Model 3 TPMS off by 3-5 PSI?

[tvisdog]

Compared to 2 different tire pressure meters (one digital one analog), my air compressor, and the inflator machines at two different tire shops, the TPMS readings in my Model 3 are consistently low by 3-5 PSI. Normally I wouldn't care, but the car starts to throw warnings at 38 PSI, which is actually about 43 PSI and is about where it should be when it's very cold.

Has anyone else had this issue? I contacted the Service Center but they didn't have any suggestions and said they will need to have my car for "a few days" to diagnose this issue. I'd like to avoid that if there's a simple fix.

 

[Kirby64]

Mine are spot on with analog gauges. If it's off by 3-5 psi that seems like a problem.

 

[SomeJoe7777]

--> Denver, CO

Altitude is the cause of the issue. The pressure meters you're using on the valve stem read differential pressure between the tire and the atmosphere, as they're supposed to. But the TPMS modules compare the tire internal pressure to a fixed sea-level pressure reference, resulting in false low readings.

No fix until Tesla compensates in software.

 

[tvisdog]

--> Denver, CO

Altitude is the cause of the issue. The pressure meters you're using on the valve stem read differential pressure between the tire and the atmosphere, as they're supposed to. But the TPMS modules compare the tire internal pressure to a fixed sea-level pressure reference, resulting in false low readings.

No fix until Tesla compensates in software.

Interesting! I hadn't thought of that. Is this a known/documented issue? If it is, I'm content to wait for a fix. If not, then I'm more likely to push on the Service Center to get them to diagnose it.

 

[JeffK]

Mine are off by exactly 1 PSI or perhaps my digital gauge is off by 1 PSI...

 

[commasign]

Digital gauge. PSI within 1 of the car.

 

[voip-ninja]

Interesting! I hadn't thought of that. Is this a known/documented issue? If it is, I'm content to wait for a fix. If not, then I'm more likely to push on the Service Center to get them to diagnose it.

Please push them on it. I dropped my car off today and they made a point both today and in a voicemail message they left for me yesterday that they didn't have time to address any other concerns I might have since they are heavily backlogged and need to work the issues they have appointments for.

I observed the same problem in this thread and like you I'm at 5K+ feet above sea level;

Model 3 TPMS sensors are junk

This should be mickey mouse stuff... and if Tesla does not want to fix it then they need to lower the TPMS warning threshold so it doesn't go off for us high altitude people if we set the tires, as Elon Musk himself recommends, at 39 PSI if we want "comfort".

 

[rdfield]

I live five miles outside of las Cruces New Mexico at 4400 feet- and my tire pressure is spot on. Why an additional 800 feet in altitude would make such a difference I have not a clue. On your next service center visit you could ask that the TPMS be checked on all you tires.

 

[StellarRat]

Mine are all within 1 psi of a digital gauge.

 

[SomeJoe7777]

Interesting! I hadn't thought of that. Is this a known/documented issue? If it is, I'm content to wait for a fix. If not, then I'm more likely to push on the Service Center to get them to diagnose it.

No, it's not documented. @voip-ninja above has the same issue, and in his thread we arrived at altitude as the likely cause, especially since the pressure differences he's seeing are, like yours, exactly what would be expected if the TPMS modules used a sea-level reference.

However, no one has proven this. It may be worth it to formally make a service appointment and let Tesla fully troubleshoot. Maybe we will get confirmation that we're correct, or maybe we'll learn something different.

 

[ngogas]

I live in Utah at about 4400 level and mine is spot on.

 

[Supertester777]

Mine is perfect. Every time I go to America’s tires I can see the actual pressure change in near real-time and it matches the settings at their pump.

 

[tvisdog]

Please push them on it. I dropped my car off today and they made a point both today and in a voicemail message they left for me yesterday that they didn't have time to address any other concerns I might have since they are heavily backlogged and need to work the issues they have appointments for.

