AW4 Unlocking/Locking TC

After picking this thing up in January (check sig) and tracking down a bad AW4 (started a thread a while back), I ripped it out and replaced it with the AW4 out of my old '91 2-dr w/ 240,000 on it.

So here's the dilemma...when my right tire goes over a series of pretty good sized bumps at any speed with the TC locked up, it unlocks it and then locks it back up again.

If it does it enough, I get a Check Engine light with a "TPS high voltage" reading, or OBD-I code 24.

I inspected and cleaned both body and engine grounds, cleaned up the terminals on the battery and cleaned the connectors at the firewall heading down to the transmission, the TPS is new, and I replaced the ground strap with about a 4-6 gauge battery wire.

The only difference I could think of between the two years is the Power/Comfort switch, but I would've thought the TCU bypassed this in '92?

Oh I also thought that since I put in a DD brake booster that maybe the brake pedal wasn't contacting the brake switch over serious bumps, however I don't think it would throw a code?

Thanks for your help in advance guys.

Any advice here? Not sure what to do.

I think I might swap out the TCU and start playing with running some new "test" wires to see if there's a short...

the only thing i could think of would be to check to make sure that the brake pedal is not contacting the switch when u hit the bumps, and make sure that on the plug ins that the pins have not pulled away from the plug i remember reading a thread on here where someone had a wire pull loose from the plug there is a couple of threads about locking the tc up manually, that should help with what wires to chec good luck

Just an update, I plugged in another brake switch that I know works and the problem persists. I know that the pedal is pushing the plunger on the switch far enough in that the pedal would have to wiggle very far away to not make contact with it (there is very little movement in the pedal without putting force into it).

Possible NSS issue? I'm going to check the voltage at the ground and see what I'm getting.

Take readings off the TPS.....they can be funny monkeys, even if you replaced it.

Got a buddy with the same vintage XJ as you?? Borrow his TPS....see what happens.

Will do thanks guys.

Update...

Bad TPS, swapped in a known working one and all is better!

Thanks guys!