TCC won't lock

[kjhansen]

I know this has been beat to death in various forms, but here it is again. Let me get specific though.
1. I hardwired a TCC lock-up switch into the car years ago. It has always worked (if the TCC would lock up. I've burned a few out).
2. The torque convertor is a Precision Vigilante 5-clutch. The TCC locked fine, then the car sat for almost a year.
3. The car is back on the road, but the TCC doesn't lock anymore.
4. I checked the switch on the brake pedal and it seemed OK, but that's basically an unlock switch anyway, isn't it?
5. I pulled the TCC solenoid, and it clicked when I put power (12V) to it--at least the first few times. Then it shorted out or something and is now dead. Oops. Should have tested it once and left it alone. Bottom line was that it was OK and the TCC didn't lock anyway.
6. I bought a generic replacement part. Looks weird, but the parts store tells me it's what's called for in all TH200-4Rs. It replaces the two bolts with studs and the stud nuts push the solenoid tube down just about 3/16". But the tube part is just that much longer, so it should fit OK. You have to cut the wires and re-attach them with the included plastic locking nuts. Anybody have any experience with these replacement solenoids?
7. Is there a trouble-shooting tree for this problem? Seems like that if the solenoid is OK and the clutches are OK, there must be something else (OK, I'm assuming that in a 1-year old Vigilante the clutches are still OK).
Thanks.
Keith

 

[kjhansen]

Hello transmission guys. Nobody has replied to my e-mail above yet, but I have another question to add.
If the two wires that go into and out of the TCC lock-up solenoid are just tied together (i.e., the solenoid bypassed), will the TCC lock up or does it require something else? I mean, there is that tube with the O-ring on it that goes up inside the trans. It must do something, right?
Keith

 

[Real-T]

Keith,

I think by tying the wires together it will do nothing. The solenoid needs 12v and a ground in order to activate and that is what those wires connect too.

It seems also you are doing everything correctly but given that you have an updated/longer solenoid and the body of it is larger than the one it replaces.

Sometimes what happens is that when re-installing the pan, it may be difficult to go on and if you hit the solenoid body, sometimes it will cause it to bend and maybe even crack the shaft.

The crack will cause the solenoid to leak an then no lock-up.

Also be absolutly sure that there is 12v and ground on the two wires on the transmission connector when the switch is activated.

Just a thought, if everything else checks out, pull the solenoid again and see if it is OK and while you are there make sure 12v is seen
across the wires inside the trans too..

 

[mikestertwo]

First of all, you have to be careful on which way you apply the 12 volts to the solenoid. There is a diode across it so polarity is important. If you apply the voltage backwards, you will most likely blow the diode, which then they usually short. Second, do not short the two wires together. There is 12v on one wire and you will just blow the fuse when you turn your switch on or if the computer commands the solenoid to lock, you could fry the driver in the computer. Third, the solenoid only goes on in one direction. It has a slight offset in it and the pan will be difficult to get on if it is put in backwards.

 

[kjhansen]

Thanks for the answers guys. I appreciate the help. Fortunately I put a drain pan plug on the trans (as close to the back of the deeper part as I could--clears the filter and all), so pulling it doesn't require a Dexron shampoo anymore .
Keith

 

[kjhansen]

Well, new TCC solenoid and new 4th gear pressure switch. Still no TCC lockup. Can't force it with the ALDL port A-F connection either. Now what?
Keith

 

[mikestertwo]

First, check to see if you have 12v on pin "F" of the ALDL connector. If you don't, check pin "A" on the connector on the transmission. If you have 12v at the "A" connector, the problem is either in the wiring inside the trans or a break in the wiring from pin "D" on the trans connector back to the computer. If you don't have 12v on pin "A" of the transmission, your problem is either a misadjusted/bad brake switch, broken wire between the brake switch and the transmission connector, or a blown fuse/wiring problem between brake switch and fuse box.

 

[kjhansen]

It's fixed, but I still have questions
I was running connectivity and continuity tests on the wires from the connector to the computer... reconnected the harness to the transmission and I had the key on and the lockup switch switched. I heard a click. Uh-oh. So I wiggled the connection some more and heard it click some more. Yep. Loose connection on the side of the trans. The little plastic retainer dohickey on the trans side was broken off so the plug from the harness just kind of sat there. I tightened it down (don't ask), and now it works. I had 12v inside and out when testing with the trans apart, but when driving, it wiggled around enough that the connection was lost.

Moral of the story: Always check the simple things first.

On the other hand, I did learn how to switch out a TCC solenoid and did put a drain plug on the trans pan, something I've been meaning to do for a long time.

Question: Why do I have 12v at the light-blue wire? It's the 4th gear pressure switch signal. This is 12V COMING FROM the car into the trans. I thought this was an outgoing line. The green/white wire (which is the 3rd gear signal wire) doesn't have 12v coming in. In any case, the car automatically goes into TCC lock-up at highway speeds like it's supposed to and unlocks when you tap the brakes. No question about it when the Vigilante's 5 clutches lock up! The 4th gear and TCC lines work in TurboLink also, but 3rd gear doesn't. It shows that the car is ALWAYS in 3rd gear.
Keith

 

[TurboDave]

It's fixed, but I still have questions
I was running connectivity and continuity tests on the wires from the connector to the computer... reconnected the harness to the transmission and I had the key on and the lockup switch switched. I heard a click. Uh-oh. So I wiggled the connection some more and heard it click some more. Yep. Loose connection on the side of the trans. The little plastic retainer dohickey on the trans side was broken off so the plug from the harness just kind of sat there. I tightened it down (don't ask), and now it works. I had 12v inside and out when testing with the trans apart, but when driving, it wiggled around enough that the connection was lost.

Moral of the story: Always check the simple things first.

On the other hand, I did learn how to switch out a TCC solenoid and did put a drain plug on the trans pan, something I've been meaning to do for a long time.

Question: Why do I have 12v at the light-blue wire? It's the 4th gear pressure switch signal. This is 12V COMING FROM the car into the trans. I thought this was an outgoing line. The green/white wire (which is the 3rd gear signal wire) doesn't have 12v coming in. In any case, the car automatically goes into TCC lock-up at highway speeds like it's supposed to and unlocks when you tap the brakes. No question about it when the Vigilante's 5 clutches lock up! The 4th gear and TCC lines work in TurboLink also, but 3rd gear doesn't. It shows that the car is ALWAYS in 3rd gear.
Keith

To address your question. The reason there's 12v on the 4th gear wire is that's what's supplied by the ECM. When 4th gear is engaged that line is then grounded and the ECM now knows you're in 4th gear.
The 3rd gear line might just be floating. Don't know why, maybe a bad switch in the tranny, maybe a bad connection anywhere between the ECM and the switch.
The active signal on those wires is "ground" supplied by the tranny switches to the ECM.

 

[kjhansen]

Hmm. I'll have to try and track down that 12v source wire for the 3rd gear switch--just in case I ever get my BRF trans back. The one in the car is a 30G (1984 Olds TH200-4R) that was swapped in sometime by someone--who exactly, and why, remains unknown. All parties are denying responsibility. For know I'm making do with the 30G. It doesn't have a pin on the connector into the transmission for the 3rd gear switch... Still, there should be 12v at the plug from the ECM I would think.
Keith