How to Calibrate.......

[GTO 1]

Is it possible to calibrate/adjust the readings of the Tire Pressure Monitors on an '08 Sport?? I don't see it in the owner's manual. I can set the tire pressure at exactly 35 psi and check with TWO digital gauges,,, but DIC will read 31 psi in three tires and 33 psi in one tire. As I drive, the psi will increase 2-3 lbs. as the tires heat up, which is normal. Then. Onstar will send me a warning of low tire pressure as it sees the 3 psi variance from the suggested 35 psi.
So.... how do I get the car to recognize and report the actual (or close) tire pressure???
Thanks guys.. (and gals!)

GTO 1

[cobaltkrazy]

Originally Posted by GTO 1

Is it possible to calibrate/adjust the readings of the Tire Pressure Monitors on an '08 Sport?? I don't see it in the owner's manual. I can set the tire pressure at exactly 35 psi and check with TWO digital gauges,,, but DIC will read 31 psi in three tires and 33 psi in one tire. As I drive, the psi will increase 2-3 lbs. as the tires heat up, which is normal. Then. Onstar will send me a warning of low tire pressure as it sees the 3 psi variance from the suggested 35 psi.
So.... how do I get the car to recognize and report the actual (or close) tire pressure???
Thanks guys.. (and gals!)

GTO 1

one word: Dealership!!!!!

[Red07SSNA]

Try another tire pressure gauge....JK! Tire gauges are not the best "calibrated" tool you can buy. Have it checked out at the dealer, then you'll know if your digital gauges are any good. You'd be surprised at how many different readings you'll get from inexpensive tire pressure gauges!!!!!

[eggalegga]

Originally Posted by GTO 1

Is it possible to calibrate/adjust the readings of the Tire Pressure Monitors on an '08 Sport?? I don't see it in the owner's manual. I can set the tire pressure at exactly 35 psi and check with TWO digital gauges,,, but DIC will read 31 psi in three tires and 33 psi in one tire. As I drive, the psi will increase 2-3 lbs. as the tires heat up, which is normal. Then. Onstar will send me a warning of low tire pressure as it sees the 3 psi variance from the suggested 35 psi.
So.... how do I get the car to recognize and report the actual (or close) tire pressure???
Thanks guys.. (and gals!)

GTO 1

My '08 Sport does the same thing. When I check the tire pressure with two different gauges (one traditional and one digital) they show 35+ psi. But the DIC displays lower. As expected, when the tires are cold, they're 2-3 psi lower until they warm up. I haven't received my monthly OnStar report but it almost always shows the low tire pressure warning.

I just took my car to the dealer to have the TPMS adjusted because after a tire rotation on a previous visit, the tech neglected to reprogram the tires. They adjusted the tire pressure to 32psi. The sticker on the door jam said the Pirelli's should be at 35psi.

Slightly OT, but did you know that you can't put the spare tire in the front if you get a flat? I read this in the owner's manual. If you get a flat front tire, you need to take a tire from the rear, put it in the front then put the spare in the back. Something about bigger brakes or higher braking in the front two wheels. Just FYI.

GTO, love your avatar.

[SPD6IX]

I have the same problem as well.

08 Cobalt LT

Dealer says they can't do anything about it.

[GTO 1]

Originally Posted by eggalegga

My '08 Sport does the same thing. When I check the tire pressure with two different gauges (one traditional and one digital) they show 35+ psi. But the DIC displays lower. As expected, when the tires are cold, they're 2-3 psi lower until they warm up. I haven't received my monthly OnStar report but it almost always shows the low tire pressure warning.

I just took my car to the dealer to have the TPMS adjusted because after a tire rotation on a previous visit, the tech neglected to reprogram the tires. They adjusted the tire pressure to 32psi. The sticker on the door jam said the Pirelli's should be at 35psi.

Slightly OT, but did you know that you can't put the spare tire in the front if you get a flat? I read this in the owner's manual. If you get a flat front tire, you need to take a tire from the rear, put it in the front then put the spare in the back. Something about bigger brakes or higher braking in the front two wheels. Just FYI.

GTO, love your avatar.

Thanks Man!! I did NOT know that about the mini spare on the front. Thanks for that. I know you have to re-acclamate the wheel location to the car computer when U move them, so the car knows where is where, but am still not clear on my (our) problem. Can the dealership "adjust" each TPSM to accurately send to the computer the true tire pressure??? Such as there is 35 psi actual pressure in a tire, can they adjust something so it reports the 35psi to the computer rather than the 31 or 32 or such, like ours is doing now??
Thanks for any info on this...

GTO 1

[eggalegga]

Well my tire pressure warning light came on last night. It was 32 degrees out when I drove home and the light came on. It was on again this morning when I got into my car to drive to work.

The DIC displayed tire pressures as low as 26 - 28 on my tires. I wonder if the tire pressure REALLY drops THAT low during winter months. If that's the case, I'll be having to inflate my tires daily. I still think the DIC isn't displaying the correct psi.

I'm going to call my dealership and talk to someone in the service department.

Just got off the phone with a service guy. He said he had no knowledge of an issue with Cobalts TPMS giving inaccurate readings. I suppose I will have to go once again and put air in my tires. If I fill them up to the Pirelli recommended 35 pounds, and the tire pressure warning comes on again soon, I'm going to press that the service department look into this further.

[Cherry GT]

as for the small spare tire,
you never put one on front of
any front wheel drive car...
different size tires will tear up
the trans..........

digital pressure gauges are very accurate,
unless you bought cheap stuff.