Theking

Hi all!

Thank god I found this forum. Bought an Jeep Grand Cherokee 1999 Limited Edition with Quadra-Trac II. Love that 4.7 V8.. Awesome machine..

Been using it for 1½ years as a daily driver car. Runs so smooth and fine. until yesterday. While driving around 80-90 km/h (approx 49-55mph).
It suddenly shifted and I felt really felt the gear change, either from 3 to 4 or a downshift from 4 to 3.. Engine and tranny had just been running for like 5mins and the outside temp was around 0 Deg celcius (approx 32 Farenheit).. slowed down and accelerated smootly and it changed fine again. stopped and fuelled her up and rolled out again. then suddenly the Service Engine was on and the the engine was at ~2500rpm at 80km/h (usually its around 1550-1600rpm at that speed) so it seems like its not shifting in to 4th and the O/D on/off button wont help it change or anything.

So I turned the key on/off on/off on/off 3 times and got the following code:

F0700: looked it up and turns out like this: EATX Controller DTC error (found on this page)


Today I picked up and ODBII reader and got these 2 codes:

F0715: Input/Turbine Speed Sensor "A" Circuit (http://www.dtcsearch.com/P0715/)

F0731: Gear 1 Incorrect Ratio (http://www.dtcsearch.com/P0715/)


Car runs good in 1,2,3 and R and all that dont think it puts in the 4th gear thou (cause it runs at 2500rpm at 80 and normally around 1550-1600rpm at that speed). and the gears are put in with and little "clunk/hard" not as smooth as it used to have done.

Tranny have runned awesome and never had any strange shifting or anything, Oil looks and smells as it should. Red and clear, correct level. Never had any noises or anything so is it as simple as electrical/relay problem or is it worse?? could'nt be right?

So my question is, Where to start with this error? Never had any problems with it. Never worked on a Jeep 1999 before (only Camaros 3rd gens..)

So I hope you would take some time and read thru this and help me out, would really make my day.

Thanks For your time!

Dan Norberg, Sweden

Theking

Been reading around some, seems like a common failure on these transmissions.
input/output sensors going bad. could it be that simple for me to?

A bad sensor causing the P0715 (found this thred on another forum: http://www.jeepforum.com/forum/f13/r...-p0700-112286/) he had the same codes P0700, P0715+ P0731+732+733 I only have the P0715+P0731 (not the 2nd and 3rd as he had.)

He changed out his sensor and the problem was solved. Is there a way of measuring the senor (ohm) or should I just buy a new one and replace it?

Any thoughts or suggestions is really welcome, Id appriate all help I can get.

Also how do I know wich sensor I need ? Where there 2 types of transmission during this time?
one with 1 sensor and another with 2 sensors, is there a way of knowing wich one I have without crawling under the car? no garage and pitch black outside so I would love not to raise it if I dont have to..

Found a "manual / how to" for this error here : http://www.wjjeeps.com/speed_sensors.htm

How do I know wich sensor to order?


Thanks again, hopefully someone could help me out here,