Tire Pressure Monitoring System aka TPMS

Cody Fousnough

Cody Fousnough

Active member
We have this in our 2021 Dodge Durango GT. We bought new Goodyear Wrangler All-Terrain Adventure tires for it this last Saturday. The tires that were on it, were the original ones for when it was first sold in 2021. Descent tread depth, but some cracking long the tread, due to the high summer heat here. We had new TPMS pressure stems put in. Believe it or not, the max pressure on each tire, listed on the tire, is 51 PSI. When installed, 35 PSI were put into each. What's sort of puzzling is, the driver's side door states "33 PSI in front and 36 PSI in rear". I checked the onboard computer (TPMS) and it states there is 40 PSI pounds in each.

Apparently our TPMS needs to be recalculated? These are new Monitoring Stems.

Any ideas why the TPMS is reading differently than what a tire gauge says? As for myself, I want both the TPMS and the actual tire pressure to match.
 
Do you have the manual for your Durango? My car's manual explains how to recalibrate the TPMS. If you don't have the manual, check Youtube or a Dodge owner forum for help.
 
I've read a few forums where folks have asked for recommendations on a Tier 1 tire gauge, and most folks say there it no such thing. General consensus is that if you try 5 tire gauges (no matter how pricey), you'll get 5 different readings. I have no idea what the accuracy challenge is. It surprises me. (Now that I type this, I might play with the 3 or 4 gauges I own to see how close they are to each other.) I guess my point is that gauges are not accurate, so don't start worrying based on what a random tire gauge says. (You didn't say if you checked the pressure yourself or how you know what they were initially inflated to.)

I also recently read that each tire's pressure sender can be calibrated on some model cars, and I assume they get calibrated to the pressure indicated by the gauge a given mechanic happens to have in his pocket. It might be worth asking if they calibrated the new stems when they put them in, Cody, or if there's a free follow-up to recalibrate them. Reading high makes sense in the heat, just as reading low makes sense in the cold. You should check the tires first thing in the morning, before you drive on them and before the sun warms them up.

By coincidence, my TMPS light just went on last week. For as high-end as my car is, the TPMS is just a dash light that tells me one (or more) of the tires is/are low. It usually goes off at least once in the cold weather (when the pressure is low.) I forget what the Max pressure is for the tires (I think it's above 40psi), but everything I read says to go by the pressure stated on that door sticker. My sticker says 35psi all the way around. Three of my tires were at 32psi (according to my gauge), and the 4th was at 30psi.
 
I talked to the Manager this morning. He told me that, unless I'm pulling something pretty heavy, the tires should never be at maximum (51) PSI. 35 PSI is the normal air pressure for the tires. As for the TPMS, he told me, next time you are in our area, stop by and I'll check the computer against what the actual tire pressure of each tire is. He has the equipment to recalibrate the computer to match the actual pressure.
 
The system used varies by vehicle make and model.

Some use a battery-powered pressure sender mounted inside the wheel, typically as part of a valve-stem assembly. Once the battery runs down to a point where the transmitted radio signal can't be received it is "time to buy more" as well as tire remounting/balancing labor even if the tire itself is in good shape.

My 2018 Civic uses a system based on wheel-speed sensors used for ABS and such. After adjusting tire pressure (adding air) you must drive a number of miles while in "calibration mode" to capture current parameters. No big deal, and no batteries (and whole units) to replace.

Other models with sensor/senders inside tires offer "tire fill assist" mode, where the car chirps the car horn when you reach the proper pressure while filling.
 
Jacob Petersheim said:
The system used varies by vehicle make and model.

Some use a battery-powered pressure sender mounted inside the wheel, typically as part of a valve-stem assembly. Once the battery runs down to a point where the transmitted radio signal can't be received it is "time to buy more" as well as tire remounting/balancing labor even if the tire itself is in good shape.

My 2018 Civic uses a system based on wheel-speed sensors used for ABS and such. After adjusting tire pressure (adding air) you must drive a number of miles while in "calibration mode" to capture current parameters. No big deal, and no batteries (and whole units) to replace.

Other models with sensor/senders inside tires offer "tire fill assist" mode, where the car chirps the car horn when you reach the proper pressure while filling.
Click to expand...
Hey, Jacob! Good to see you again.

Are you saying that the Civic guestimates pressure based upon the car's speed and the # of tire revolutions?
 
John Brunner said:
Hey, Jacob! Good to see you again.

Are you saying that the Civic guestimates pressure based upon the car's speed and the # of tire revolutions?
Click to expand...
I don't know about more recent model years, but my 2018 does.

The theory is that a "flatter" tire has a smaller effective diameter, which means more rotations per mile of travel. Or maybe I have that backwards.o_O
 
Jacob Petersheim said:
The system used varies by vehicle make and model.

Some use a battery-powered pressure sender mounted inside the wheel, typically as part of a valve-stem assembly. Once the battery runs down to a point where the transmitted radio signal can't be received it is "time to buy more" as well as tire remounting/balancing labor even if the tire itself is in good shape.

My 2018 Civic uses a system based on wheel-speed sensors used for ABS and such. After adjusting tire pressure (adding air) you must drive a number of miles while in "calibration mode" to capture current parameters. No big deal, and no batteries (and whole units) to replace.

Other models with sensor/senders inside tires offer "tire fill assist" mode, where the car chirps the car horn when you reach the proper pressure while filling.
Click to expand...
My 2026 CRV has this same system. It's annoying because it doesn't indicate which tire is low, so a person still has to use a pressure gauge to figure out where the problem is. I prefer the systems that show the pressure reading on each tire.
 
Beth Gallagher said:
My 2026 CRV has this same system. It's annoying because it doesn't indicate which tire is low, so a person still has to use a pressure gauge to figure out where the problem is. I prefer the systems that show the pressure reading on each tire.
Click to expand...
The downside though is when the battery dies or sensor goes bad it can be costly to replace. It usually makes sense to do all 4 tires together. Cha-ching.

In the meantime you put up with the warning and go back to manual pressure testing on a regular basis.
 
You must log in or register to reply here.
Back
Top