Help with Speedometer Recalibration

[jareds]

I’m not sure how to get the speedometer recalibrated on my 21 Tahoe after putting 22” wheels on in place of the 20” it came with. Gm and my dealer will not help because they are not gm wheels.. any help is appreciated. The speedometer is about 3 mph off.

 

[Doubeleive]

IF and big IF there are any handheld tuner options for your vehicle then they generally have a option to adjust for tire size
pretty sure blackbear is not doing 2021's yet or they just won't be, you could look around at diablo or something-maybe I haven't looked myself
your options maybe limited GM is locking these down more and more. you could maybe try another gm dealer and ask them to set the wheel size to 22 instead of 20 just because they are not gm wheels doesn't make any difference but presume they are going to charge you to do that if they are even willing.

 

[therealbofa]

Check out the Pulsar LT. Seems like the only option to disable afm on these engines with the 10 speed and has added features to disable ESS, change speed limiter and throttle sensitivity, and can recalibrate for different tire sizes. It isn’t cheap though.

 

[jareds]

So the dealer is willing to change it if they could but GM won’t give them the unlock code to change the programming, they suspect if they get another customer Tahoe in to get 22” wheels installed from GM they can use the RPO code from those GM wheels to call GM to remotely unlock both that vehicle and mine on two different calls. They’re not sure if GM will catch that the code was used twice but they’re going to call me to bring it in and try anyway. But I don’t know when that will be so I was hoping there was a solution out there I just hadn’t come across yet. So I’ll look into the Pulsar Lt and will have to go that route if GM catches the code being used twice. Just didn’t want to shell out more cash to make this right after almost $5k of wheels and tires!!

 

[ljn21]

Check out the Pulsar LT. Seems like the only option to disable afm on these engines with the 10 speed and has added features to disable ESS, change speed limiter and throttle sensitivity, and can recalibrate for different tire sizes. It isn’t cheap though.

I don’t think it works on the SUVs yet, only the trucks.

 

[68Chevysspu]

Wow! This is all getting just too “1984” these days.

 

[therealbofa]

I don’t think it works on the SUVs yet, only the trucks.

Their website says it does.

ETA: actually it was a retailer site that said it does. I’ll email range and confirm.

 

[Doubeleive]

part of the issue is GM doesn't want a hacker getting into the system now that there is more and more electronic (electric) controlled parts a hacker could wreck havoc on a vehicle, steal them, drive it away remotely, cause a accident remotely, that would be bad press for them.
they want to sell you a new toy and say go play with it nicely now.

 

[RST Dana]

I’m not sure how to get the speedometer recalibrated on my 21 Tahoe after putting 22” wheels on in place of the 20” it came with. Gm and my dealer will not help because they are not gm wheels.. any help is appreciated. The speedometer is about 3 mph off.

Measure total height on both wheels. (Top of the tires)If it’s the same, nothing is needed.

 

[ljn21]

Their website says it does.

ETA: actually it was a retailer site that said it does. I’ll email range and confirm.

I emailed a couple of weeks back and they confirmed trucks only, maybe it changed since.

 

[Dustindu4]

You have 3 options, I looked into this on my 2017 yukon

1) waste a lot of money and have a dealer do it. They have to pay GM around 100-150 to send in a new system software file. Plus whatever they charge for labor. If the place you went to won't do it, try another place.
2) buy a tuner to update your tire revolution/diameter settings. You can also mess with a lot of neat other things.
3) don't do anything. At most your speed at 70 will be 1 mph off. GPS it. You will realize it isn't enough to do option 1 and 2

 

[therealbofa]

I emailed a couple of weeks back and they confirmed trucks only, maybe it changed since.

Thanks For sharing. They confirmed by email that it’s not compatible and said I would need one of their handheld devices from their other brands. Now I’m curious what that would be.

 

[ljn21]

Thanks For sharing. They confirmed by email that it’s not compatible and said I would need one of their handheld devices from their other brands. Now I’m curious what that would be.

Same, I don’t think there is one

 

[Jimmyy]

The wheel size shouldn't matter. It would be the tire size. Can you get a similar size (conference) tire?

 

[jareds]

Ahh okay bummer thanks for checking..just have to wait for the dealership to get another Tahoe in needing 22” wheel upgrade over factory for now then. Thankfully with the wireless Apple CarPlay my Waze app shows the gps speed on the navigation when I’m driving so I know my true speed.

 

[therealbofa]

Got another response today telling me the ecm is different from the Sierra and saying they don’t currently have plans to make a version of the pulsar for the Yukon/Tahoe.

I did follow up asking what other handheld they were referring to and will post back if anything comes of it. I went through all of their sister brands and nothing comes up for 2021 or 2022.

 

[RST Dana]

I’m not sure how to get the speedometer recalibrated on my 21 Tahoe after putting 22” wheels on in place of the 20” it came with. Gm and my dealer will not help because they are not gm wheels.. any help is appreciated. The speedometer is about 3 mph off.

You haven’t replied with the total height of both yet. If they are the same overall height, you don’t need to do anything but drive it.

 

[jareds]

I’m not sure of the total height I haven’t had time to check both sets. The speedometer is off 2-3 mph below 60 and 3-4 above 60. It’s reading faster than the GPS indicated speed, so tires must be a little shorter than stock.

 

[Mike jolly]

I’m not sure how to get the speedometer recalibrated on my 21 Tahoe after putting 22” wheels on in place of the 20” it came with. Gm and my dealer will not help because they are not gm wheels.. any help is appreciated. The speedometer is about 3 mph off.

Obd genie .com has the fix

 

[dhmcfadin89]

Obd genie .com has the fix

Please elaborate.