1998 Dakota, 5 speed manual, 4 cylinder. Looks like I have the AX15 tranny on board. Where is the speed sensor located?!?! I can still not find it. Everything points to driver side rearwards. But I checked both sides. Only wiring I found is the backup light switch located at the passenger side. Here's a pic or two. Is it the black cylinder? Then they may have given me the wrong part

 

On the top of the rear axle its inserted into the differential

 

I already replaced that sensor, I get P0500 output vehicle speed sensor.
Speedometer still doesn't work. I have the torque pro obd monitoring app and indeed I get no signal at all.

So I guess I'll be be checking voltage to the terminals of the rear diff sensor plug next

 

I checked the plug for voltage (key in on position) and I got no voltage. Is the plug supposed to supply electricity to the sensor? Or just receives signal from the sensor?

 

I would like to see if anyone can share a way of testing the sensor plug. Continuity/resistance test didn't really get me anywhere and voltage is 0 with key to on position.

I don't know how to test this one, I need some guidance, please

In case I need to check for broken wires, I found that the sensor plug feeds into the PCM at pin 27. All 3 plugs in the PCM have a pin 27. Which one would it be?

Thanks

 

No power is supplied to the speed sensor. It generates a small ac voltage when the tone ring passes by.

You'd need an oscilloscope to test functionality. An ohmmeter can test for continuity.

Pin 27, Connector 2 at the PCM.

 

This was a suggestion by me that worked for someone that had ABS problems same sensor so you may want to check it out.

Pull the diff cover dumping all the oil clean out with brake cleaner as good as you can install cover fill with the cheapest oil you can find drive for 3 months remove cover again clean again you may be surprised how much dirt is now in the bottom of the diff.

One note about this I dont know how well this works on a limited slip diff only on an open diff setup and an 8.25 rear end I don't know if it works on a 9.25 rear end.

All his ABS problems cleared up doing this

 

Daaaaaang that's a clean differential case! Mine leaks a bit so I was planning to do that anyway, along with checking driveshaft alignment.
Next weekend sounds promising

So your rationale is that from the dirt and crud the magnet is not picking up the gears?

 

Yes the dirty oil is messing things up you could have to much metal dust suspended in the oil.

By the way if you have the 8.25 rear and still the OEM cover its a known fact the fill hole was positioned too low. So either replace it with a good after-market cover or what I did was fill it then jack the passenger side up and poor in a little more oil be sure the plug is a new tight plug or it will leak out.

If you plan on trying the cheap oil in the diff for 3 months tip/trick only use a gasket no rtv so you don't need to scrape rtv off now the second final time use the rtv and a gasket.