danielliez

Hi,
So I have a little problem with my 2008 WRX and wondering if anyone is familiar with this:

Last night I drove up to Truckee (Lake Tahoe area, I'm at an elevation of about 6200 ft). I get all the way over Donner Summit, park my car at a friend's house and leave it for a couple hrs. I come back, get in the car to drive home and my tire pressure monitor light comes on about a 1/2 mile later. I slowly drive about another 1.5 miles to a place where it is safe to pull over/a parking lot with lights and check my tire pressure. They are all good.

I drive the remaining 3-4 miles to get home because I decide that if I really have a flat, I can have my neighbor take me in to town in the morning with my tire to get it patched, and then limp the car to Reno for new tires if necessary.

This morning I check tire pressure and they are all at 32 PSI, but the warning light still comes on. I call one of my buddies that has a WRX and works at a body shop up here and he says that the elevation causes the warning light to come on, and he sees it all the time at his shop.

My concern is that I have been up here countless times since I got the car and this is the first time the light has come on. Also, the one time I actually did have a flat the light never came on!


Has anyone else experienced/heard anything about the effect of high elevation on the TPMS? Another thought I'm having is that maybe my spare is low on air, and the TPMS checks that tire as well? (I've gotta get some stuff out of my trunk and then I plan on checking that one, too).

TIA for any help/ info you guys have!

VRT MBasile

iTrader: (17)

I'd just keep an eye on them and see what the system says when you get back to the bay area. That'll rule out the elevation cause. Or try resetting the system like you do to reset the ECU. Disconnect the negative battery terminal, step on the brake pedal a few times, reconnect battery. Then see if the light comes back on.

If it continues after the system has been reset and you're back in the bay, take it in to the dealership, you're still under warranty.

danielliez

Thanks Matt, I think that's the plan. I talked to my mechanic and he said to just keep an eye on it and then bring it in Monday. If there really is something wrong I will bring it to the dealership and have them fix it for free (yay new car with warranty! ) If I happen to go to Reno today I will drop by the dealership there and have them inspect it.

Uhg... I hate having car problems when I'm at home because I'm not within walking distance of anything so I'm totally stranded. BLEHG!

sleepy_doe807

iTrader: (1)

maybe check spare tire? i know one of my friends had a toyota tacoma (i know different manufacturer) with the same symptoms and it was his spare.

danielliez

Yeah, I thought of that because my mom's car has that... but she has a full-sized spare and I have a doughnut. Do they put TPMS on doughnuts? I think that is pretty uncommon, but I can't find any info on it in the manual/online. I did check pressure on spare and it is a little low, but it's not connected to anything so I'm not sure how the system would be monitoring the pressure.

sleepy_doe807

iTrader: (1)

owner's manual p 11-33 recommends increasing pressure 1 psi for each drop in temp by 10*F. their example is 33/32 PSI @ 60F -> 36/35 PSI @ 30F.

i've read that the TPMS sensors in the regular wheels need to be spinning to send a signal to TPMS "brain", but i don't know if the spare even has a sensor.

if that doesn't help, thank goodness for warranties. g/l.

VRT MBasile

iTrader: (17)

No problem, hope it gets straightened out.

1SIKBRU

iTrader: (2)

Don't even worry about ur car, its acting fine. All that happened was it was cold and the air in your tires compressed. Once you drive for a bit the light will go off because the air in the tires will heat up and expand. Happened to me a few times when it gets really cold and my car has sat outside for a while. One remedy for this is keep your tires at 40psi, then even when its cold ur tire pressure will stay around 35.