Selectable Tire Pressure Monitoring System (STPMS)

[Scubaz66]

Admin! I did an advance search and couldn't find any post relating to this problem. I did find one post related but it just talked about the UConnect5 glitches. Not sure this problem is related to the UConnect5 system but I wanted to post here as well hoping someone could help lead me to an answer. If I've posted in the wrong group please move it to the correct thread and notify me. Thanks in Advance.

I found this setting when I purchased my new 2022 RAM Big Horn. Its called "Selectable Tire Pressure Monitoring System". As far as I can tell it allows you to set the Tire Pressure to the amount you want to run your tires. I seldom tow a heavy load so I want a smoother ride. I aired my tires to 55psi all the way around and set the Selectable Monitoring System to monitor the pressures at 55psi.

This set up worked for about a year with no problem even with a 3-4 psi threshold given the pressure changes from a cool morning to a hot afternoon and while driving. After about a year I started my truck one morning and the system identified both my rear tires needed air. The cluster on the dash identified both front tires at 51psi but they were not highlighted in "Red" therefore no air needed. Both rear tires showed 52psi and 53psi and were highlighted in "Red" with a warning to air the rear tires to 65psi and the flat tire amber indicator light on dash stayed on.
I took my truck to the dealership and in order to reestablish the settings they had to air up the rear tires to 65psi, drive the truck a few miles until the system reset itself and then reduce the air in the rear tires to 55psi again. This worked for about 3 weeks whereas the system again malfunctioned with the same scenario. All 4 tires indicated low pressure but only the rears needed air.
Another trip to the dealership and again everything was checked and reset. According to the dealer, (I personally know the Maintenance Manager) all four TPMS in each tire were working properly. This tells me the Valve Stems are sending the correct psi for each tire to the receiving module, wherever that module is located. I understand there is a module near the rear of the back seat that relays the information from the tires to the dash cluster. I may be wrong.
After the fourth time to the dealership with this problem (once after a few days and once after a few months), I was told I would have to run the tire pressures to the same psi identified on the label on the door jam. That being 60 front and 65 rear. I disagree based on the fact over time tires wear out and are replaced. My next tires may not be a 10ply tire with a 65psi rating. During my 23 year military career in the transportation business I was taught to never go by this label. It's always recommended to go by the tire pressure identified on the sidewall of the tire. The Tire Manufacturer mandates the correct tire pressures for the tires they manufacture not the automobile builder. Should a tire blow and cause an accident where a death occurs, the insurance companies will go after the manufacturer of the tire before bringing in the automobile manufacturer. I was also told the Selectable function is only used while airing up your tires. You set the PSI amount and when you air up the tires the truck will flash the 4-ways when you have reached the selected amount. Again!! Why have the ability to set pressures different than what is stated on the door frame label if the system doesn't recognize the psi's selected by the consumer?
Which brings me to my question.... Dealer says Chrysler states you have to maintain 60psi front and 65psi rear in order for the TPMS to work properly. If this is indeed the case, why bother with allowing the ability to change these settings in the configuration? Why not just use the same system used in other Chrysler vehicles?
My other question is why is it always the rear tire pressures that cause the system to identify low tire pressure? Shouldn't the front tires also cause the system to identify low tire pressure? I do believe when the government mandated that all auto manufacturers in the United States provide this system of monitoring tire pressures for Safety and Fuel Consumption they required all 4 tires to be monitored properly.
I have a truck still under warranty and a TPMS that fails to function properly.
Anyone else having this problem? I'm thinking it may be a memory problem because it only happens when I park the truck overnight and the ignition is shut down. It never happens while driving down the road. I do know the UConnect5 System in my truck loses memory placement on my music selection constantly or the system forgets what screen it was on when I stop to get gas or run errands.

