Tazer JL vs TPMS

BillArnett

New member
Of course, the main reason I bought my Tazer JL was to fix the speedo for my larger tires. It works just great for that.

But I also wanted to adjust the TPMS threshold so that I wouldn't get a zillion warnings every time I aired down for the trails. I followed the instructions but the results confused me. I set the threshold to 12 psi and aired down a tire to see what it would do. I get nonsense like this:
nonsense.jpg
That wouldn't be so bad except that it shows me this every time I start the engine. So I emailed customer support at Z Automotive hoping that I had just done something wrong. It's the weekend so I figured I might hear back next week sometime. But I got a response within the hour. Here's what he said:

"FCA set the minimum to 25psi. Likely the minimum allowed by law. I’m trying to force an override but for now the other option is to just turn TPMS off altogether."

I then asked if I would still get the TPMS readouts if I turned it off altogether and he again replied immediately:

"No they’d go away. The tpms pressure adjust is really meant for oversized tires that run lower pressures not for airing down when off roading. They don’t want you to forget to air back up on-road."

So I'm really happy with Z-Automotive's customer support. And pissed at FCA for being such a nanny. But at least I now understand why it's doing what it's doing.
 

13_gecko_rubi

New member
Of course, the main reason I bought my Tazer JL was to fix the speedo for my larger tires. It works just great for that.

But I also wanted to adjust the TPMS threshold so that I wouldn't get a zillion warnings every time I aired down for the trails. I followed the instructions but the results confused me. I set the threshold to 12 psi and aired down a tire to see what it would do. I get nonsense like this:
View attachment 5791
That wouldn't be so bad except that it shows me this every time I start the engine. So I emailed customer support at Z Automotive hoping that I had just done something wrong. It's the weekend so I figured I might hear back next week sometime. But I got a response within the hour. Here's what he said:

"FCA set the minimum to 25psi. Likely the minimum allowed by law. I’m trying to force an override but for now the other option is to just turn TPMS off altogether."

I then asked if I would still get the TPMS readouts if I turned it off altogether and he again replied immediately:

"No they’d go away. The tpms pressure adjust is really meant for oversized tires that run lower pressures not for airing down when off roading. They don’t want you to forget to air back up on-road."

So I'm really happy with Z-Automotive's customer support. And pissed at FCA for being such a nanny. But at least I now understand why it's doing what it's doing.
Pissed at FCA for being a nanny? You mean following the law? You get to voice your opinion every other November :)

Sent via....
 

doubletapdaddy

Caught the Bug
"No they’d go away. The tpms pressure adjust is really meant for oversized tires that run lower pressures not for airing down when off roading. They don’t want you to forget to air back up on-road."

Although it has never really bothered me, I never fully grasped the rationale of minimum threshold. I can definitely respect trying to remind people to air back up when going back on road. I think it's pretty brilliant safety strategy, and something I can definitely appreciate. At least they gave me the choice to opt out on the Active Safety Group.
 

BillArnett

New member
It seems to me that the right thing to do is to have TWO thresholds: one for normal use and one for off-road. The former could be in effect when in 2HI and the later in the 4wd modes. If this wouldn’t be legal according to the letter of the law then I suspect FCA could get an exception. After all, while it’s possible to drive on public streets in 4wd it’s a very bad idea (except perhaps when it snowing). Or they could have made it possible for such a thing to be done by the likes of the Tazer JL. It is possible to turn of the TPMS entirely; why is that better? Perhaps there’s something more complicated going on that I’m not aware of? Or perhaps they just got lazy. There should have been a way to recalibrate the speedometer for bigger tires without a third-party add-on, too. Surely FCA knows that many Wrangler owners change tires.

But anyway, it’s nice to understand why it does what it does.
 

