I have a 96 xj with the aw4 that I had rebuilt a year ago. Since the rebuild it has been working great. It has always shifted fine from 1 thru 4 but now the tc is not locking up. I know adjustment of the tv cable won’t help in this instance. Before it would lock up as normal over around 55mph and continue to work fine but it started to unlock randomly. I would be cruising 75 on freeway and with no change on my behalf the rpm’s would shoot up and tc would unlock. Don’t know why.

Other than the tc not locking now at all when the speed is reached it still shifts fine. Fluid is full and still red, not burned but I’m wondering if that could be the factor.

also what should be taken into consideration.

today I just did the torque converter lockup switch diy hoping I could control the torque converter lockup my way and tapped into c14 from the tcu. After hitting the switch and Adding 12v to c14 nothing happened. Does that mean solenoid 3 is bad??

 

While there is always the possibility of an issue with the wiring, the TC Lockup Solenoid would be the most likely culprit...

 

Next time it happens, lift up on the brake pedal with your foot.
Could be as simple as the brake switch out of adjustment. Quite common.

 

Good chance. Did you measure the resistance of the solenoid?

 

Ok so this morning on a quick drive I flipped the lockup switch in 3rd and it did lock. Then an hour later on a quick drive it didn’t lock. And just now it locked at first when I hit the switch in 3rd then shut it off and right back on then it wouldn’t work. I don’t think it’s the brake switch I just put a new one in yesterday. No change.

im gonna go do the ohm test right now on the solenoids connector. I think the tc solenoid might just be petering out already. I would prefer not to drop the pan and all that but.

All signs are pointing to that solenoid or a faulty wire but the wiring looks ok

 

Ok so this morning on a quick drive I flipped the lockup switch in 3rd and it did lock. Then an hour later on a quick drive it didn’t lock. And just now it locked at first when I hit the switch in 3rd then shut it off and right back on then it wouldn’t work. I don’t think it’s the brake switch I just put a new one in yesterday. No change.

im gonna go do the ohm test right now on the solenoids connector. I think the tc solenoid might just be petering out already. I would prefer not to drop the pan and all that but.

All signs are pointing to that solenoid or a faulty wire but the wiring looks ok on

 

mine is in the harness wire to the solenoid, right where it goes thru the rubber plug in the trans, so I have to swap the harness out of my spare trans, which is an annoying job

measure the resistance

I have dropped my pan and swapped and checked the TC solenoid a couple of times