Speedometer not working have questions

[Piper Cavender]

I just bought a 2002 Jeep Liberty and the speedometer, odometer and cruise control just went out and the engine light came on saying the speed sensor is bad. We already changed the speed sensor on the transmission but it didn’t work. So my question is did I change the wrong speed sensor?? I found a post that says I need to change the speed sensor on the rear differential to fix the speedometer, not the transmission sensor. Anyone know the answer to this. The cluster is fine I did the self test on it and it passed.

 

[LibertyTC]

The rear diff speed sensor has been problematic to many KJ owners.
The diff sensor wires / connector should be inspected and consider a new Mopar diff sensor.
I siliconed the wires going into the connector and then used some split loom tubing over top of the wires.
Luckily my sensor & wiring has been problem free on my 04,touch wood..

 

[Piper Cavender]

I’m hoping that when I change the differential sensor that it fixes everything. I can’t afford an expensive fix. Thank you for your advice.

 

[Billwill]

My 2002 Export CRD had the speedometer stop working when fairly new. Found that the connector to the sensor on the rear diff was making bad connection.

I fixed the connector and speedo started working fine but CEL light stayed ON for about two weeks and then went out after a fair amount of start/stop driving. Been working fine since then.

A lot of owners have had problems with the wiring to the sensor rubbing through on the Park Brake cables or elsewhere chaffing to chassis.

One owner removed the sensor and found metal particles on the sensor end....not good news regarding the state of the diff