I observed the same problem in this thread and like you I'm at 5K+ feet above sea level;

Model 3 TPMS sensors are junk

This should be mickey mouse stuff... and if Tesla does not want to fix it then they need to lower the TPMS warning threshold so it doesn't go off for us high altitude people if we set the tires, as Elon Musk himself recommends, at 39 PSI if we want "comfort".

Out of curiosity, did you get a loaner? And if so, what did they give you?

 

[rtanov]

Good news it they seem to have lowered the low pressure warning trigger point with V9 - mine are now showing at 36 psi in the cold mornings and there is no warning. I like that.

 

[voip-ninja]

Out of curiosity, did you get a loaner? And if so, what did they give you?

I do have a loaner, it's a pretty old 1st generation S85.

 

[voip-ninja]

Mine is perfect. Every time I go to America’s tires I can see the actual pressure change in near real-time and it matches the settings at their pump.

Yes, you are sea level so it's "perfect".

 

[tvisdog]

Went to the service center today and spent more than 3 hours arguing about this issue with various individuals including the manager.

I was told, at various times, that:

1. This is a known issue and Tesla's engineers are working on a fix.
2. This is a known issue but it cannot and will not ever be fixed.
3. This is a known issue that affects all cars with TPMS at altitude.
4. There is no issue, the TPMS is working correctly and agrees with their gauge.
5. There is no issue, but the TPMS disagrees with all other gauges because no tire gauges work properly at altitude except for one they found in the service center. The ambient air pressure has no effect on tires and I should inflate them until the TPMS says they are properly inflated. Tesla will not cover damage to my tires that occurs as a result of following this advice.
6. There is no issue, but the TPMS disagrees with all other gauges because tire gauges have a variance of +/- 5 PSI and every one I have tried just happens to be off by exactly the same amount.

In the end, they refused to acknowledge or fix the issue and refused to provide any documentation of the answers that I was given. No one, including Michael, the manager, would take any ownership of the pro I have started an executive escalation to review their decision.

While I hesitate to recommend anyone go through the frustrating waste of time I endured today, I suspect it might be helpful if other people who are having this issue also complain loudly.

 

[TT97]

My TPMS seem to be about 2-3 psi low (and am close to sea level so that is not the issue). I bought a second tire gauge because I thought that was the issue but both gauges read the same (and borrowed a third gauge just to be extra sure). I like to keep my tires at 45 psi so have not run into low pressure warnings (nor do we have cold weather).

 

[voip-ninja]

Went to the service center today and spent more than 3 hours arguing about this issue with various individuals including the manager.

I was told, at various times, that:

1. This is a known issue and Tesla's engineers are working on a fix.
2. This is a known issue but it cannot and will not ever be fixed.
3. This is a known issue that affects all cars with TPMS at altitude.
4. There is no issue, the TPMS is working correctly and agrees with their gauge.
5. There is no issue, but the TPMS disagrees with all other gauges because no tire gauges work properly at altitude except for one they found in the service center. The ambient air pressure has no effect on tires and I should inflate them until the TPMS says they are properly inflated. Tesla will not cover damage to my tires that occurs as a result of following this advice.
6. There is no issue, but the TPMS disagrees with all other gauges because tire gauges have a variance of +/- 5 PSI and every one I have tried just happens to be off by exactly the same amount.

In the end, they refused to acknowledge or fix the issue and refused to provide any documentation of the answers that I was given. No one, including Michael, the manager, would take any ownership of the pro I have started an executive escalation to review their decision.

While I hesitate to recommend anyone go through the frustrating waste of time I endured today, I suspect it might be helpful if other people who are having this issue also complain loudly.

When I had my car in for service for five days I didn’t even bring it up since they made a big deal about not doing anything “extra” due to their backlog.

Supposedly V9 lowered the level where TPMS will throw faults, however I am still on V8 (service didn’t do firmware update on my car while they had it) so no way for me to verify.

People rave about the great service at the Broadway S.C. but frankly I haven’t been that impressed.

 

[boriszima]

Which inexpensive digital gauges are you guys using? It is cool that car actually shows pressure per tire, in my other car it was just warning that came on fairly deep into deflation, had to figure out which tire.