough it is a slight bit annoying. If all of a sudden one rear read -10#, I would know there is a problem.

To be honest, pressure sensors are a friggin joke anyways. Half the times people are having problems with them and the other half you cant trust em anyways. I'll just take my chances with the old seat of the pants feel when I get a flat.

Yeah. But its that damn red exclamation point that bugs me. I see it and I start looking for check engine lights. I am OCD about stuff like that.

Wow sorry to hear you guys are having trouble. Good luck with HRE's customer service. Keep us posted of the out come.

Barrister,
Call Betim at BBI and have him remove/inspect and re install the sensor. May have been damaged while installing. That is the best first step.
Marc

Is there something in the nav / computer that allows changing of settings for this? Like most I speed read through the manual but I swore I saw something regarding this. Will check.

Just checked the tires after leaving it over night. My handheld gauge says no loss of air. So it must be in the sensor. I have not driven it yet. We'll see if it still reads -4.

Checked the car and the passenger rear is find but now the driver's side rear reads -5!!! This is getting ridiculous.

So, I filled the driver's side rear with a few pounds, made it equal with the passenger side rear (40 lbs in each) and reset the TPC system. Right now it reads properly. I hope it stays that way or I am going to have to take it back to BBI and have them check it out.

I have a question for you guys as well. Does it make much difference if you change the settings in the TPC to either Summer or Winter Tires? And how about the Partial vs Full Load setting. Mine was set for Summer Tires and Full Load. Most importantly, is there a way I can just turn the TPC off? I never look at it and prefer to take the readings with my handheld gauge.

Thanks for all the help.

barrister,

mines is off by ~-4psi. i have stock wheels. i recall reading it in rennlist that the dealer can turn this 'feature' off. check with your local dealer.

btw, nice wheels!

It can be turned off at you dealer using the PIWIS.

Beru instructs the sensors to be installed with the sample holes pointed radially outward from the center axis. When I removed the old sensors and put them on my new wheels some of the old ones were oriented the opposite way so the holes pointed inward which may have caused errors.

Thanks for all the help guys. After I put some air in the tires this morning and reset the system, I have yet to get an error. I am keeping my fingers crossed.

Had same issue with my custom wheels and lower profile tires - filled them with nitrogen and no more false readings since the heat ed gas expands less than air.