I'm tuning on an 04 4x4 with 315/75/16's and a 3.73 rear. The stock setting on the tire was 29.something, I changed it to 35 to correct the speedo, but now it's throwing the Service Brake System message. I checked Nitto's site and they said the tire's actually 34.5, so I changed it to that hoping that's what it was, no luck.

Anyone else had this problem? What was it and what fixed it?

It's kinda wierd cause it will do it when you turn the key on, you turn the ignition back off and back on and everything's OK. Run the truck a little more, kill it, next startup, the Service Brake message is back.

 

I get 34.6" when I do the metric conversion. I doubt 0.1" will make a difference though. Was it throwing the code with the stock 29" setting? I say try putting it back to stock, and see what happens. Check the wheel sensors too, although I doubt they were damaged.

Oh yeah, does the ABS light come on at all, or just the SES light?

 

There are no 'codes thrown' but the ABS light and the brake light come on. The wires were checked that go to the wheel sensor.

No, it wasn't doing it before hand.

 

mine started throwing a code like that after i changed my gears. it comes and goes just like his truck...

 

Have you done anything to fix it or attempt to fix it?

 

no i haven't fixed it yet, i believe someone said that the dealership can fix it. i need to have it fixed before my warranty goes out, lol

 

I dont think you can affect anything to do with the brakes
with tuning
sounds like it was going to happen anyways

maybe something with the larger tires and the wheel sensors
overworking the ebcm

Heres some interesting reading
they fixed mine
http://www.modulemaster.com/gmabsrepair.html