Calibration after new tires

[ejewels]

Hey all,

So I have to take my jeep into the dealer for a recall (control module software updates - something about properly monitoring emission related stuff) and since I just swapped tires to 34" I was going to have them update my tire size in the ECU. If they are cheaper than buying a mini tazer and the like, I'll just do dealer for now. I have a couple of questions:

1) What do I call this so the dealer understands and doesn't mess anything up? Updating the speedo for a new tire size?
2) Do they actually measure the tire size on my rim/jeep or just use the numbers on the tire for the size?
3) Will updating the tire size in the computer help with shift points and general auto trans operation? I know I'm on the 3.45 gears and its to be expected for it to not run as good with larger tires, but I did notice and I'm wondering if highway driving will get better. Seems to gear hunt more in general. But I definitely notice more past 70mph.

Sponsored

 

[jludave]

1) What do I call this so the dealer understands and doesn't mess anything up?

Flash/update/re-program vehicle for larger tire size.

2) Do they actually measure the tire size on my rim/jeep or just use the numbers on the tire for the size?

Ask them. Better yet, tell them how you'd like it done.

3) Will updating the tire size in the computer help with shift points and general auto trans operation?

Yes. That's the whole point of having the vehicle updated for the larger tire size.

Good luck and enjoy your ride!!

 

[ejewels]

Flash/update/re-program vehicle for larger tire size.



Ask them. Better yet, tell them how you'd like it done.



Yes. That's the whole point of having the vehicle updated for the larger tire size.

Good luck and enjoy your ride!!

Thanks. Good to know. I thought people mostly did it for the speedo calibration.

 

[jaymz]

You can likely buy JSCAN and the necessary hardware to DIY for less than the dealer will charge you to do it and will then have the ability to make other changes down the road should you want/need to.

 

[jludave]

Thanks. Good to know. I thought people mostly did it for the speedo calibration.

Well, it fixes that too.

 

[ejewels]

You can likely buy JSCAN and the necessary hardware to DIY for less than the dealer will charge you to do it and will then have the ability to make other changes down the road should you want/need to.

I've thought about this too. I guess I should call and see what the price will be. I don't really plan on doing anything else other than setting the new tire size. I just don't know exactly what I'd have to order going the JSCAN route. Seems like a bunch of random adapters and such from what I've seen lol.

 

[Riverjeep]

Hey all,

So I have to take my jeep into the dealer for a recall (control module software updates - something about properly monitoring emission related stuff) and since I just swapped tires to 34" I was going to have them update my tire size in the ECU. If they are cheaper than buying a mini tazer and the like, I'll just do dealer for now. I have a couple of questions:

1) What do I call this so the dealer understands and doesn't mess anything up? Updating the speedo for a new tire size?
2) Do they actually measure the tire size on my rim/jeep or just use the numbers on the tire for the size?
3) Will updating the tire size in the computer help with shift points and general auto trans operation? I know I'm on the 3.45 gears and its to be expected for it to not run as good with larger tires, but I did notice and I'm wondering if highway driving will get better. Seems to gear hunt more in general. But I definitely notice more past 70mph.

Hey, if you do get it done or at least a price from dealer can you pop back on here and tell us what you found?

 

[tomk62]

Hey all,

So I have to take my jeep into the dealer for a recall (control module software updates - something about properly monitoring emission related stuff) and since I just swapped tires to 34" I was going to have them update my tire size in the ECU. If they are cheaper than buying a mini tazer and the like, I'll just do dealer for now. I have a couple of questions:

1) What do I call this so the dealer understands and doesn't mess anything up? Updating the speedo for a new tire size?
2) Do they actually measure the tire size on my rim/jeep or just use the numbers on the tire for the size?
3) Will updating the tire size in the computer help with shift points and general auto trans operation? I know I'm on the 3.45 gears and its to be expected for it to not run as good with larger tires, but I did notice and I'm wondering if highway driving will get better. Seems to gear hunt more in general. But I definitely notice more past 70mph.

2) it should be measured to get the actual size, if an accurate calibration matters to you (i.e. your 34" tire is actually less than 34").

The ECRI can auto calculate and calibrate the size based on your GPS speed compared to how fast your Jeep's spedo says.

 

[jludave]

I just don't know exactly what I'd have to order going the JSCAN route.

https://www.zautomotive.com/product/z_sgw/

https://www.zautomotive.com/product/z_sgw_ext/

https://jscan.net/supported-and-not-supported-obd-adapters/

And of course the JSCAN app.

 

[ejewels]

2) it should be measured to get the actual size, if an accurate calibration matters to you (i.e. your 34" tire is actually less than 34").

The ECRI can auto calculate and calibrate the size based on your GPS speed compared to how fast your Jeep's spedo says.

nice, is that all I'd have to purchase? (just the ECRI itself)

 

[ejewels]

https://www.zautomotive.com/product/z_sgw/

https://www.zautomotive.com/product/z_sgw_ext/

https://jscan.net/supported-and-not-supported-obd-adapters/

And of course the JSCAN app.

thanks for the links!

 

[jludave]

nice, is that all I'd have to purchase? (just the ECRI itself)

If you wish to go the ECRI route, you need to purchase the bundle that includes the Security Gateway Bypass and the ECRI module for the 2018+ JL.

 

[ejewels]

If you wish to go the ECRI route, you need to purchase the bundle that includes the Security Gateway Bypass and the ECRI module for the 2018+ JL.

would that be the "lifetime vehicle unlock" they charge for? You can either buy it now or "purchase later" and the price drops like $40 if you don't buy it. And from what I see, this seems easier than all the wiring harnesses than with JSCAN solutions?

 

[jludave]

@ejewels

I believe you need to purchase the unlock for 1 vehicle one way or the other. I believe it is done upfront via the lifetime purchase or in the app.

The harness I linked to above is optional, but many purchase it to use with the ECRI bypass module or a Tazer to make the connections easier.

 

[ejewels]

@ejewels

I believe you need to purchase the unlock for 1 vehicle one way or the other. I believe it is done upfront via the lifetime purchase or in the app.

The harness I linked to above is optional, but many purchase it to use with the ECRI bypass module or a Tazer to make the connections easier.

thanks, are you talking about the extension cable you linked? In their ad, it looks like it just plugs in right under the dash/steering wheel. Is this not the actual case for our JLs? I'll buy it if its necessary. at $130 (or more if I get that cable) and a lifetime of changes, I'm sure this is the best route considering I guarantee my dealer will charge more. I'm also assuming this won't void warranty? Back when I had my APR tuned GTI, the dealer could tell if you flashed your vehicle... not sure if the same applies with Jeep.

Sponsored