Charlz B.

I changed the solenoid because I had no lock-up, thinking it must be an old part...Not much changed when I was done. I can step on the brakes and the RPM's don't jump up 600 or so, like I've reading about.

I don't think I'm a big dummy about this stuff, but I'm adamant that I got a piece of **** rebuild job when the tranny went on my way from WV to FL. Who knows what parts were put in, but I'm so pissed off that I can't get any madder about this. I have over $2,000 in the rebuild job and warranty, plus parts ex post facto.

Is it possible the TC just was crap from the box? I was told the first one they put in went south immediately, but this one at least lasted 8 months. Someone advise me as to what to do now, please. I'm out of ideas and the limit of my knowledge has been reached.

Charlz B.

Anyone, anyone?

bulletboy29

The ECM is what turns it on. The vehicle has to be up to operating temp and at a certain speed. I think the CTS and VSS play a big part in the operation of the TCC. Mine started working after replacing the ECM and the CTS. Not sure which one got it to working, because I was trying to fix something else!

bulletboy29

Have you tried jumping the terminals on the ECM diagnostic port to make it come on?

Charlz B.

No, not yet. I'll try tonight. I did drive the car 300 miles this weekend and got 19.5 mpg in the highway mountains of WV.

If the port jumping puts the TC into lock-up, then what could be the possible causes that it won't work by itself? Are you suggesting my ECM is going bad?

Thanks for your help.

bulletboy29

I don't think it would be that the ECM is going bad, just a sensor that the ECM uses to gather info for the proper time to turn on the TCC. Try jumping the terminals (I guess you already know which ones) and see what happens.

Charlz B.

I tried yesterday to jump the terminals, it didn't seem to change anything. There was no big drop in RPM, and the car didn't drive any differently. I tried twice jumping the terminals, driving a bit, then pulling the paper clip, and never noticed a great difference. I'll try to find a test light and go through this again, as per Trickster's advice to another member. But right now, I'm at a loss.

Also, when you mentioned the VSS, I don't think my car has VSS. I think it is a year too early, but to be sure, I checked the RPOs and didn't see a D8-.

bulletboy29

I'm lost now...sounds like the TCC could be dead. I was hoping that jumping the terminals was going to make it come on for you. That's as far as my little bit of knowledge goes on this subject. Maybe one of the transmission experts will chime in soon!

How long was that warranty good for?

My TCC is working (knock on wood) and you are still getting better gas mileage than me.

Charlz B.

The warranty was good for 12,000 miles or 12 months whichever came first, but I have had a hell of a time getting anyone to work on it. It's held by ATRA, and I'm starting to think their Golden Rule warranty means that once they have your gold, the rule is to deny and turn everything away.

Thanks for your help bulletboy. Hope I can return the favor sometime.

Anyone else? Jump on in anytime.

bulletboy29

Found this in another thread:

bulletboy29

TTT

Charlz B.

Ok, I may have found the culprit, but I don't understand why. I used a test light on the ALDL port and found that when then brake pedal is pressed down, there is a current between the A & F pins.

Check my method for me. I took a paper clip and put it in the A port, clamped the test light clip to it, put the probe to the F pin, turned the key to ON....no light. Then, pressed the brake pedal, and the light comes on. Isn't this the exact opposite of what should be happening?

If that is indeed a correct diagnosis, why would something that has worked in the past, suddenly reverse it's normal operation?

*EDIT*

I just talked to a tranny shop around town, and got the exact opposite information than I have from the board members. He says that there should be current running to the TC when the brakes are pressed, to tell the TC to unlock. So the test light being on when the brakes are pressed indicates correct operation. I'm bumfuzzled!

Also, I may have asked this earlier....would my car be equipped with VSS? For some reason I think someone said an 87 was a year too early. Doesn't a D8# RPO indicate VSS? If so, I don't have that on my sticker.

I know I have a new CTS and the TPS was cleaned and adjusted about 5 - 6 months ago, because I did these myself.

84406

Any 700R that I have had required power to lock. If there is no power it remains unlocked.

Charlz B.

I'm sure it does need power, but does the power come through the brake switch circuit? I just ask because I think I've been reading the opposite on the boards...that the test light should go out when the pedal is pressed and be on otherwise.

Am I confused?

I read an old post from Trickster about diagnosing a lock-up problem; it says that if the VSS fails, then a convertor won't lock-up at all. I realized that the RPO sheet on by center console lid didn't belong to my car, so I may have VSS after all, I just don't know right now. Is there another place to check RPOs, or how do I check / change the VSS sensor? I have the dealer sheet on my car, but I don't see a D8# on it. Is there another RPO combination that would let me know what I have?

Thanks again everyone.

bulletboy29

Post this under electronics so Trickster can see it or PM Trickster with a link to this thread. He'll tell you the what, when, why, and how this all works.

84406

You said does the power come through the brake switch. For clarity, there is two switches side by side. One is the brake light switch which turns power on to the brake lights and the switch beside it is the converter lock switch that should interupt power when the pedal is pushed. You probably knew that but just in case.

Trickster

Actually 84406, that other switch that you see on the brake pedal is for the cruise control, not the convertor lock. The convertor solenoid is tied into the brake switch though. Here is a schematic of the TCC circuit. CharlzB, if you will send me an e-mail address I will send the rest of the package to you. BTW, your car does have a VSS but it is incorporated into the instrument cluster. The TBI models have a VSS in the transmission and a VSS buffer box by the ECM/

84406

You are so right and thanks for correcting as don't want any wrong info going out.

