TPMS - 8 PSI Warning

I've seen the sensor output page in the Techstream system and the set pressure is tied to the specific sensor ID and not the position on the car. The TMPS system does not know where the tire is, just what four sensor IDs are associated with it. And each sensor ID has its own set point. So when you rotate tires, you'll need to go through all your steps to have the settings correct again. Sorry. I can confirm from looking at that page though, that your observation of an 8psi offset seems to be correct. My tires were at 48/46 and my trip points showed in the system as 40/38.

As for mixing nitrogen and air, don't worry about it. The air you breathe every day is 78% nitrogen to begin with, so mixing the two will have no effect at all.

 

Nice to know. Thank you!

Marty

 

You pushed me over the edge to order that gauge and the Check-a-Spare valve extender. I now won't have to pull the spare all the way out to check its pressure periodically.

Chek-a-spare, Check-a-spare, tire gauge guard

 

According to the Owners Manual, we have to activate the system. I have not done this because I check my tire pressure regularly and I plan to buy winter tires with their own wheels so I'll mount them once without transferring or installing a set of TPMS sensors in the winter tires. I could just deflate the tires to see if the warning light comes on, but thought of this question while reading this thread.

Has anyone checked their TPMS to see if the dealership activated their system as part of the new car setup and prep procedures? --TK

 

I had a low tire from a puncture a couple of weeks after I bought the car. System worked as advertised. I hadn't done anything to activate the system.

 

I highly doubt that changing from 78% nitrogen (also called air) to close to 100% nitrogen would make a difference. Add this to the fact that your tires are not vacuum pumped before supposedly pure nitrogen is pumped in it. You are probably getting something around 90% nitrogen in the end. 78% or 90% should not make that much of a difference. Air humidity has a greater impact but use of nitrogen doesn’t ensure that the gas (air/nitrogen) moisture is reduced.

IMHO, the nitrogen thing is mostly a hoax, especially when you consider the price you are paying.

 

I have one installed on my spare, and ran it so the end is in the small storage area on the left side of the cargo area, where I keep my Accu-Gage and disposable plastic gloves for pressure checking. I cut a small notch in the underside of the large storage area above the spare so the hose wouldn't get kinked.

 

Great idea. Thanks!:hail:

 

Thanks,PF, Rachael7, and Jay: great info!

 

From the initialization procedure (TSB 0151-09)

The Low Tire Pressure Warning Light will blink
for 1 minute and then remain illuminated until
all the tire pressure warning valves/sensors are​

activated.

If it's not blinking and then lit the dealer activated it, as he should. This bulletin was included with the '10 manual download from another site.

 

Nice write-up pfreeus! I think I'll be setting up our ride in a similar fashion. There was another thread along these lines and it got me thinking; I just haven't acted on it yet; thanks!

 

Fast Shipping! I placed an order with getagauge.com shortly after this post on Friday, and got the items in postal mail today! Great service! :rockon:

 

I am so envious.... Crossing my fingers that the my cable on its way will work with my version of Techstream

 

It's handy to be able to get in there, I have to say. Was not cheap and I wish I had a local club or group I could have shared costs with. But having past the bill-paying stage, it sure is nice to have full access to my own car. Good luck with the cable!

 

I installed mine today, and just ran it to the left side area under the middle of the large storage bin. I was able to drop the bin back in without kinking the hose or needing to cut a notch in it.

My spare was down to about 45 psi when I checked it, though, instead of the 60 psi it should have. I bumped it to 72 or so using my new gauge with the fill valve.

 

mine came on about 20 lbs light. i had mine set at 42 PSI, when light came on, i pulled over immediately and TP was 22 PSI.

 

Are you losing air rapidly from that tire? Based on what I've seen and read, it should only have gone that far low if the time lag (between initial low pressure and onset of warning) allowed the pressure to continue dropping past the trip point.

 

this was in my SPM and happened on way home from dinner last fall. it was a slow leak, that was later determined to be caused from a nail. the nail was pulled, the tire repaired and that same tire is now pushing 42,000 miles. it is OEM equipment.

it leaked rather slowly to the point that i would pump it to 50 PSI every 3-4 days or so. i drove it like that for nearly two weeks before i had a chance to get it fixed. (ya, me lazy)

although the economy sucks, i live in an area with heavy new construction. the recession has slowed the roll down slightly if at all. (across the main road from my development, house building was put on hold for the better part of a year, but they are back in full swing now)
but i have caught a nail 3 times last year. sucks...