No Converter Lock-up.

[HighMileage]

Hey gang..

I bought my '87 GN with 80k mi less than a month ago. Thanks to this Group,I'm working the bugs out. Next bug....

As far as I know,the 200R4 is a 4spd with lock-up. If so,I'm not getting lock-up. Otherwise,the tranny works great,imho. The harder I step on the gaz,the more firm the shifts. But,rpms are about 3,000(factory tach)at 55mph.

Also..the Cruise doesn't work. I remember these can be related by the brake pedal switch. The Cruise light does light,however,and goes out when pedal is depressed. So,I'm not leaning towards the switch.

I rebuilt a GX3 (3.33 final) 440T4 for one of my A-bodies in '03 as part of a 3-to-4spd swap. So,I have a little tranny knowledge. But it's been awhile. The swap is perfect to this day.

Isn't there a way to check the TCC electrics thru the ALDL connector thru A or B terminal? Looking for a testlight to light when TCC engages?

Eventually I'll be dropping the pan and changing fluid/filter,as I have no idea if this has ever been done. Fluid looks,smells ok.

Any input appreciated. Thanks.

Steve from Upstate,NY. '87 GN t-tops. ...an 8 1/2 out of 10. Mostly stock.

 

[mikestertwo]

Isn't there a way to check the TCC electrics thru the ALDL connector thru A or B terminal? Looking for a testlight to light when TCC engages?

Steve from Upstate,NY. '87 GN t-tops. ...an 8 1/2 out of 10. Mostly stock.

Terminal "F" is the converter signal. Connect it to terminal "A" (ground) to lock the converter.

 

[HighMileage]

Terminal "F" is the converter signal. Connect it to terminal "A" (ground) to lock the converter.

Had a few hours to drive/fix the car tonite.

I ran a wire out of A,and another out of F. (top left and top right) With the car fully warmed up,I touched the wires together once in 4th,with very little throttle pressure.

....nothing.... No converter lock-up.

I'll have to get my test-light and see if I am at least getting power from "F". Maybe it's just a bad TCC solenoid. ? If so,at least it stuck off,and not on.

Any more ideas?

Thanks.

Steve from Albany,NY. '87 GN,t-tops. Mostly stock. ..unless the prev owner did something I don't know about.

 

[notacarlo]

Check the fuse labeled "ECM/solenoid on the panel.

 

[HighMileage]

Check the fuse labeled "ECM/solenoid on the panel.

I don't see that one. I see ECM/IGN,but that's not it...

Hard to believe that my '87 GN wasn't built with it.

Is there a link to a fuse panel pic you could send. I searched,and searched here for a pic.

I *really* need to find a Factory Service Manual for this car! All of my other GM's,I have one. <frustrating>

Steve '87 GN.

 

[notacarlo]

I believe it is in the top right side of the panel by your left foot. If that blows....no lockup.

 

[HighMileage]

I believe it is in the top right side of the panel by your left foot. If that blows....no lockup.

I found it up there. It's all the way on the top right,as you indicated.

The fuse (10-amp) looked and tested good. I cleaned the tips with sandpaper and reinstalled. Started the car,let run for 10 mins....

Road test time: 1...2...3...4..(now at 55 with light throttle pressure)...no lock-up. I touched A and F together (still light throttle pressure)...no lock-up. Then used a testlight from F to ground. No light.

Where to go next?

Is there a TCC plug on the tranny,like the 440T4? I can check for continuity between there and ECM.

I'm still wondering if my non-working Cruise is related to this. Cruise light lights,then goes out with the brake. So,it can't be the switch..?

Thanks for your input.

Steve from Albany,NY. '87 GN,t-tops. <--having that old Chapman alarm removed tomorrow.

 

[mikestertwo]

I'm still wondering if my non-working Cruise is related to this. Cruise light lights,then goes out with the brake. So,it can't be the switch..?

Thanks for your input.

Steve from Albany,NY. '87 GN,t-tops. <--having that old Chapman alarm removed tomorrow.

Still can be the brake switch. The cruise uses a different switch.

 

[HighMileage]

Still can be the brake switch. The cruise uses a different switch.

The cruise must use that one farther up the pedal,with the vac line on it.

My brake lights work ok. Are there 2 circuits in that switch?

Idea: A conversion to vac brakes was done recently by prev owner. I see plugs unplugged near the master cyl. They had to be for the powermaster. Maybe something needs to be jumped there for the TCC.

Gee. Maybe this now belongs in the electrical discussion...

 

[mikestertwo]

My brake lights work ok. Are there 2 circuits in that switch?
..

Yes, there are 2 circuits on the switch. You should have 2 connectors. One is for the brake lights, the other for the tcc lockup. There is nothing on the powermaster that has anything to do with the tcc.

 

[HighMileage]

Yes, there are 2 circuits on the switch. You should have 2 connectors. One is for the brake lights, the other for the tcc lockup. There is nothing on the powermaster that has anything to do with the tcc.

