OK you smart{ with all due respect} guys I just had my dealer reprogram the computer in my 07 tahoe to handle the 305/40's and the 22 wheels... Now when I start the car the tire pressure sensor goes off saying check right rear, left front, left rear, and right front tire pressure.. I have to press the controls and it takes 5 or 6 pushes to get it to stop... Yes the sensors were placed in the new wheels..I will take it back to the tire ppl and see if they can check the sensors.... any ideas would help me... thanks marie

 

Have the dealer reprogram the TPMS with the gun and also reset the low pressure threshhold to 31psi via Tech-2's service menu.

 

So how bad is it not to reprogram your car.
I got 305/45/22....

 

Maries- Bring your truck back to the dealerifthey charged you for this service. They did not complete reprogram. As ZX stated they have to set new pressure levels for new tires. They also have to program tire & wheel size in ECM. My dealer charged me for 1.5 hours on labor for this but still didn't get it right. They set pressure but with factory specs. The best thing to do is go to a Caddy dealer if you only go up to 22" wheels since they're more verse in the 22" programming Remember some Escaladescome with 22" wheels. I did this when I needed a tire rotation because my Chevy dealer stated that they could not do rotation for my22"wheels (no reason given) I then went to my local Caddy dealer for this service.

 

I took my truck to my local chevy dealer and asked them to reprogram the ECM for the larger wheels. The service tech told me that they no longer do that. They said that from a 17" to a 20" is the same diameter due to the different tire sizeand thats why it was not required. Did they B**ll SH*T ME?? Thanks...

 

I kinda heard the same thing.
I went from from 17s to 22's with a lower profile tire so it only changed my diameter by 1/2 an dinch.

 

yeah, they bs'd you. I try to cover myself for the future. Transmission problems within warranty period due to going up in diameter. These are the games the dealers play. At least I have receipts stating I was charged for upgrades. Always CYA!!!

 

When changing tire/wheel size always have the dealer recalibrate the computer, they need to obtain a new specific VCI # based on the size of the new tires.

This is done not only to correct for the tire diameter but also to set the correct algorithm for the ABS brakes and Stabilitrak system, which measurements are based on both diameter and tread width.

 

Thnaks for the info ZX.