13_gecko_rubi

New member
It seems to me that the right thing to do is to have TWO thresholds: one for normal use and one for off-road. The former could be in effect when in 2HI and the later in the 4wd modes. If this wouldn’t be legal according to the letter of the law then I suspect FCA could get an exception. After all, while it’s possible to drive on public streets in 4wd it’s a very bad idea (except perhaps when it snowing). Or they could have made it possible for such a thing to be done by the likes of the Tazer JL. It is possible to turn of the TPMS entirely; why is that better? Perhaps there’s something more complicated going on that I’m not aware of? Or perhaps they just got lazy. There should have been a way to recalibrate the speedometer for bigger tires without a third-party add-on, too. Surely FCA knows that many Wrangler owners change tires.

But anyway, it’s nice to understand why it does what it does.
The difference you fail to see is there are many federal laws which FCA actually has to follow. Some examples

1) Tire size - so if they let you change tire size in the Jeep. How do they know that you didn't just change tire size to alter the odometer reading which is a federal crime? In order for the OEM to allow it there has to be a way for them to verify it. This is why you can do it at the dealer now. You never could before.

2) TPMS - This is all covered by the tread act. Again FCA would need validation to be able to change it. To properly validate it calculations would have to be done based on load rating vs weight of every tire made along with the variances between each Jeep. Could it be done yes. Would you pay a small fortune to have it done as all that testing isn't free?

Same reasons why stop/start can't be disabled, why they aren't lifted from factory, etc etc. The OEM has to sell legal vehicles, it's not laziness at all. Some things are better left to the aftermarket.

Sent via....
 

notnalc68

That dude from Mississippi
The difference you fail to see is there are many federal laws which FCA actually has to follow. Some examples

1) Tire size - so if they let you change tire size in the Jeep. How do they know that you didn't just change tire size to alter the odometer reading which is a federal crime? In order for the OEM to allow it there has to be a way for them to verify it. This is why you can do it at the dealer now. You never could before.

2) TPMS - This is all covered by the tread act. Again FCA would need validation to be able to change it. To properly validate it calculations would have to be done based on load rating vs weight of every tire made along with the variances between each Jeep. Could it be done yes. Would you pay a small fortune to have it done as all that testing isn't free?

Same reasons why stop/start can't be disabled, why they aren't lifted from factory, etc etc. The OEM has to sell legal vehicles, it's not laziness at all. Some things are better left to the aftermarket.

Sent via....

IMG_2679.JPG



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BillArnett

New member
The difference you fail to see is there are many federal laws which FCA actually has to follow. Some examples

1) Tire size - so if they let you change tire size in the Jeep. How do they know that you didn't just change tire size to alter the odometer reading which is a federal crime? In order for the OEM to allow it there has to be a way for them to verify it. This is why you can do it at the dealer now. You never could before.

2) TPMS - This is all covered by the tread act. Again FCA would need validation to be able to change it. To properly validate it calculations would have to be done based on load rating vs weight of every tire made along with the variances between each Jeep. Could it be done yes. Would you pay a small fortune to have it done as all that testing isn't free?

Same reasons why stop/start can't be disabled, why they aren't lifted from factory, etc etc. The OEM has to sell legal vehicles, it's not laziness at all. Some things are better left to the aftermarket.

Sent via....

OK, I get it. Thanks.

(The speedometer/odometer could easily be recalibrated automatically from the GPS (if one is present). It's probably best to keep them primarily based on tire revolutions since GPS doesn't always work quite right but it could still recalibrate based on GPS readings from nice straight roads. But this sounds like the kind of thing you would find on a luxury car not a Jeep :-(
 

notnalc68

That dude from Mississippi
OK, I get it. Thanks.

(The speedometer/odometer could easily be recalibrated automatically from the GPS (if one is present). It's probably best to keep them primarily based on tire revolutions since GPS doesn't always work quite right but it could still recalibrate based on GPS readings from nice straight roads. But this sounds like the kind of thing you would find on a luxury car not a Jeep :-(

Yeah, that sounds expensive, too.


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Saddletramp

Member
Sometimes depending on wheel offset they can have trouble picking them up to initiate. Rotate the fronts and rears. It won't lose the two it already recognizes but will likely find the other two and should be good

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Thank you Sir, was actually wondering if this might help the other two report in... appreciate it.
 

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