2004 lly dmax

[bman]

So just got my truck tuned and the abs and e barke light are coming on and say service break system after start up drive for about 1 mile and it comes on also the tuner did my tire size said they were 34 inch and now my speed is fast by about 5-7 mph also hard shifts around the 75 HP tune

[THEFERMANATOR]

Sounds like he over corrected your tire size. Some trucks do not like having the tire size corrected beyond a 35" tall tire, so if your speedo is fast he probably set it for to tall of a tire. And if a tune shifts hard, most likely the torque tables need adjusting.

[bman]

Ok would u no anything about that abs and ebrake light and it saying service brake system

[bman]

Is this true
i heard that on efi live if you calibrate the tires 15% over stock it will set the abs/brake light to go off since the speed sensor on the front tires detect them they are off the actual speed on the speedometer.

[bman]

And when I have it on any thing besides stock when it shifts it drops about 400 to 500 rpms on stock it dose none

[Mitco39]

When you calibrate the speedo with efi live it does not let the abs controller know what is going on. It just so happens that when you approach 35" tires there starts to be to big of a missmatch between what the abs sees for speed and what the ecm sees for speed and a fault is triggered because the abs controller knows something is wrong its just not sure what.

If your only dealing with the ecm tune then the only thing that changes your shifts is the throttle position, if you map your throttle table then the throttle position relative to the amount of power being produced is thrown out of wack thus changing your shifts.

[rgullett83]

Find someone with a tech 2 and have them change the tire size in the ebcm to the tallest size available, and that should alleviate the abs light

[killerbee]

So just got my truck tuned and the abs and e barke light are coming on and say service break system after start up drive for about 1 mile and it comes on also the tuner did my tire size said they were 34 inch and now my speed is fast by about 5-7 mph also hard shifts around the 75 HP tune

Find someone who knows what they are doing. These are novice errors.

[bman]

He has been doing tunes for a while a lot of your big diesel shops use him idk I don't get way it drops some much in rmp through shifts

[THEFERMANATOR]

And when I have it on any thing besides stock when it shifts it drops about 400 to 500 rpms on stock it dose none
Changing the speedo has ZERO affect on the TCM. The TCM shifts and works directly based off of the output speed sensor in the transfer case for 4X4's, or the transmission for 2X4's. The TCM then sends a speed sensor signal to the ECM. So unless your tuner is committing the sin of altering the speed tables in the TCM without doing ALL of the other tables, changing the speedo has NO effect on shift points and RPM drop.