CamaroKid89RS

iTrader: (1)

I thought I had a '95 LT1 with transmission and computer. Well recently I discovered when I hooked a laptop up to my PCM and did a VIN check it has the code for a '94. I hooked the laptop up because I was attempting to diagnose a problem with my TCC not locking up. The engine runs fine, the transmission shifts into every gear, but the TCC just won't lock up. I tried wiring the TCC lockup wire to a switch that when activated goes to ground, but nothing happens. How can I tell what year the engine and trans are? The stamps on the block and transmission casing? Is it possible that I could have a bad lockup solenoid? I'm totally lost guys.

Coach Hawk

More than likley the brake switch is bad. It's a much more common problem than a bad lockup solinoid. On your scvanner, one of the data points should be "TCC Brake switch" or something along those lines. It should rear "open/closed" or "on/off" Make sure is changes when you press the brake

CamaroKid89RS

iTrader: (1)

If my brake switch was bad, wouldn't my brake lights not work? Also the TCC won't lock up as in it never locks. I understand that it unlocks when you press the brake, but does the brake switch have anything to do with it locking?

Coach Hawk

There are two switches on the brake pedal, one operates the brake lights/cruise deactivate, the other controls the TCC unlock. I checked my '94 LT1 today, on my scanner it says "TCC Brk Swch" and is normally "off". When you step on the brake, it goes to "on." Check to be sure yours does the same thing. If the switch is bad, the converter will NEVER lock. I had the switch go bad on my '91, took me awhile to figure out. I thought it was my old stock ECM, but even when I swapped in the LT1 PCM, it still wouldn't lock the converter. That meant it was a chassis wiring problem, not an ecm problem.

CamaroKid89RS

iTrader: (1)

Interesting, I didn't know that switch was separate from the brake light switch. The car was a manual before, and I just have the TCC lockup wiring tied in with the brake lights. Is the brake switch for the TCC lockup part of the same switch for cruise control, or is it a different switch entirely?

CamaroKid89RS

iTrader: (1)

Ok here's what I did. I totally separated the torque converter wire from any computer inputs and wired the lockup to a switch. Ran one side of the switch to the torque converter lockup solenoid, the other side to ground. When I flipped the switch absolutely nothing happens. Does this mean that my solenoid is bad?

Coach Hawk

I think you need to run power to the solenoid, not ground. maybe someone can can verify that?

CamaroKid89RS

iTrader: (1)

I tried running ign power to the solenoid, and ground, nothing.

Coach Hawk

Time to pull the pan then. You should be able to remove the solenid and jump it with clip leads to a battery. If it works, you should be able to hear it click on and off.

CamaroKid89RS

iTrader: (1)

Ok, I dropped the pan, tested the solenoid and heard it click so it must not be that. I don't have a TCC cutout switch on the brake pedal, my engine came with a custom wiring harness from Ron Francis (a company), which says to wire one to the wire that has 12V when the brake is depressed, and the other 3 go to the computer, with a relay installed. I think that when the brake pedal is pressed the power is taken away from the relay which is activated by the brake lights, however I will go and check this out as soon as I can get someone to help me. Plug D pin 11 shows 12V when ignition is on, which it's supposed to, and the voltage is .6 when I reach a certain speed. Would that be enough to make the solenoid not be grounded, or would that be ok? I guess I need a laptop to hook up and physically see what the computer is seeing because I am totally stumped; or perhaps absolutely retarded if it is locking up and I just wasn't noticing it.

Edit: One wire always has 12V when the key is on and the other one doesn't when the brake pedal is pressed, but when it isn't pressed it has 12V too. This function I believe serves the same purpose as a TCC cancel switch.

CamaroKid89RS

iTrader: (1)

Ok here's what I have found out. Pin 11 plug D shows 8.2 Mega ohms when the torque converter should be locked (highway speed). When I am going slow (when the torque converter should be unlocked, I get OL [infinite ohms]). What could be causing this, bad ground?

CamaroKid89RS

iTrader: (1)

Bad program perhaps?

Coach Hawk

Beyond my knowledge at this point.