hey guys im having a problem. i have the abs and break lites stuck on. and the dtc says to service break system soon.; what could be the problem? my breaks work fine but my abs dosent work. i have a 2003 chevy 2500 hd dmax with a quad 215 tunner and running 285/16 coud the tire size cause this? break fluid is full. abd break pads and roters look new. ond i have no play in the wheel bearings. any help would be great.

 

You should get the codes read.

It could be the front wheel speed sensor(s) have moisture or rust build up.

There is a reflash out there for the Service Brake System message but it usually doesn't accompany warning lights.

Check to make sure you EBCM is plugged in securely. (driver's frame rail, just behind driver's seat)

Could be a corroded ground. Driver's side, front body mount- you'll see two or three wires held on to the body mount just to the left of where the parking brake cable passes through. Remove that bolt and throw it out! Scrape off all the frame coating and clean the ring terminals. Then use a new bolt with a lock nut to reattach the wires to the body mount. Coat the mount with some rust proofing.

Get the codes.

 

funny, i have the same problem right now

 

i had that same problem with the abs & (!) (P)
brake
light on. turns out the abs modulator valve was bad. I think there is a relay for it in the under hood electronic center. the valve at least on my truck was located on the on the driver side frame rail. If this the problem and you take it to a shop to have it done you will spend a fortune having it fixed. But when mine went out me and my dad fixed it. If I can recall correctly the valve USED was around $300-$400. that should be the problem. for the time being you will just have regular brakes. If you do deiced to do it your self let it gravity bleed over night and bleed the regular system out like crazy. That should do the trick. oh wheel and tire size shouldn't have any thing to do with it. Neither should the tuner.

 

kewl thanks guys im hoping it is just somthing simple and cheep but i doubt it.

 

pulled my code out after i replaced the ground bolt. its a P1781

I think gonna have to scan it with the laptop

 

I kept having that poblem with PPE Hot+2 Tuner. In the Recalibation dept I had to reset the Wheel Diameter back to the stock dia. Are you running stock tune? There was a thread about this on another site I used to be on.

On edit I see you got a tuner - Sounds familiar to problem I had

 

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.

But ive ran my tire calibration much higher than before than what i have it now. I think it may have to do with the wire i messed with int he ECM, kinda fiddled them them a bit when i was installing high idle

 

Any updates on this problem?

 

none as of yet still on and going to bite the bullet and take it to the steeler next week and get a reflash and see if that fixes it or they can pin pont it for me. hope it wont break the bank wish me luck. is their an more ideas out their?