 

[Jimmy07]

Here’s what you have going:
Your tire pressure thresholds are configured in the BCM for 60psi fronts, and 65psi rears. Nothing can change that configuration except for aftermarket tools, such as AlfaOBD or Jscan.
The low tire alert screen is set to come up when those thresholds fall 20% or below, so that would be at 48psi for your fronts, and 52psi for your rears. As soon as the fronts or rears drop to those respective numbers, you will have to air them all the way up to 60 or 65 before the low tire pressure warning will clear. THEN you can air back down to 55.
So, in your case, your TPMS system was behaving correctly. All 4 tires aired down to 55psi = no alerts or warnings, because they are within 20% of the thresholds.
Rears dropped to 52 = 20% of threshold, hence the alert to air them back up to 65. Fronts never dropped to 48, hence no instruction to fill those back up to 60.

Now onto the selectable tire fill alert system:
This system is not changing the pressure warning thresholds in the configuration. The only purpose of the tire fill alert systems is to alert you via horn honk when you’ve inflated the tires to a desired PSI when it’s active. It has nothing to do with when the low tire pressure warning screen comes up.

 

[Scubaz66]

Here’s what you have going:
Your tire pressure thresholds are configured in the BCM for 60psi fronts, and 65psi rears. Nothing can change that configuration except for aftermarket tools, such as AlfaOBD or Jscan.
The low tire alert screen is set to come up when those thresholds fall 20% or below, so that would be at 48psi for your fronts, and 52psi for your rears. As soon as the fronts or rears drop to those respective numbers, you will have to air them all the way up to 60 or 65 before the low tire pressure warning will clear. THEN you can air back down to 55.
So, in your case, your TPMS system was behaving correctly. All 4 tires aired down to 55psi = no alerts or warnings, because they are within 20% of the thresholds.
Rears dropped to 52 = 20% of threshold, hence the alert to air them back up to 65. Fronts never dropped to 48, hence no instruction to fill those back up to 60.

Now onto the selectable tire fill alert system:
This system is not changing the pressure warning thresholds in the configuration. The only purpose of the tire fill alert systems is to alert you via horn honk when you’ve inflated the tires to a desired PSI when it’s active. It has nothing to do with when the low tire pressure warning screen comes up.

Thanks Jimmy! The 20% threshold makes sense, so its the ambient air temperature during the overnight hours that's causing the system to trigger Low Air Pressure. I'm surprised I was able to go a year without this happening because as we know ambient air pressures change throughout the seasons especially during Winter and Summer months in Ohio.

But why have a selectable tire fill alert system where a customer can set tire pressures alerts lower than the threshold? I went to my truck to see just how low of a psi I could set the Alert System, but when I started the truck I received several messages such as no display for mileage, service trailer break system, service electronic stability control, service antilock brake system, 4 wheel drive temporarily unavailable and auto park disabled. I was also unable to activate the STPMS.

 

[AH64ID]

But why have a selectable tire fill alert system where a customer can set tire pressures alerts lower than the threshold? I went to my truck to see just how low of a psi I could set the Alert System, but when I started the truck I received several messages such as no display for mileage, service trailer break system, service electronic stability control, service antilock brake system, 4 wheel drive temporarily unavailable and auto park disabled. I was also unable to activate the STPMS.

There isn’t a selectable tire fill alert system that allows you to adjust the warning threshold. STFA is for inflating and deflating tires, not the TPMS alert. Two separate things.

As for the rest of your warnings, how old are you batteries?

 

[Jimmy07]

Thanks Jimmy! The 20% threshold makes sense, so its the ambient air temperature during the overnight hours that's causing the system to trigger Low Air Pressure. I'm surprised I was able to go a year without this happening because as we know ambient air pressures change throughout the seasons especially during Winter and Summer months in Ohio.

But why have a selectable tire fill alert system where a customer can set tire pressures alerts lower than the threshold? I went to my truck to see just how low of a psi I could set the Alert System, but when I started the truck I received several messages such as no display for mileage, service trailer break system, service electronic stability control, service antilock brake system, 4 wheel drive temporarily unavailable and auto park disabled. I was also unable to activate the STPMS.

Like mentioned above, STFA doesn’t have anything to do with when the warnings come on. Its sole function is to be a fancy tire gauge that alerts you with a horn honk when you’ve inflated a tire to a desired “selected” pressure. If that selected pressure happens to be below 20% of the placard threshold, the low tire pressure warning screen will still come up.
As for the other warnings you just experienced, that’s something else entirely going on, not related to tire pressures.

