95 auto problem AW4?

[jeepinandy]

I have a 95 cherokee sport 4LHO auto I assume it is the AW4 tranny NP231 transfer case... I stopped at a red light today, when I went to pull out It seemed to be stuck in over drive. I pulled it down into 1-2 and it took off fine. It shifted on it's own from 1 into 2 then I put it up into over drive I couldnt tell if it went from 3 into over drive or straight to over drive. when I got up to speed and started up a incline It wouldnt shift down on it's own. when I got home, I stopped on a hill near my home put it into OD and pulled out there was no changing gears. but reverse is fine and 1-2 is fine fluid is full and not burnt. but it does have a brown tint. any help appreciated
-Andy

[jeepinandy]

anyone?

[JJacobs]

Make sure your brake switch is applying 12V when the pedal is pushed down. I believe there's two switches at the pedal and both should have 12V on each wire.

Also take a look in the manual for the specs and test your TPS. Backprobe the connector so you don't open the circuit.

[jeepsrock]

check the basics first.
1. transmission fluid level /color
2. tps sensor
3. all fuses related to tranny
4. proper kickdown cable adjustment
5. brake pedal button

pete

[Panama XJ]

I had same problem with my XJ 95 a couple of years ago, was a selenoid in the valve body, very expensive for a selenoid but very easy to change.

[jeepinandy]

found out to be shift solenoid in the tranny..... thanks guys

[jeepsrock]

how did you find out out of curiosity ?

pete

[byu_xj]

I second that pete. How did you find out that the solenoid was bad? because I have the exact same symptoms on my 95? Additionally can the tps on a 95 be adjusted? I believe that that answer is no but I have not found out for certain.

Steve

[Panama XJ]

TPS isn´t adjustable, you can check resistance at the connector for each selenoid, in my case they read OK when cold and open when became hot.

[byu_xj]

So what your saying is that the solenoid should always have a certain level or resistance for proper operating condition. However, when your transmission got hot then your solenoid stopped working correctly or the circut became open (no resistance).

This sounds like the proplem that I am currently having. The jeep opperates normally for about 5 minutes of city driving but will stop down shifting when it finally gets warmed up. I thought that the temp could be effecting the TPS.

Can you describe for me in more detail the process of checking if a solenoid is working properly?

Thanks

Steve

[WobblesXJ]

If you do a search there's a great tech page on here. You can either pull the pan and check each solenoid or check it from the computer. On a 95 I believe the trans computer is integrated into the ECU so checking them at the pan woudl be easiest. Just pull the pan and each solenoid should have one wire to it, pull that wire off and check for resistance fromt he spade connector to the case of the solenoid. If there's no resistance then it's open and you need a new one.

[WobblesXJ]

should be like 13-17 ohms I believe. Practically a short. What you're really reading is the coil in the solenoid.

[Panama XJ]

As Wobbles said, selenoids are coils, in my case when the selenoid was hot the expansion of the core opened the circuit at the cracked wire, when it became cold the core compress the coil and it had continuity again.