I just bought a set of OEM 20" wheels for my 07 Tahoe. Are there any adjustments I need to make to the computer? According to my calculations the 17's are 31.7" tall and the 20" is 31.9" tall. Also is the gearing different in the models with 20" wheels? I have 3.43:1 gears.

 

My gear is 3:73 on my LTZ with the 20's

 

I am sure it will be fine, I just wanted to ask. I know that diameter is the big thing, followed by rotating mass.

 

Take it into your local dealer and have them update the calibration for OEM 20" wheels/tires, they will have to obtain a new VCI from Techlink, GM does not charge the dealer for this service however the dealer may charge you up to $50 for the update but it's worth it.
Not only does this recalibrate the speedometer but it also sets the correct algorithm for the ABS brakes and Stabilitrak so that when you hammer the brakes and jerk the steering wheel to avoid a crash the computer isn't confused by the amount of contact patch of the larger tires.

Dave

 

Is that something the Flashpaq could do for me? That is my next purchase.

 

No it is not.

 

I just called the dealer and was quoted $225. He said I have to buy the new program for the BCM and ECM which costs $75 from the GM. He said I can't reuse my valve stems and I have to pay 2 hours labor. And since I am having the BCM reprogrammed I may need new door remotes??? Can't I just reprogram following the instructions in the manual? Am I getting raked over the coals???

Thanks.
Kevin

 

Contact another dealer these guys either don't know what they are doing or they are trying to make a profit.
I’m all for making money so long as it doesn’t involve lying to the customer.

You for sure will not have to replace your keyless remotes and you can take that to the bank. 2 totally unrelated devices.

Part # for the TPM Sensor is 15254101 and this part number is the same for 17" and 20" wheels and you can take this to the bank as well.

GM does not charge for a new VCI number to update for the OEM 20" wheels provided they are the factory wheels and tires and they have to take the dealers word for this, you can take this to the bank as well.

The only thing that dealer will need to do is obtain a new VCI from Techlink and retrieve and install the download (20 minutes max if they are on hold for the prerequisite 15 minutes with Techlink) and then relearn the TPM sensors to the truck (a 2 minute job max).

Now I would expect a dealer to charge for this service since it does take some of there time but anything over 1 hour labor is ridiculous.

 

Thanks that is what I figured. There is a GMC dealer here in town and I know that after my wife's accident the body shop went through them for our parts. I will call them in the morning.

Thanks.

Kevin

 

I knew that couldn't be true because like I mentioned earlier when my wife was in her wreck the tire shop put the rubber style valve stem in the new wheel and the TMS wouldn't recognize it so we had to order the metal/plastic style one and they popped the tire off put it in and off we went.
This pisses me off the more I think about it. I want to believe that they don't know what they are talking about and not trying to rip me off. But I also know that they have customized several of the Tahoes on their lot and I would think that they had to have reprogrammed them for the 20" wheels. So who knows???