 

[Scubaz66]

There isn’t a selectable tire fill alert system that allows you to adjust the warning threshold. STFA is for inflating and deflating tires, not the TPMS alert. Two separate things.

As for the rest of your warnings, how old are you batteries?

Almost 2 years. I'm still under warranty. Just got off the phone with the Service Department and they mentioned the possibility of a circuit drain in the system. I did notice the batteries seem to be weak when I started the system.

UPDATE! Dealership had to replace the battery at 20 months old. According to the Service Advisor this has become a common issue with manufactures because of all the electronics associated with these newer vehicles. When the voltage failed to maintain the required volts to any of the 23 electronic devices the computer identified a failure of said component. This also caused the Check Engine Light to stay on until a new battery was installed and correct voltage supplied to each of the necessary components. I opted for the higher priced alternator when I built my truck.

Has anyone else ran into this problem?

 

[Scubaz66]

Like mentioned above, STFA doesn’t have anything to do with when the warnings come on. Its sole function is to be a fancy tire gauge that alerts you with a horn honk when you’ve inflated a tire to a desired “selected” pressure. If that selected pressure happens to be below 20% of the placard threshold, the low tire pressure warning screen will still come up.
As for the other warnings you just experienced, that’s something else entirely going on, not related to tire pressures.

Again thanks Jimmy! I now understand the difference between the two systems. However, you would think the engineers would not have allowed any settings below the threshold of 60 Front and 65 Rear. Since I can't currently get into my STPMS I'm not sure the lowest setting available. Seems I was able to go as low as 50psi both front/rear maybe lower.

Given consumers utilize these trucks for many different driving conditions, ie normal road conditions while traveling to and from work, pulling heavy trailers and occasionally 4 wheeling, where lower tire pressures give better traction and higher tire pressures for heavy loads, you'd think the engineers could incorporate this necessity within the system. Just a thought! LOL

 

[Poolmonkey]

Again thanks Jimmy! I now understand the difference between the two systems. However, you would think the engineers would not have allowed any settings below the threshold of 60 Front and 65 Rear. Since I can't currently get into my STPMS I'm not sure the lowest setting available. Seems I was able to go as low as 50psi both front/rear maybe lower.

Given consumers utilize these trucks for many different driving conditions, ie normal road conditions while traveling to and from work, pulling heavy trailers and occasionally 4 wheeling, where lower tire pressures give better traction and higher tire pressures for heavy loads, you'd think the engineers could incorporate this necessity within the system. Just a thought! LOL

They put a left arrow button on my steering wheel that works upon startup, easier than maintaining or fixing things.

 

[Scubaz66]

They put a left arrow button on my steering wheel that works upon startup, easier than maintaining or fixing things.

Isn't that the truth!! Unfortunately it doesn't make the Amber Tire Light go out on the dash..... lol

 

[Scubaz66]

Now I understand why my truck arrived from the factory with 90psi in all the tires. Over the almost two years I've owned the truck I can't run with anything less than 60psi front and 65psi rear. Anything below those psi will invoke the TPMS to identify low tire pressure causing the notification cluster to pop up warning of Low Tire Pressure and the amber light to illuminate on the dash. I purchased a damn good Digital Tire Pressure Gauge and use it to check tire pressures when inflating. The Select Tire Pressure Monitoring System or the Valve Stems Chrysler uses to monitor tire pressures are total crap. There is at least a 4-5psi difference between what Chrysler's system states and what my Digital Gauge states. Why even have a Selectable Tire Pressure Monitoring System where the consumer can set the required psi from 15psi to 95psi when inflating tires if the only possible values must be 60psi front/65psi rear? Yes I know I can just put 90psi in all my tires like Chrysler did when they shipped it and the problem will go away however, it will then become a safety issue with overinflated tires. Ram Cares I know you monitor this forum, care to explain what the consumer needs to do to fix this problem? Is it faulty Valve Stems? Faulty TMPS? Software Update? I've had my truck in the shop several times and they will no longer respond. My only alternative is to contact the NHTSA.

