Speedo problems

USPLibby · **Joined:** Thu Jul 28, 2005 12:29 am **Posts:** 372

I have a weird on and off problem with my Speedometer. I already have changed the sensor on the diff and the wire socket going to it and this problem seems to come and go with a big change in the weather. It acted up before just before the hot weather but went away. Now the weather is getting cool and the speedo is freaking out again.

Is there another area where this wire can get pinched? Last time the wire wore thin right at the socket.

Or is there another sensor somewhere that can effect the performance of the speedometer/transmission?

My transmission over drive shifts like crap when the speedo acts up. Turning off the overdrive fixes the bad/hard shifting.

lacabrera · **Posted:** Thu Aug 25, 2016 9:21 am

USPLibby wrote:

I have a weird on and off problem with my Speedometer. I already have changed the sensor on the diff and the wire socket going to it and this problem seems to come and go with a big change in the weather. It acted up before just before the hot weather but went away. Now the weather is getting cool and the speedo is freaking out again.

Is there another area where this wire can get pinched? Last time the wire wore thin right at the socket.

Or is there another sensor somewhere that can effect the performance of the speedometer/transmission?

My transmission over drive shifts like crap when the speedo acts up. Turning off the overdrive fixes the bad/hard shifting.

Had the same issue with mine, turned out to be a damaged front right ABS sensor wire on the wiring loom just before the connector. Seem to remember rear sensor controls odometer reading and front right sensor MPH.
Mine was very intermittent.

USPLibby · **Joined:** Thu Jul 28, 2005 12:29 am **Posts:** 372

lacabrera wrote:

USPLibby wrote:

I have a weird on and off problem with my Speedometer. I already have changed the sensor on the diff and the wire socket going to it and this problem seems to come and go with a big change in the weather. It acted up before just before the hot weather but went away. Now the weather is getting cool and the speedo is freaking out again.

Is there another area where this wire can get pinched? Last time the wire wore thin right at the socket.

Or is there another sensor somewhere that can effect the performance of the speedometer/transmission?

My transmission over drive shifts like crap when the speedo acts up. Turning off the overdrive fixes the bad/hard shifting.

Had the same issue with mine, turned out to be a damaged front right ABS sensor wire on the wiring loom just before the connector. Seem to remember rear sensor controls odometer reading and front right sensor MPH.
Mine was very intermittent.

My Liberty doesn't have ABS. The problem went away again. It's a really weird problem.

jeepingpatton · **Joined:** Mon Aug 22, 2016 6:54 pm **Posts:** 24

[quote="USPLibby"
My transmission over drive shifts like crap when the speedo acts up. Turning off the overdrive fixes the bad/hard shifting.[/quote]

I was gonna say the wire might be damaged further up......until I saw this. When my speedo sensor fell out (most likely stolen because the screw was still in place and wire harness was tied up) my speedo wouldn't work and it threw a speedo code. But it shifted fine and drove great. So im stumped

Billwill · **Posted:** Sun Aug 28, 2016 4:33 am

USPLibby wrote:

lacabrera wrote:

USPLibby wrote:

I have a weird on and off problem with my Speedometer. I already have changed the sensor on the diff and the wire socket going to it and this problem seems to come and go with a big change in the weather. It acted up before just before the hot weather but went away. Now the weather is getting cool and the speedo is freaking out again.

Is there another area where this wire can get pinched? Last time the wire wore thin right at the socket.

Or is there another sensor somewhere that can effect the performance of the speedometer/transmission?

My transmission over drive shifts like crap when the speedo acts up. Turning off the overdrive fixes the bad/hard shifting.

Had the same issue with mine, turned out to be a damaged front right ABS sensor wire on the wiring loom just before the connector. Seem to remember rear sensor controls odometer reading and front right sensor MPH.
Mine was very intermittent.

My Liberty doesn't have ABS. The problem went away again. It's a really weird problem.

Yeah the 2002 KJ without ABS only uses the sensor on the rear diff for speedometer.
You would have to trace the leads all the way from the sensor plug...first check the contacts inside the plug are good and clean...all the way to the BCM. I know some owners have had this lead fraying on the cables for the park brake.

Did you replace the sensor with an OEM Mopar product?
I know that all 2005 KJs have a TSP that the wrong diff oil may have been put in the rear diff at the factory....this oil chews up the sensor. Fix is to have the Dealers drain and clean the rear diff, fill diff correctly and install new sensor. I know this does not apply to your model KJ but what oil do you have in your rear diff?

USPLibby · **Joined:** Thu Jul 28, 2005 12:29 am **Posts:** 372

I'll have to find the receipt but I think it was a real Mopar sensor. I had the fluid changed around June, I think it is just regular gear oil. I've been using regular heavy gear fluid ever since I read that the synth can cause early wear on the pinion bearings. "I had to rebuild and replace the pinion/carrier bearings around 61k, using full synth from the beginning and serviced at the dealer regularly" :banghead:

ATXKJ · **Posted:** Mon Aug 29, 2016 7:52 pm

I changed the sensor - didn't fix the problem

changed the connector and about 4" of wire - and everything worked

the old wire did not look or feel damaged

Billwill · **Posted:** Tue Aug 30, 2016 3:11 am

ATXKJ wrote:

I changed the sensor - didn't fix the problem

changed the connector and about 4" of wire - and everything worked

the old wire did not look or feel damaged

Weird....but glad it is fixed. I had a bad connection on the diff sensor on my 2002 Export Manual CRD....CEL came on and speedo would only go up to about 30 mph. After fixing the bad connection the speedo worked fine but CEL stayed ON for about two weeks before going out!

Speedo problems

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