Checked the TCC portion of the brake light switch with an ohm-meter. Circuit is closed with brake pedal at rest. Open with pedal depressed.

To recap:

1)ECM/Solenoid fuse ok.
2)No signal from "F" on the ALDL when in 4th with light throttle pressure.

Not sure where to go from here besides finding a wiring schematic and tracing wires. I know there are tan wires involved in this. I *do* have an '87 Celebrity Factory Service Manual. But how much is in common,I'm not sure.

I wonder if someone installed a chip that eliminated the TCC signal... Possible ECM failure?

I'm all for testing and not throwing parts at this.

Steve. '87 GN. t-tops. Mostly stock.

 

[mikestertwo]

Checked the TCC portion of the brake light switch with an ohm-meter. Circuit is closed with brake pedal at rest. Open with pedal depressed.

To recap:

1)ECM/Solenoid fuse ok.
2)No signal from "F" on the ALDL when in 4th with light throttle pressure.

Not sure where to go from here besides finding a wiring schematic and tracing wires. I know there are tan wires involved in this. I *do* have an '87 Celebrity Factory Service Manual. But how much is in common,I'm not sure.

I wonder if someone installed a chip that eliminated the TCC signal... Possible ECM failure?

I'm all for testing and not throwing parts at this.

Steve. '87 GN. t-tops. Mostly stock.

The problem is not the ECM or chip. All the ECM does is ground the TCC, pin "D" on the trans connector. The way to troubleshoot this problem is with a volt meter. With key on, check voltage on pin "F" of the ALDL connector. If there is no voltage backtrack. Check for voltage on pin "A" on the trans connector. If you have voltage on pin "A" of the trans connector and nothing on "F" of the ALDL then the problem is either in the trans or wiring between connector "D" on the trans and the ALDL/computer. If there is no voltage on pin "A" of the trans connector backup to the brake switch and make sure there is voltage on pin "B" (PNK/BLK wire) on the switch. If not, blown "ECM/SOL fuse. If you do have voltage there the problem is either the switch or wiring between "A" on the brake switch (Purple wire) and "A" on the trans connector. It goes through connector C100 pin H6.

 

[HighMileage]

The problem is not the ECM or chip. All the ECM does is ground the TCC, pin "D" on the trans connector. The way to troubleshoot this problem is with a volt meter. With key on, check voltage on pin "F" of the ALDL connector. If there is no voltage backtrack. Check for voltage on pin "A" on the trans connector. If you have voltage on pin "A" of the trans connector and nothing on "F" of the ALDL then the problem is either in the trans or wiring between connector "D" on the trans and the ALDL/computer. If there is no voltage on pin "A" of the trans connector backup to the brake switch and make sure there is voltage on pin "B" (PNK/BLK wire) on the switch. If not, blown "ECM/SOL fuse. If you do have voltage there the problem is either the switch or wiring between "A" on the brake switch (Purple wire) and "A" on the trans connector. It goes through connector C100 pin H6.

I appreciate your help on this.

To run thru the process: There is no 12V at the ALDL-F.

I have no idea what "pin A" is on the trans connector. I'm guessing it is the purple or tan. I unplugged the connector and got nothing at either. The inside of that plug is super-clean.

Now the brake switch... That pk/blk you mention is on that switch that is above the brake light switch,higher up the pedal. It's the switch with the large vacuum line going to it. Now...I *thought* that was the Cruise Control switch. However,the pk/blk mentioned goes to that. I have 12V there.

I removed the switch and checked continuity of that switch. It was intermittent with switch depressed. (plunger in) Beeping wasn't solid on my ohm-meter.

I took the switch apart. That grease in there created sort of a varnish in the contacts. Cleaned with elect cleaner,sanded connections,retested. Beeping is solid now.

Switch is back in. I ran out of time on my short schedule of free time.

No idea what/where C100 pin H6 is.

I know I desperately need an FSM (no Chiltons,Haynes,etc)for this car. Looking.

More tomorrow.

Steve. '87 GN,t-tops. Mostly stock. Waiting for Powerlogger. All probs have to be worked out before mods for speed begin.

 

[mikestertwo]

The pnk/blk wire does go to the cruise vacuum release switch. I get the non cruise and cruise control cars backwards sometime. Old age creeping in From the brake switch the wire (purple) goes through connector C100 pin H6 (that is the connector on the back of the fuse panel) to "A" on the trans connector (also purple). If you have voltage at pin "B" (pnk/blk) on the brake switch and nothing on pin "A" (purple wire) at the trans connector the problem has to be the brake switch or a bad connection at H6 on C100 at the back of the fuse block.

 

[Mudweizer]

I need 4 posts to post the diagram.

 

[Mudweizer]

2

 

[Mudweizer]

3

 

[Mudweizer]

4

 

[Mudweizer]

See if this diagram helps:

 

[mikestertwo]

Here's the diagram you need