Charlz B.

Ok, I went out and filled the trans with a lil more fluid after I realized I hadn't put enough back in to start with....oops. I put in three, needed 5 or so. Who knew? Not me....

And a clarification real quick...is the full mark for trans fluid the inside edge of the etched cross hatching or the bend in the dipstick? Just curious, mine seems to indicate it's the bend.

Anyway, I drove around and the transmission works really nicely...it doesn't seem to drag or shift late or anything....except I still don't think it locks-up. No half shift after 4th gear (41mph at light throttle). No rpm jump when lightly tapping the brake pedal in 4th gear.

So, I come home, get the test light out. Put a paper clip in "A" and the probe in F. Key on, no light. Press brake pedal, light comes on.

Take clip from A, insert in F. Probe to A, no light. Step on the brakes, light.

I'd like to disconnect the TCC electrical connector as in the flow chart. Precisely where would I do that? I tried pulling the gages fuse, as I think it must be the source of the TCC electrical current, and connected A to D, no light.

nsimmons

Now my experience was with an 84 vette, but it should be the same. The ecm pulls a certain pin to ground to lock the tcc. Why dont you crawl under the car and find the 4 wire connector running to the trans. With the converter unlocked 2 wires will have 12v. Grounding out one of those wires will force a lockup. This should completley eliminate your car as the problem and isolate it to the trans. You'll have to check which wires i dont remember.

Another option is to pull the ecm, find the pin for tcc and ground it manually. Just stick a pin or needle through the necessary wire and ground it, but doing it right at the trans would be a more foolproof way of checking.

Also lockup cant occur in first, but if you successfully ground the pin and soon as it shifts to second it will lock and when you stab the gas the car will jerk violently due to the locked drive train (like a stick car)

Charlz B.

Just for @h!*s and giggles, I took another test drive....with a paper clip between pins A and F. I noticed something, when I slowed to light or sign, the rpms would drop to about 450-475 before shifting down. But when I took the paper clip out, they would only drop to 600-550 or so.

Maybe I just have a very weak torque converter, and don't know it. Like I've said, I don't know what's inside that transmission now. Before it was rebuilt, it was awesome....it's kinda blah now.


*EDIT*

Question..if the brake switch is open when the brake pedal is pushed, then wouldn't the test light come on when you don't press the pedal? Test light indicates a closed circuit, correct?

My light is coming on when the pedal is pushed...closed circuit. The wiring schematic is wrong or my brake switch is bad, right?

Why do I get the idea I might be heading in the wrong direction?

Someone get back to me quick on that one, please.

Charlz B.

Yep, something's not right on those schematics or I'm completely thinking backwards.

If the brake switch is open when the pedal is depressed, there would be no power to the F ALDL terminal; as there would be no current running through wire 422....right? Therefore, there should be no light when the pedal is pushed.

But the light is on, and that tells me that the circuit is closed when the pedal is pushed. So the switch is mysteriously wired backwards one night, or else it's actually supposed to close when the pedal is pushed.

If I'm confusing anyone out there; at least that's two of us.

Trickster

I'm sitting here looking at the flow chart that I sent you and reading your last post and you have me confused as to what you did. So yeah, I guess there are two of us that are confused. PM me. BTW the connector for the TCC solenoid is on the left side of the tranny going down into the pan. BTW, I take it you got the info I sent you.

nsimmons

This is an over complicated situation. Solution is simple. Run switch from the tcc pin on the ecm to ground. When you want to lock it flip the switch. that will take all of 4 minutes to install.

If that still doesnt work your clutch is shot.

Trickster

Simple solution to you however that isn't the direction that he is trying to go. His problem is a wiring problem.

nsimmons

Have we verified that the tranny is sound and the clutch actually works?

Charlz B.

The car will shift just fine 1-2-3-4, it just will not lock-up. I brought some ramps to work with me today. I'll take a couple minutes at lunch and crawl under the car, see what I see under there. Maybe the plug into the case came undone...who knows.

You know what I want for christmas? A garage that I could rent by the hour. Someplace with a lift, an engine hoist, a tranny lift, air compressor, etc...I forget that insurance regulations would never EVER let something like that happen, but I had a moment of zen thinking about that.

Charlz B.

I crawled under the car and found the plug into the transmission...I unplugged it and found that the plastic is partially broken near where it isolates around each pin. One pin is completely exposed, and there is a separation across the plug itself. I wonder could this be the problem? Does GM sell just a new plug that I could wire on? Anyone know? If so, do you know the part number?

Trickster

While you have that connector off do the portion of the trouble shooting chart I sent you that pertains to that area.

Charlz B.

I went home last night and wired on a new plug harness (got it at NAPA; no one else even knew what I was talking about), as the old on looked like it had seen it's last trip. Drove to Lowe's, didn't really get above 55 mph, but the rpms seem more in line with what they were before this episode started.

Came to work this morning, got to pay some more attention, and I think there just must have been bad connections at the tranny case. I hope this is the end of it.

Trickster, thanks for all your help on this. My car and I are ever grateful.

Trickster

tom3

Pretty simple to test for sure. Drive on level road about 60, give it a little gas and watch tach. RPM should remain really constant, no revving up. Some autos have pressure switches inside the tranny wired in series with the TC circuit, these can go bad too. Hope you did get it fixed with the connector, easy to overlook the simple things for sure.