 

[Jimmy07]

Now I understand why my truck arrived from the factory with 90psi in all the tires. Over the almost two years I've owned the truck I can't run with anything less than 60psi front and 65psi rear. Anything below those psi will invoke the TPMS to identify low tire pressure causing the notification cluster to pop up warning of Low Tire Pressure and the amber light to illuminate on the dash. I purchased a damn good Digital Tire Pressure Gauge and use it to check tire pressures when inflating. The Select Tire Pressure Monitoring System or the Valve Stems Chrysler uses to monitor tire pressures are total crap. There is at least a 4-5psi difference between what Chrysler's system states and what my Digital Gauge states. Why even have a Selectable Tire Pressure Monitoring System where the consumer can set the required psi from 15psi to 95psi when inflating tires if the only possible values must be 60psi front/65psi rear? Yes I know I can just put 90psi in all my tires like Chrysler did when they shipped it and the problem will go away however, it will then become a safety issue with overinflated tires. Ram Cares I know you monitor this forum, care to explain what the consumer needs to do to fix this problem? Is it faulty Valve Stems? Faulty TMPS? Software Update? I've had my truck in the shop several times and they will no longer respond. My only alternative is to contact the NHTSA.

When you open the front driver door, there’s a sticker on the door like pictured below. What are the two psi values on your sticker like highlighted below?

 

[Scubaz66]

When you open the front driver door, there’s a sticker on the door like pictured below. What are the two psi values on your sticker like highlighted below?
View attachment 63774

Hey Jimmy! Good to hear from you again. You and I discussed this problem a few months ago. You gave me a VERY GOOD synopsis regarding the 20% difference between actual tire pressure and what the cluster states that causes the notification amber Low Tire Pressure to register. Because I don't tow heavy loads except for maybe once every 6 months I chose to lower my tire pressures 55psi all the way around for a smoother ride. This only worked for a few months at a time. Sometimes a week or two sometimes 6 months. In order to resolve the issue the dealership would air up the tires according to the above label placed by the Automobile Manufacturer. In my case it's 60psi frt/65psi rear. Then drive the vehicle until the light reset. After several trips to the dealership trying to get the dealer to contact RAM for a better understanding and going with your synopsis I decided to up the rear tire pressure to 60psi, 5psi under the sticker recommendation. I kept the front at 55psi, 5psi less than sticker. Still have the same problem. I purchased a new Digital Gauge and set the fronts to 55psi and rear to 60psi. After a few days the cluster identified a low tire (52psi in passenger front tire) I checked the tire pressure with my new gauge and it read 56psi. Divers side was still at 55psi. Rears were both at 60psi where I set them. I didn't compare the difference on the cluster because they were not in the Red. No one is entering my garage and adding or removing air from the tires. And I do understand weather dictates pressure differences given the ambient temperature. Personally I believe the Valve Stems may be faulty, maybe the relay sending unit or the receiver side isn't picking up the correct psi the valve stems are sending. Given all the issues with the newest UConnect5 system, it could be another software issue that hasn't yet been resolved. I have two other family members who own 2021/2022 like trucks. All 3 RAM 2500 Big Horns. My Brothers truck never resets. He changes tires about every couple months depending on the loads he hauls. Yep! He has two sets of tires for his truck. His son has the same issue, but he just ignores the problem, Couple of other people on the forum also ignore the problem. I'm persistent and want things to work correctly. Again! Thanks for lending an ear. Its always good to have other knowledgeable individuals giving their thought process!

 

[Brutal_HO]

Why don't you just get setup with AlfaOBD or Jscan and set the threshold to whatever you want and/or turn the TPMS off (set to TPIS)?

 

[Scubaz66]

Why don't you just get setup with AlfaOBD or Jscan and set the threshold to whatever you want and/or turn the TPMS off (set to TPIS)?

Thanks Brutal_HO. I've tried to get either of the two local dealers to make the changes for me, but they state they aren't allowed. I live in a pretty small town and haven't found someone who has the equipment and can do this. Can you lead me to the directions to turn this system off? Didn't know I could do this. Thanks for the info!

 

[AH64ID]

Thanks Brutal_HO. I've tried to get either of the two local dealers to make the changes for me, but they state they aren't allowed. I live in a pretty small town and haven't found someone who has the equipment and can do this. Can you lead me to the directions to turn this system off? Didn't know I could do this. Thanks for the info!

