Got a 2002 Dodge Dakota 4.7 and all of a sudden the abs and brake light on dash come on. Brakes are fine parking brake works and is not stuck,then noticed the speedo doesn't work and the cruise also doesn't work. Checked the fuses fine, brake fluid fine, and disconnected the battery for about 10 min thinking it might clear but it didn't. Ok guys where to look for the problem I'm not that good on the modern stuff so I really need some help. Probably simple to some. I really appreciate al the help I can get. Thks Garymac

check the abs module. they're known for having bad connectors, that get water inside them, and cause all sorts of mischief. the rear axle speed sensor could also be bad. it's about five hundred bucks cheaper than the abs module (located behind the battery)

the speed sensor would signal the speedo, cruise, etc. the abs problem might be solved by opening, cleaning, lubing and reconnecting the abs module.

Doubt its the module. Likely the RWSS or the wiring that goes to it.

Well somebody help me, what is the RWSS and where is it located? I know I sound very dumb and I am when it comes to newer elec problems. It is so funny drove about 250 miles yesterday and no problems then this morning all crap broke out. Thank you guys for taking the time to try and help this old mopar man.

If you spot a wire harness going into a sensor in upper differential, that may be clipped to brake hose or diff vent hose, that sensor would be suspect.

Well, found a harness and plug-in at the rear differential unplugged it and cleaned it with electronic cleaner spray but still doesn't work. Can I buy a scanner that will scan for the problems? Or do I have to take it to a dodge dealer so they can do it? Thks for helping guys I'll keep plugging along. Oh also noticed that the auto door locks when moving do not work so I guess that is also hooked up to all of this. Gary Mac

yes, the locks get a signal at 15mph (from the speed sensor) and lock. if you cleaned the connection, and it doesnt work, you need to test it, and/or replace it. the sensor is about 50 bucks. chasing the wires, all the way to the ecu, is free for you to do, though. pull apart each connector along the way, and clean out, spray with tuner cleaner, etc.

i'm doing the front abs sensors on my '02 pt cruiser this week. they are bad, and the abs light, brake light and trac light all came on. tested the computer, and it's throwing codes for the front l/r abs sensors. get a scanning tool, and have at it.

Well here is what happened today, as I said earlier tried to clean the connection above the rear end. Still no luck so I thought I would look at the front brakes and there were no connections or wires there so that settled that. I started reading my Chilton's manual and a part I must of missed (due to being OLD) it talked about this truck just having rear abs and a flow valve etc. Then it talked about a ABS hyd controller located on the frt left fender close to the brake fluid reservoir and it showed a pic. Yup I tried to get the connector to unplug and even the little safety latches broke and I couldn't tell if there was one underneath or not. But I sprayed elec cleaner in there as best as I could but it still didn't work. I sprayed some more and tapped on the controller a few times with a screwdriver and lo and behold it cleared itself. As of tonight it is still working and we will see what happens tomorrow. You guys are awesome helping to diagnose problems like this. Thanks a lot guys and we will see what happens. Gary Mac

On a RWAL system esp with a posi the sensor can get damaged from a broken posi. The retainer clips break and cause damage to the sensor. FYI

Your truck came standard with RWAL. 4-wheel ABS was an option. Which system do you have? Post a pic of your inner fender if you don't know which system you have.

That said, the symptoms you described is spot on for a faulty speed sensor located in the top of the rear differential. It's about $20 at your local parts store and probably in stock.

If you wanted to pull the codes first to 'troubleshoot' the problem, the dealer has the scan tool to access the abs codes. The scanners used at parts stores can only read emissions codes. But the dealer will want $100 just to plug in the scan tool.

Well after cleaning the rwal sensor and cleaning the controller on the left front fender it is still working fine. Don't know if it was dirt or water but if it happens again I think I will know where to go to troubleshoot this. Thanks Gary Mac