Tire Pressure Monitor Issue

[Ashi]

I leased a 2021 Explorer with the 202A package. Its my second Explorer and I love it. I as well have the wiper issue and the sloshing sound when the tank is full. I have a question..... I find the tire pressure monitor keeps changing numbers from the minute I start to drive. Once it went down below the recommended cold pressure. Are those numbers real? Shouldn’t it be at a constant number and not change?

 

[Cincykz]

Typically those sensors will display their remembered psi from when you shut down, probably "hot" if you had been driving. Then as the new readings come in, they will display as a drop, and should climb back to their hot pressure as you drive and heat up the tires. If your cold to hot spread is 5lbs or less, I'd say all is well.

 

[quickfix]

Mine starts off at the cold preset...33psi, and then rises as shown on the dash while I drive at highway speed. They'll go up to around 35-37psi and remain there until I'm done driving. When I park the car the psi will remain up for a few hours, and can be monitored on the FordPass app on my phone.

Later in the evening it will have reduced to the cold preset...33psi, again as monitored on my FordPass app and the dash. The psi in the morning will be as it should be (indicated on the B pillar placard) , both on my phone and on the dash.
I still manually check cold pressures every few days and adjust that preset as required...just because that's the way I've always done it. Old habits.

 

[1sttimeexplorerowner]

Cold air pressure readings are different than hot. That's why they recommend checking your air when the car hasn't been driven for a bit of time. Don't check your air pressures following a drive.

Also always have an ACTUAL tire pressure gauge. Most in board monitoring systems aren't as accurate and could be off by as much as 3-4 PSI. Could be from worn TPMS or just an inaccurate reading from the car's computer. It varies from car to car.

The last time i checked my tire pressures on the EX, it was off by 1 PSI.

I use this. Not the same brand but the same type.

https://www.amazon.com/dp/B00XPL88NC/?tag=serious-20

Whenever i add or check, i use that type of gauge. I hardly ever use the inboard computer gauge because of the inaccuracy.

 

[peterk9]

My readings seem to be fairly accurate. I check the TPMS readout after leaving the dealer when I've had the winter/all-season tires switched. 32 psi front, 38 psi read. IIRC. Too cold to go out and check the door sticker.

Peter

 

[Ashi]

My readings seem to be fairly accurate. I check the TPMS readout after leaving the dealer when I've had the winter/all-season tires switched. 32 psi front, 38 psi read. IIRC. Too cold to go out and check the door sticker.

Peter

Theres one sensor that is always off by 3-4 lbs. When I take a manual reading with a gauge it shows the same thing. I add air and a few days later it’s back down again. Went to check to see if my tire had a slow leak and it did not.can it be the sensor.

 

[peterk9]

Theres one sensor that is always off by 3-4 lbs. When I take a manual reading with a gauge it shows the same thing. I add air and a few days later it’s back down again. Went to check to see if my tire had a slow leak and it did not.can it be the sensor.

If the tire gauge and the sensor are both giving you the same reading, I doubt that it could be a faulty sensor. After you bring the tire back up to the correct pressure, does the sensor also show the correct PSI? If you let it go, will the PSI continue to reduce beyond the 3-4 lbs? If so, I would suspect a slow leak somewhere.

Peter

 

[1sttimeexplorerowner]

The TPMS reading in the gauge cluster is off by 1PSI. At least my car is.

Checked via vaccuum analog gauge, 33PSI. Looked at the gauge cluster, it read 34.

TPMS in my corvette is accurate.

Not sure if it's the actual sensor or the communication between it and the car's computer that there is a fault or misreading.