Hi folks,
I've been reading a bunch of threads about this for the past hour or so.
Seems generally it's the rear speed sensor. I've also seen it called the rear ABS/speed sensor. I've got a 2000 Dakota R/T 5.9 rwd automatic.
Not sure where to start. I could just replace that relatively inexpensive part, but I never saw what the part number was, specifically for my model. I suppose that it could be something else too. Do most folks just replace that sensor first without even running any troubleshooting? Guess I want to know the non-dealer start to finish smart debug method.
I checked p codes and it says "p done", so I assume that means no p codes.
Is there some other codes that can be read by Autozone? I saw a note about that they would read your error codes for free to see which part is bad.
I saw this part - http://www.partsgeek.com/catalog/200...ed_sensor.html
and wondered first if it's the correct part and second whether anyone else has bought it and thinks Dorman is a good product.
Thanks for any suggestions.

 

Hi Jeff,

Since it's an RT, do you have 4 wheel ABS?

The catch here is the red brake light. Something else is going on. The red light usually indicates a problem with the base brake system - not the ABS portion. This could be the parking brake is on (or the switch is tripped) or you have a difference in pressure between the front and rear brakes and have tripped the combination switch. From the factory manual is in italics: The red brake warning lamp is used to alert the driver of a hydraulic fault or that the parking brake is applied.

And it gets more complicated: If an ABS component exhibits a fault the CAB will illuminate the ABS warning lamp and register a trouble code in the microprocessor. The lamp is controlled by the CAB. The CAB controls the lamp sending a message to the instrument cluster.
If red warning lamp is illuminate with the amber warning lamp, this may indicate a electronic brake distribution fault.
The red warning lamp will illuminate if an ABS component exhibits a fault and the amber lamp is burned out.

I'm curious about the CAB (Controller, Anti-Lock Brake). If supplies the speedo signal to the instrument cluster and can account for both lights.

There are two fuses for the CAB. A 40 amp (Fuse 8) in the PDC under the hood and a 15 amp (Fuse 3) in the junction block by the drivers door. Check both. Pull them, see if anything changes.

Brake codes can't be read by most scanners. A dealer can read them with their DRB and test all the components.

 

Its the rear diff speed sensor, been there done that, abs and brake light on, speedo not working or not working till 25-25mph. Idk why the lights come on, I think it has to do with the ABS going off the speed sensor and the brake light being a companion light for problems.

 

Hi Dan,
I don't know if I have 4 wheel abs. I checked the parking brake as soon as I saw the error lights and it was off. I even stopped the truck and put the parking brake on and off and nothing changed.

 

Hi Greg,
the differential speed sensor is the most common answer for sure. I think I'll call autozone and see if their scanner will read the brake codes and take it from there. I do coincidentally have $45 worth of autozone coupons, so I could buy the speed sensor and not take a hit just to try that.

Thanks for your input.

 

Usually it throws a code though, P0500.

 

I didn't see a code. I did the ignition on off 3 times and it said "p done".
I called Dodge just now and they say the rear differential speed censor is about $45.
However, I spoke with a Jr and supposedly also Sr member of the service team and both say they there's no speed censor on top of the rear differential of my 2000 Dakota RT.
Seems read that ten times on this forum. Do I have it wrong or are they nuts?

 

They're nuts. I bet if you brought it in they'd find it.

Look for yourself. Right along the top, just follow the harness.

 

Sensor is on the top passenger side of the rear diff and looks like this. Get a new one, replace the old one and ALL your problems will magically disappear.

 

I ordered one from Autozone. Actually they had to just transfer it across town.
Supposed to be in yesterday. Hopefully will be today.
Thanks again.