I called all three dealers in my area to get the speedo changed for my bigger tires.
#1-We can only calibrate up to 1/2 size.
#2-Truck should automatically adjust to tire size throught the computer.
#3-We cannot do it, but Les Schwab where you bought the tires has the correct tool.

I have a call into the service manager at the first dealer, as my truck sat there all day on Tues. to get the automatic idle control enabled, and was told at the end of the day this option is V.I.N. specific, and couldn't be done on my truck.

I'd like to use this 5 star servey as an opportunity to get my idle enabled and speedo adjusted, and need the sequence so as to hand it to the service manager.

I also need the sequence to enable the high idle feature.

Thanks,
DK

 

I'd be more than happy to help you.....but I'm eight hours away. Calibrating for a larger tire is not a warranty issue and you most likely will be charged for it (generally .5, unless you would start that "five star rating" threat then I'd charge you 1.0 ). Technically we are not supposed to change that info because it's an emisions violation (no I'm not kidding), but it can be done. The best method I've found so far is to road test using a hand held GPS and change the tone ring setting until the desired speed is achieved. I've used the "revs per mile" number, but sometimes the speedo will still be off. GPS allows me to get it "nuts on". .....and while I was in there I'd also enable your "high idle".

 

Alot of the dealers are saying they cannot calibrate the speedo, this seems to be their way of telling you they don't know how.
The speedo change is under the A.B.S. menu, submenu other options, Pinion Factor, Change Revs Per Mile to 601-605, I went 603.
Then it asks to change the Ring Tone, I read to max it out, but I had them put mine in the middle range.
I haven't tested accuracy, but I know its alot closer than where it was, and the truck shifts alot better. I just thought to check my cruise control and make sure that still works, I'll post if there is a problem.
DK

 

Yes alot of techs do not know how, but it's not like they can pick up a book and see how it's done because it isn't in there. Tech line won't help you out on it either because, as I mentioned above, it's not an "approved" change. I grabbed a new truck off the lot and had a "trial and error" session with it one slow saturday until I figured it out.

 

But the TECH line will tell them how to enable the HIGH IDLE.Lots of posts about DEALERS resetting the SPEEDO for a tire size change eaither on this site or TDR.Its been performed a LOT by dealers. Been reading posts about tire size change since the 03s hit the streets.

 

I took it into another dealer today, and they had my high idle active in 3 minutes. They showed me how to use it and told me to get on my way. I said I'll be glad to leave after I pay the bill. They didn't want any part of my money
These 5 star dealers are very good to me.
DK