ill be driving down the road and all of a sudden the abs, brake, and service brake system lights will come on. its always been going down the highway. nothing feels different in the brakes and if you turn the truck off and back on the lights go off. all my pads are fine, no leaks, and the master cylinder level is fine. any ideas????

Wheel bearing......... Bad wheel bearing could be tripping the ABS sensor....

Wheel bearing......... Bad wheel bearing could be tripping the ABS sensor....

Check the speed sensor in the transfer case also.

I had the same problem. There are some wires bolted to the frame under the drivers door. Remove, clean and tighten up. Had no issues since.

both wheel bearings replaced 1200miles ago with the lift install, ill try the bolts tomorrow, im out in the field quite a bit so could have got loose and mud got in there, where is the speed sensor on the tcase? wouldnt this throw off the spedo? also its not throwing any codes

Check fluid level and fluid quality in the XFer case.

If the lamp only comes on while driving (not at start up), I strongly suspect you will need to get intimate with how a transfer case is put together.

http://www.dieselplace.com/forum/showthread.php?t=341677&highlight=xfer

fluid was changed in tcase and f&r diffs about 3k miles ago

Really there is a whole slew of reasons you can get the lights and chimes etc on the DIC. The grounding problem is the cheapest problem, wheel sensor problems would more than likely be the second least expensive. If you check the speed sensor on the transfer case( drivers side on the upper part of the case, has a wire connector on it) and find that the end of it has been worn from some internal thingy, then that will be the most expensive fix. When you changed the transfer case fluid was it nice and clean and about 2 quarts drained out. Or it could be the electronic brake control module. Thats about all I can think of .

Light (and chime) only once in motion=

One of the three wheel speed sensors is not sending information correctly.


The integrity of the front wiring can be suspect. Inspect from the wheel bearing to the frame, looking for any compromised wire jacket.

A worn wheel wheel bearing assy (and I mean really worn) can also create the anomaly. With the front wheels off the ground, when a wheel is grabbed and rocked at 12 and 6 O'clock, there should be no movement. A severely worn out wheel bearing will allow the reluctor ring to move farther from the sensor.

Worn bearings in the Xfer case can allow the reluctor ring to move farther from the VSS, resulting in the lamp and chimes. Typically, the speedo will be erratic.

The condition that turns the ABS lamp on will have generated a code which can be scanned and read by some scanners. This code will be very valuable to resolving the condition.

Your tire size comes into play as a factor, too, as with larger tires, the ratio from the front sensors to the rear sensor is altered. Did this problem occur after upsizing the tires? For reasons beyond the scope of this conversation, programming the truck for a tire size larger than 34.5" can also create this problem.

both wheel bearings replaced 1200miles ago with the lift install

it is also not setting any codes to read. i would have a better idea if it threw a code but no CEL comes on and i even stopped and tried to read codes as soon as it happed- nothing.

the lights come on as described but no chime.

the computer is reprogramed for 35in tires and no irratic or problems with the spedo

the computer is reprogramed for 35in tires
You told us your problem right there. Using your programmer, reset the tire size to 34.5" and retry.

I'll find the link later;)

You told us your problem right there. Using your programmer, reset the tire size to 34.5" and retry.

I'll find the link later;)

There's another thing, :) good call. That will be the cheapest fix yet :)

hmmmm thats weird, but ill try it! how far will it throw the spedo off running 35in tires and 34.5in tuning?

Well????

Seriously!? Can no one post the results to a problem when they fix it?

I totally forgot about this thread!!! changed the tire size to 34.5 in my old predator and it never did it again! sorry for the late post, thanks again mccall

Thanks man for the result. I will try it on mine tomorrow and see what happens. My tires aren't that big but they are close so I am hoping that this is the problem and not a bad wire somewhere buried in a harness. I used EFILive to do my tire changes and the problem didn't occur till I changed it for the new tires, although mine doesn't happen all the time which is what makes me worried. Seems to only happen when I push down the throttle while in OD going over 50 so there is a chance it could be my t-case or my tranny. Oh well see what happens tomorrow.

ya could be the speed sensor or wheel bearing like he said also heard of ground problems causing that too. hope this helps. and you better post your results!!

Oh you know I will, that's what it's all about on here.

I tried reflashing my entire ECM with EFILive completely back to the stock program and took it for a drive. Absolutely no change so I am really mad at the thing now. Checked the fluid in the transfer case, it's good. Checked the connectors to the speedo sensor and seem good, pulled sensor and no rub marks. Haven't had a chance to ohm it out yet but there was no visible signs of damage to the harness. Hopefully I am not just limping my tranny.... I did notice that when I give it the gas just enough sometimes I can get the speedo to start to wave at me without tripping the ABS lights or throwing a DTC code so it makes me think it has something to do with that sensor. I hate intermittent problems! :mad:

The ABS code is thrown when the difference between the rear wheel speed sensor and the front wheel speed sensor is approx 5 mph for 5 seconds. The differences between rear and front are in %, so the faster you go the more likely you will throw a code.

Cheers
Cindy

is it 5mph exactally or just 5mph or more for 5sec or more? if so wouldnt it throw an ABS code everytime the rear tires spin more than the front like loss of traction or a burnout?

Found my problem, the red connector on the TCM was not seated, matter of fact when I went to pull the TCM out the plug fell out. I like it when things are fixed for free. :D

Found my problem, the red connector on the TCM was not seated, matter of fact when I went to pull the TCM out the plug fell out. I like it when things are fixed for free. :DAny chance you can post a photo of where this red wire was? Or describe where it is?

Just kinda curious what made you look around the TCM when you had an ABS issue?

Had you missed with the TCM previously?

Glad you fixed it, but as you can guess, I am still looking for my problem. I will pull the wheel bearings and speed sensors pretty soon, my t-case sensor and speed ring looked good according to my trans guy. Wheel speeds sensors ohmed out the same on both sides. .12 @ 20K iirc.