im actually having the same issue, would the brake switch be behind the pedal? if so would replacing it be better or could a hit with some contact cleaner be good?

 

Unplug the brake light switch and go for a quick ride and see if the TC locks up.

 

it is behind the pedal, tho.

 

No, it connected to it at the top. 2 wires. Blue/white, and pink

 

I think if the switch was stuck on your brake light would be on 24/7, but there are two separate switches in one I think...

 

I'm not sure about that myself. It's just a simple way to determine if the brake switch is in the equation.

 

Factors in AW4 shifting include TPS, VSS, TCU, NSS, brake pedal switch, and that Comfort/power switch.

Have you checked the resistance on your S3 solenoid (and S1, S2)cold and hot?

Put your comfort/power switch in power and forget it, or rewire to power and eliminate the switch.

Some of the more recent trans threads dealt with TC lockup or lack of, and a couple have been the result of a dirty NSS, or an adjustment was needed for better contact in the NSS.

My '96 didn't lockup properly when the S1 shift solenoid was bad, but works fine now that its been replaced. It made no sense to me, but I'm just reporting my observation.

If you want the AW4 manual and AW4 diagnosis manuals in pdf, PM me your email address.

 

Another random thought. Over near the trans dipstick tube are 2 rather large connectors, one gray and one black. They carry signals from TCU to trans and vice versa. I pulled mine apart and they had corrosion. Sprayed them both out with contact cleaner and added dielectric grease before plugging them back in. Solved an intermittent shifting problen on my wife's XJ. Couldn't hurt.......

 

The black 8 pin is for the NSS, and the grey 7 pin is for the trans/TCU.

Check for continuity in the NSS connector going to the trans. Check for resistance of solenoids through the female connector of the 7 pin.

 

Yes, the brake light switch has four wires going to it.
I assume one side is for the trans, what was the vss?

 

VSS is the vehicle speed sensor. Its on the tail shaft of the trans on the LH side. It will have a 3 wire connector, and is held in place by a single 10mm bolt. In 1998 the AW4 got a 2nd VSS in another location.

 

Sorry to pirate your post but Im having very similar problems with me 97 XJ. It unlocks in OD as soon as you let off the gas and will not relock until you park it for the night. I have replaced all solenoids, fluid and filter, TPS and TCM. If my problem was related to one of the listed sensors wouldnt I have CEL stating which sensor was at fault?

 

Not necessarily. When my S1 was going bad and finally quit working, it NEVER threw a code.

 

Dont worry about it, the more info the better.
Ok so I unhooked the brake light switch with no changes though I did only unhook one side so the brake lights still worked was that not correct?
I also checked the NSS and the other plug by the trans dipstick no corrosion but I am not sure how I would go about testing those.

 

PM me your email address and I'll send the manuals as attachments.