Subaru Ascent Forum banner
1 - 7 of 7 Posts

·
Registered
Joined
·
35 Posts
Discussion Starter · #1 ·
Temps dropped this week in the mid-Atlantic and like clockwork I had tire pressure lights popping off on my cars. No big deal - manually checked pressure and topped everything off at recommended levels. But the warning light in my Ascent continues to illuminate (although the diagnostics in the menu indicate all tire pressures are at or above factory recommendations).

Anyone have any advice on this? Owner's Manual says the light will reset - how long will that take?
 

·
Super Moderator
Joined
·
2,419 Posts
Did you check the spare tire? I’m not even 100% sure it has a tpms sensor
They do reset automatically so that would’ve happened already if they’re all reading in-spec
 

·
Registered
Joined
·
35 Posts
Discussion Starter · #3 ·
Good point - although the spare does not show up in the diagnostics menu on the dash. I've noticed that every time I drive a new tire drops the yellow warning....had four, then three, then two, now down to one. I get the sense that the reset process will take a few days/trips to cycle through but that does seem odd to me.
 

·
Registered
Joined
·
35 Posts
Discussion Starter · #4 ·
So...some operator error here (or perhaps equipment error). There appears to be a discrepancy between my tire gauge, inflator gauge and the TPMS readings. I put 35 PSI in the tires (per tire gauge and inflator gauge) and received a reading of 220kpa (31.9PSI) from the TPMS. Since it takes a mile or so for the TPMS to take a reading, the cold reading could be as low as 210kpa (30.4PSI).

Do I trust the old school analog tool that I bought for $3 or take the TPMS reading as correct?
 

·
Registered
Joined
·
4 Posts
Temps dropped this week in the mid-Atlantic and like clockwork I had tire pressure lights popping off on my cars. No big deal - manually checked pressure and topped everything off at recommended levels. But the warning light in my Ascent continues to illuminate (although the diagnostics in the menu indicate all tire pressures are at or above factory recommendations).

Anyone have any advice on this? Owner's Manual says the light will reset - how long will that take?
I have the same issue. It's definitely not the spare because it continues to highlight the tire that dropped to 26, even though it reads 30 now.

I read that if you inflate them to at least 35psi and drive, the first reading will turn the warning light off. Then you can reduce the pressure back to 33.

It's a bug with Subaru's software.
 

·
Registered
2020 Ascent Touring
Joined
·
1,108 Posts
210kpa (30.4PSI).

Do I trust the old school analog tool that I bought for $3 or take the TPMS reading as correct?
Do not expect accuracy from a $3 stick style pressure gauge. Expect to spend $25 or more for an ANSI spec rated guage. My digital guage is accurate to .2% psi and the Ascent tpms reads 1lb light compared to the guage.

Everything affects tire pressures including one side of the car being in sunlight vs the other side being in the shade. Here in Florida, the sunny side pressure can be 2lbs higher and it will reverse when traveling the other direction.
 
1 - 7 of 7 Posts
Top