OK...I've replaced the sensor on rear diff. and I've replaced the output speed sensor on the transmission. The speedometer still bounces around until you get up to 20mph and work fine. Once I come to a stop, the speedo shoots up to 120mph. No codes, no ABS light. This is on a 2001 4.7, 45RFE tranny. I'm outa ideas, anyone else got any guesses????
Thanks. Sorry for the thread highjack, the discussion was fresh.

 

try running a test on the instrument panel (hold down the trip button while turning the key to on NOT START) and let us know what happens, the needles should jump around a little bit and be sure to watch the odometer window

also where does the speedo sit with the key off?

btw a new thread for this issue would be the best bet, im sure someone who is able to will make this into one for you

 

When I run the instrument panel test, the speedometer will jump between 0 and 20 while the rest of the gauges make their first move, then goes to 70 while the rest of the gauges are perpendicular and then goes to 120 at the end of the test. the odometer displayed two numbers, 110 and 999.

The speedo will sit differently at times. It's either zero or 120. I have noticed that while at a stop and the speedo sitting on 120, that if I roll forward slightly it will drop back down to zero.
thanks for the help.

I just found the instrument cluster diagnostic codes...110 is a failure in the cluster RAM, CPU or EEPROM. I'm guessing a bad cluster. Any good places to get a new one?

 

you could try and pull one from a junkyard, but no guaranty it will work, im sure ebay has them or that the dealer can get them (i think they need to be programmed with your mileage, im not 100% sure tho)

 

I moved your posts from a DIY to a new thread. The DIY thread he is talking about can be found here: https://dodgeforum.com/forum/1st-gen...ensor-diy.html

 

Then it is still the sensor output. It is either still a bad sensor, badly installed or the wiring feeding it is bad. It is sensor related. That is the only diag for that symptom. You know where the problem is, find the solution to fix it. An ohm meter and a spare sensor may be your best friends.

IndyDurango

 

110.......Replace the faulty Cluster


999......1. Record the faulty message.
2. Depress the trip odometer reset button to continue the self diagnostic test.

https://dodgeforum.com/forum/1st-gen...ml#post2136829


Sounds like a bad cluster. Go to Ebay and buy a new one.

 

Sensors are brand new out of the package....

One bolt and one nut, kinda hard to screw that up.... Checked the wiring for breaks and exposed copper...

Please elaborate more on the spare sensor and ohm meter...

You did read where I'm getting a bad cluster diagnosis error (110)? Still think it's the sensor?
Thanks

 

im in agreement with hydra on this one especially with the code coming up

 

A bad cluster isn't going to provide a code. If anything, it's not going to show a code. That is why I am not in the camp that the solution is a bad cluster.

Again, a speedo that works fine after 20MPH, that's the classic/only symptom for the rear sensor.

not to say you don't have TWO issues, I am just saying...

IndyD