Are you an android or apple user?

 

[Jackmup]

Considering the garbage they sell the truck with it should be changeable when you change tires. I want a truck not a 1/4 mile car with bologna skinz. I changed my tires as soon as I got the truck. Just because the big three all sell em with garbage doesn't mean we can't revisit 1990 when they came with real tires

 

[Nothotdog]

Thanks Brutal_HO. I've tried to get either of the two local dealers to make the changes for me, but they state they aren't allowed. I live in a pretty small town and haven't found someone who has the equipment and can do this. Can you lead me to the directions to turn this system off? Didn't know I could do this. Thanks for the info!

I can't attest to JScan or Alfa OBD, but I used the AEV ProcalSnap to change my TPMS. I am not very mechanically inclined and it was fairly simple to do. With a '22 you shouldn't need to worry about getting the right model (with a '23 I had to make sure it was a "BF" model, as "BE" would not work).

ProcalSnap will only do three things, change TPMS setting, change tire size, and change axle ratio.

It is pretty simple to install and operate (they have instructions on their site and there are some good videos on Youtube as well):

1. Pop out the OBDII connector from its holder (there are clasps on each side, my clasps were on the dashboard side and not on the floorboard side so I had to kind of reach in from below)
2. Pop out the pin locks from the OBDII (this was the most difficult part for me, as those gray pin locks were stubborn, I used a very small screw driver to push the pins down and finally got it to pop out)
3. Insert the bypass pins (they give this to you) in the correct ports on the OBDII
4. Put the OBDII back in place
5. Insert the other end of the bypass into the correct green star connector (I had to pop out the panel for the light controls to reach inside the dash, but it was pretty simple to pop out)

Once installed, it is very simple to use (again, they have instructions printed for this as well). You first pair it with your truck (which will make it forever linked to your truck) by pressing the ignition twice to "Run", then plugging in the Snap. You then press and hold the brake pedal and the cruise control on/off button. The horn honks three times and you are now paired.

To change TPMS, you put the radio on AM, then go to the equalizer and change the Bass, Mid, Treb to the values you want (for me it was 0 3 5) and do another set of Brake press + one of the buttons for the cruise control (the buttons are different for changing TPMS, tire size, and axle ratio, it will tell you in the instructions).

Again, for me, the most time consuming part was trying to get the gray pin locks out of the OBDII, other than that it was pretty quick.

 

[Scubaz66]

Are you an android or apple user?

I use Apple IPhone 14 Pro Max

 

[AH64ID]

I use Apple IPhone 14 Pro Max

Get JScan, a VLinker MX+, and a KaoTech security bypass cable.

Changing the threshold or swapping back and forth with TPIS/TPMS is easy.

Lots of other possibilities too.

 

[Scubaz66]

Considering the garbage they sell the truck with it should be changeable when you change tires. I want a truck not a 1/4 mile car with bologna skinz. I changed my tires as soon as I got the truck. Just because the big three all sell em with garbage doesn't mean we can't revisit 1990 when they came with real tires

I agree!! Tires wear out and are replaced several times during the life of a vehicle. The Manufacturer Label placed on the truck when new only identifies tire pressures for the tires that the manufacturer placed on the vehicle when it came off the assembly line. Once a consumer changes or replaces worn tires logic says to use the tire pressure information printed on the sidewall of the replacement tires. Only the manufacturer of the actual tire can identify the safe pressures for the tire in question. I'm an old DOT CDL instructor and spent several classroom hours on teaching tire safety. It's ridiculous to give the consumer the ability to set the STPMS anywhere from 15psi to 95psi when adding air to anything other than 60psi front and 65psi rear if the system continually trips if those pressures are not met. I'm surprised the NHTSA allows the automotive manufacturers to get away with this safety regulation. My dash continues to tell me I have low air pressure even when I check my tires with a Digital Gauge. At some point during a long trip I'm not going to know if I actually have a low tire until it gets low enough to cause steering problems or other issues. The system doesn't meet NHTSA safety regulations!!!!