let's beat this horse....speedometer issues.

[JeepCoMJ]

02 jeep liberty, 3.7 auto 4x4. 120k miles.

There's no other issues than this.

Speedometer only "works" when not accelerating/not on the gas. At this point, it bounces around.

Under acceleration, it cuts out altogether, down to zero. This is under any acceleration conditions.

Having done a cluster test, everything performs just dandy on the cluster. The cluster had been out recently to replace all of the lights, so I double checked the connector.

The transmission shifts perfectly. There are zero issues with ****** shift points...so I assume it's got nothing to do with the ****** sensors.

Also leading to that assumption...zero CEL, zero codes with a snap-on pro scanner.

My conclusion is that the differential speed sensor must have issues. It cannot be the tone ring, because there are no noises...and that would sound something awful if it were to come off the carrier.

It *could* be the sensor.
The connector looks fine, no corrosion on the pins.

I haven't ohmed it out, and the ground is wet, shop is full, and I'm not crawling under it to check the wires. I am willing to accept that there are likely issues with the wiring harness to it. I cannot believe the crappy design of putting the sensor in the diff.


With 123000 miles on it, in WI, I'm betting that it's the wire...but could be the sensor.

Any other advice? I'll get it in the shop soon as I can.

 

[yellocoyote]

I would check for compromised wiring leading up to the speed sensor at the rear diff (its happened to me twice). If that looks good, then I would look at replacing the sensor.

 

[JeepCoMJ]

Well, I have not actually dug into the wiring, but having unplugged it and plugging it back in, it still functioned intermittently.

After doing so, I gave the harness a tug, knowing that any compromised wire would seperate completely as a result. Confirmed it's the harness and not the sensor by doing so...now I do indeed have a CEL and no speedometer.

This is good news to me. I ordered the new pigtail (comes with a good amount of harness) for $23 from the dealer (normal price at $29).

I'll finish it up tomorrow and take pictures as well as post the part number. This will become a how-to.

 

[JeepCoMJ]

part number is 5013995AA


List is $29.25, but you can get them to go down to $23.95 at the dealership.


comes with two pre-pinned blue wires, one new connector, two 2" sections of shrink wrap, 4 crimps (brass solderable).

I'll post pics when I fix it this weekend.

 

[tommudd]

Another one of those little things I check/clean/spray at every oil change
just general maintenance that these things need

 

[JeepCoMJ]

I can see why, obviously. What I can't comprehend is why on earth you'd put the sensor there instead of on the transfercase like everything that actually makes sense.

 

[mightybeet]

having similar issue. i removed the bolt and was spinning it around but couldnt get it out. does the speed senor in the differential come straight up and out or does it twist out? ...though the spinning of the sensor seemed to fix what ever is causing the intermittent speedometer drop for now.

also... i hate these connector clips with the red lock.

 

[uss2defiant]

21.72
from avondale wholesale but you'll have to wait since it'll be shipped to you.
shipping is typically free

Jeep Parts - Avondale Wholesale Parts

 

[tommudd]

having similar issue. i removed the bolt and was spinning it around but couldnt get it out. does the speed senor in the differential come straight up and out or does it twist out? ...though the spinning of the sensor seemed to fix what ever is causing the intermittent speedometer drop for now.

also... i hate these connector clips with the red lock.

Pulls straight up out.
You moving it changed the position of the wires is all , still need to replace

 

[mightybeet]

does the speed sensor feed the odometer as well?

 

[tommudd]

does the speed sensor feed the odometer as well?

Yes

 

[mightybeet]

ah... hence the reason it looks like my mpg went down.

 

[mightybeet]

well its not the speed sensor cause problem came back. ordered new harness.

does the differential speed sensor also talk to the transmission along with the transmission speed sensor?