Input/output speed sensors

Hey everybody. I have a 2001 Jeep Cherokee 60th anniversary edition with a 4.0L I6-AW4 transmission. I keep getting a P0720 code which has had me troubleshooting lately. In order for me to get acquainted with the trans, I made a point to read up about it in the transmission diagnostic procedures manual from chrysler, on this forum and some others but I have become confused as to how many speed sensors I am supposed to have. The information I have read point to 2 (in/output). All I've got under there is the output in the rear of the trans and the VSS plumbed into the transfer case output. I'm not seeing the ISS anywhere. I read today that an in/output was placed in there from years 98 to 01 making me think the trans was swapped out with an older models. Does anyone out there know exactly how many sensors I should have in my model? If not having the input there, what problems will that cause? Thanks in advance for your help!
Matt

You should two blue/green speed sensors on the 1998-2001 transmission.
One on the front and one on the rear (behind the transfer case shifter bracket).

P0720 Symptoms
- Check Engine Light ON
- Speedometer improper reading
- Possible shifting problems


This my be useful - http://www.naxja.org/forum/showthread.php?t=1053970

.

Hey man, thanks for the quick response and the link! I believe most of my shifting problems are due to something internally. I checked the output sensor circuit the last night found slightly high resistance in the sensor ground to TCM connector. Cleaned the connections and the TCM to body ground which lowered resistance, cleared the code but it came back. I am starting to suspect the valve body because in the mornings:
1) No reverse gear
2) 1-2 shift doesn't occur unless I throttle off a little or at around 3-4000 RPM's (I've adjusted the TV cable too.)

After it warms up the trans shift fine, reverse gear returns, would you think maybe I could rebuild/replace the valve body? Anything else I should be checking? Thanks in advance for your time!

Matt

I am looking for the part number on the 2 blue output sensors front and rear in that picture above.

Sounds more like a solenoid/TCU/NSS and/or electrical issue than the VB.
Don't bother with aftermarket solenoids, they are crap. Oe if your local dealer has then, or JY/used trans.

blondejoncherokee said:

I am looking for the part number on the 2 blue output sensors front and rear in that picture above.

Click to expand...

Mopar part number is 4897734AA.

Rockauto has them.

http://www.rockauto.com/en/partsearch/?partnum=4897734AA&a=Referer+www.bing.com+URL+/

thanks. I just wanted to verify that the front and rear are the same part #, and that they are indeed the right ones for my 1998. This is good to verify that .

I ended up getting the Standard motor products version -SC121 - for 33$ + overnight shipping from Amazon . I might have to eventually go to Mopar if these standard are junk but I am trying to diagnose a bad tranny leak and the front sensor seems to be seeping really good upon cleaning the tranny really good.