2013 Cadillac ATS: Tire Pressure Monitor Issue
October 23, 2013
The other afternoon I climb into our long-term 2013 Cadillac ATS. During my short drive home I scroll through the selections on the sedan's instrument cluster and notice it says the right side tire pressures are low. They read as you see in the photo: 31 psi front and 30 psi rear.
At this point I couldn't quote the spec pressure, nor do I know when the car was driven last. Are the tires hot or cold?
What I do know is that 30 psi is probably below spec, but I also know the low pressure warning light is not on and the car feels fine, so I drive home keeping an eye on the readout.
When I get home and open the door I check the jamb sticker. It tells me that the ATS should have 32 psi in its front tires and 35 psi in the rear. It's dark, I'm tired and I'll deal with it in the morning.
The next morning I climb aboard the ATS. It's 6:00 a.m. Still dark. And cold. Now the readout is telling me that the right front is down to 28 psi and the right rear is 29 psi. Still no warning light.
Seems odd. It's dark. I'm tired. I decide to drive the 100 miles to Willow Springs Raceway where I have business unrelated to the ATS. On the drive, the car feels fine and I notice that the pressures only climb a pound or two even after 100 miles on the road.
Five hours later my business is complete. It's time to drive home. But before I do, I borrow a tire gauge from the AMG engineer on site to prep the 35 Mercedes on hand for journalists to lap around the track. The inventory includes four new SLS AMG Black Series.
To my surprise the Caddy's tires are properly inflated; 32 psi front and 35 psi rear. All four are correct according to my German friend's gauge.
So I say to him, "That's odd. The car is telling me the tires are low, but your gauge tells me they are not."
He says in a very stern German accent, "I assure you my gauge is correct. You should drive a Mercedes."
We'll have the Caddy's Tire Pressure Monitoring System checked at its next dealer visit.
Scott Oldham, Editor in Chief @ 17,505 miles