I have a 98 RAM 2500 with the 5.9L and an automatic OD tranny. My speedo and odometer don't work. The CEL is on with a speed sensor error. It also shifts hard. I pulled up the speed sensor parts at Auto Zone but two were listed, one in the tranny and one in the diff. Which one do I need to replace to get my speedo working? Thanks.

 

wait for more than just my one opinion, but i think its the one in the differential.

 

My vote is for the one in the rear diff. I'm having the same problem with my '99 Ram right now. I looked all over the place and the only place I could find the sensor for the rear dif. was from the dealer. My local dealer wanted $65 I ordered one from chryslerpartsdirect.com for $33 though it was back-ordered for a week, but should be here tomorrow.

I'll post if that doesn't fix my problem but I expect that it will. As I understand it the speed sensor in the trans controls shifting (at least in part) and the speed sensor in the diff controls the speedometer. Though my speedometer still works above 20 MPH along with my cruise control.

--Kevin

 

yeah let me know how that goes for you. I'll probably be ordering one here right quick, probably replacing both of them if the error doesn't clear.

 

its the sensor in the diff.

when the tranny speed sensor goes bad, it'll like to kick out of gear when holding a constant speed and it also likes to stay in neutral when going from a stop.

 

The sensor on the diff won't set a CEL ... just an ABS and BRAKE indication ... as well as random speedo and odo trouble.

When my VSS on the tranny died ... it affected nothing ... just set the CEL.

 

Not to disagree (but I guess I'm going to anyway) on my truck the CEL did come on after I had driven the truck about 250 Miles with the Brake and ABS lights on (not a normal habit for me to drive a car/truck in this condition but I had just left on a weekend trip to the desert hauling my dune buggy when the ABS/Brake lights originally came-on and once I figured-out that mechanically the brakes were fine I decided to keep driving it rather then loose a day of my trip moving everything over to my other P/U).

What was funny is another 150 miles after the CEL came-on my "Check Gauges" light blinked-on once (for maybe a second) and a buzzer chimed. Got home ten miles later, ran the code (with the ABS/Brake lights and CEL lights still illuminated) and got a code of 0500. Un-loaded and parked the truck while I waited on parts. A week later I moved the truck out of my driveway (still had made no repairs) and drove around the block, looked down and the CEL light was gone but the ABS/Brake lights were still there, ran the code again and still got the 0500 code.

FWIW My new VSS just arrived today so I should know in the next couple of days (that's how long it will probably take for me to get around to installing it) whether it takes care of the problem or not. I expect that changing the speed sensor will (at least I hope so, making another desert trip this weekend and would like to be able to drive the truck we bought specifically for trips).

--Kevin

 

Did a bunch of research on this (ran mine with a bad RWSS for 2 months with no CEL) and came across some interesting stuff. Does anyone setting the CEL for the RWSS problem happen to have all wheel ABS?

http://www.turbodieselregister.com/f...ad.php?t=50564

 

Well now I'm confused. The parts I ordered (finally) arrived today so I set about replacing the sensor. Got the old one out and found that either I ordered the wrong part, or they sent me the wrong part. See the photo:

http://i33.photobucket.com/albums/d9...R/100_0700.jpg
This is the part I was sent. The one in my truck (which I didn't get a photo of) is very diffrent; the one I bought seems to be mechanical (meaning the small shaft spins freely) while the one on the truck seems to be inductive.

I'm guessing my truck has rear-wheel only ABS and I must have ordered the part for a truck for four-wheel ABS (Doh!). The part # I ordered was 5013660-AA

http://i33.photobucket.com/albums/d9...R/100_0701.jpg
A shot of the original sensor in the pumpkin.

Any thoughts?

--Kevin

 

It appears that you ordered the transmission VSS for a pre-98 truck. Both speed sensors in newer trucks are hall effect units and send a pulse train to the PCM. That one looks mechanical ... like it needs a gear.