Bad TCC solenoid?

[streetknight]

Got a stock GN I'm working on and took it on it's maiden voyage today. It seems as if the converter is locking right when it goes into 2nd gear or shortly after, around 20 MPH, part throttle or WOT doesn't seem to matter. I'm getting some knock retard too that I'm leaning toward this causing.

Anyway, someone told me to ease it down the road and after the converter locks to keep accelerating (easily) and tap the brake pedal and it should make the converter unlock. It doesn't.

What should I check, solenoid or could it be the converter itself?

TIA

 

[azbob]

Disconnect the electrical connection on the drivers side of the transmission...then drive the car. If the problem goes away you have a bad solenoid.

 

[streetknight]

Thanks, I'll give it a try.

 

[SSedan64]

Some TCC Solenoid Info & Pics>> TH200-4R TCC Solenoid Transmission Problem

 

[TurboBuRick]

That's a nice write up.

 

[Black6]

you have a bad tcc solenoid

 

[streetknight]

Yes it is guys, thanks. Finally had time to unplug the harness and drive it and it drives like a dream.

Thanks again.

 

[turb0buick57]

Theirs a couple past post saying dont drive around with it unplugged too long or you will overheat it. Make sure you replace the solenoid soon.

 

[streetknight]

Ok guys, I want to make sure of this. I didn't really want to fool with changing the solenoid. I called my local tranny shop that's always done all my transmissions. Told him what I'd found. He said that if I unplugged the harness and the converter didn't lock at all, that is was NOT the solenoid. He said it sounded like it was a computer or wiring issue and it sounded like it was getting a signal to lock the converter all the time.

What do you guys think?

 

[turb0buick57]

TCC_Lockup

Check out the TCC article posted in post #4 and this one from vortexbuicks. Ultimately you can go through the troubleshooting steps before pulling the pan. If the wiring doesnt check out you have a place to start. If it does check out then I would still change the TCC, its 2 bolts and 2 wires and only takes a few minutes after pulling the trans filter.

But as far as your guy saying if you unplug the trans electrical connector and it does not lock, then its NOT the solenoid, if you do a search in this section you will find a whole lot of post that disagree.

 

[streetknight]

Thanks, I had read post #4. It looks like most have the issue of it not locking at all. But, I'll test everything and see what happens.

Thanks again

 

[turbofrank]

I drove my car about 6mo with wire disconnected cruise rpm a little higher. I just missed OD if you know what i mean.

 

[turb0buick57]

Thanks, I had read post #4. It looks like most have the issue of it not locking at all. But, I'll test everything and see what happens.

Thanks again

Forgot to add, if you have a scantool other than scanmaster, I believe it will tell you when the ecm is attempting to command lockup. Verified that on turbolink a few times cruising.

 

[SSedan64]

I drove my car about 6mo with wire disconnected cruise rpm a little higher. I just missed OD if you know what i mean.

Unplugging the Trans connector cuts power to the TCC Lockup Solenoid. You would still have 4th/OD, the TCC just wont lock & cause a slightly higher engine 150-200rpm or so at cruise speed. I'm not sure what else it wil affect, such as Timing etc..

May have more Info:
http://www.turbobuick.com/forums/transmission-talk/250799-what-signals-should-i-have-trans-plug.html and TCC operation>> http://www.turbobuick.com/forums/transmission-talk/260404-lockup-solenoid-tutorial.html

 

[SSedan64]

Ok guys, I want to make sure of this. I didn't really want to fool with changing the solenoid. I called my local tranny shop that's always done all my transmissions. Told him what I'd found. He said that if I unplugged the harness and the converter didn't lock at all, that is was NOT the solenoid. He said it sounded like it was a computer or wiring issue and it sounded like it was getting a signal to lock the converter all the time.

What do you guys think?

If the Trans connector is unplugged the TCC should not engage. If it does there's a problem in the Pump, cross leak, the TCC Apply Valve sticking/binding or TCC damaged.