My 99 3500 CTD is suffering from the abs light/brake light problem. From searching, I have heard everyone say to check or replace the speed sensor, but I can't find any instructions on how to do so. Is there how-to somewhere or could anyone post the procedure? Thanks in advance

Mike

 

The speed sensor is on the rear diff, above the drive shaft. Unplug the wire and remove the bolt on the sensor clamp. You may have to twist or pry sensor out. Takes about 10-15 minutes. I think the one I bought was $25-$35. Hope this helps!

 

Hint- clean the surfaces around the speed sensor thoroughly before removal, you wouldn't want to have sand in your differential

 

Thanks guys!!

Now when I get it out, is there anyway to check it to see if it's gone bad or not? Like with a multimeter or something?

Thanks again

Mike

 

Don't know but it fixed mine. Brake light and ABS light stayed on , on the dash. About a month later the spedo would not move till about 20 mph, and it would not shift out of first until spedo jumped up. Changed it out and was good as new.

 

Is this the same part to replace to correct for over-sized tires? I run 285's and my speedo is off by 10% or thereabouts.

 

No, that just sends the revs of the axle to the computer which then feeds the speedometer/odometer.

You have to interrupt that signal and replace with one that fits the actual rev's per mile.

There are a couple boxes that do this, Superlift Truespeed and the Abbot ERA.
I have the Truespeed and it works great, kinda spendy but I think the ERA is as well.
Truespeed has a switch to switch between different sizes, fer instance, if you run snow tires in the winter, road tires in the summer, and they are different sizes.

You could also try having your PCM reprogrammed with the correct rev's per mile, but getting the Dealership to do it, of finding one that knows how is a chore.


phox

 

have the same problem and tryed the replace with new sensor,,,,,didn't work,,,,lites still on,,,,,thinking maybe i have to actually let a dealership scan it to see,,,,any other ideas???,,,,,tryed scanning it myself with an aftermarket scanner and it didn't have any antilock brake date in it at all,,,was told Chrysler did so to keep that to themselves,,,,,anyways,,,,,any help is appreciated,,,,,

 

My Abs and Brake light(as many may know) had been on for like 2 months. I replacd the drums, which were too thin, Saturday and that took care of the problem. All in all, I replaced the rear speed sensor, calipers, master cylinder, and proportioning valve. Trying numerous times with a computer to scan it and not figuring it out. The best thing to do first is to adjust rear shoes and see if they are even hitting the drum at all. I will admit I thought the braking was good, but now with brand new Wagner drums from O'Rielly Auto Parts, ($65 a piece), I can't figure out if it has 4 wheel disc or not!!! Have a blessed evening everyone.