Decent pic of the TCC connector on the side of the tranny?
- Thread starter Trevor
- Start date
G.D. Bryson
New member
Trevor. TCC connector is located on left (driver) side of trans above pan rail, and not real easy to get at, of course. TCC function is also controlled by stop light switch, IE: brakes on, TCC off - you might check it out. Good luck.
White & square 4 contact connector right? Crap...it seemed to be connected pretty well. I still took it off and reinstalled it just to be sure.
Is there more than one brake microswitch? Say....one for the brake lights and one for the TCC (and probably computer). My brake lights work normally.
As a funny side note while I was replacing my leaking OEM waterpump with an Edelbrock I noticed whoever changed the wires last just left the old ones routed through the looms and installed the new ones over them. Freikin' lazy people! :roll:
Is there more than one brake microswitch? Say....one for the brake lights and one for the TCC (and probably computer). My brake lights work normally.
As a funny side note while I was replacing my leaking OEM waterpump with an Edelbrock I noticed whoever changed the wires last just left the old ones routed through the looms and installed the new ones over them. Freikin' lazy people! :roll:
G.D. Bryson
New member
Trevor. Hopefully you are mechanically inclined, or wealthy! HAHA You might purchase GM shop manual series to include Sy/Ty Supplement X-9276 and a quality (Actron, Snap On, etc.) Voltmeter, and educate yourself to care for your truck, or diagnose with a competent mechanic. Sportmachines.com offered a disc with GM shop and parts manuals via djopie@telocity.com. Later you might purchase a scan tool such as Datamaster (tts powersystems.com) or Actron (actron.com). I offer "speak from experience" in that I contracted GM shops (dealers) to work on my '92 Ty while on active duty (U.S.Army): now that I am retired and have time for hobbies I am fixing much of their work. Also, I get volumes of info from the smart guys on this site, and others recommended herein. Good luck with yer truck!
I'm pretty mechanically and electrically inclined. I maintain jet engines for a living so troubleshooting is nothing new to me. 
I've got Diacom so I'm good there. I'm just putting off datalogging until I get alot of the maintenance issues taken care of on the truck.
I looked underneath the dash while I was doing about 10000 other things on truck today. Two brake switches...I'll check them out tomorrow with the multi-meter when I do the other 10000 things on my list. :wink:
I've got Diacom so I'm good there. I'm just putting off datalogging until I get alot of the maintenance issues taken care of on the truck.
I looked underneath the dash while I was doing about 10000 other things on truck today. Two brake switches...I'll check them out tomorrow with the multi-meter when I do the other 10000 things on my list. :wink:
Hmmm...got under the dash and checked the brake switches. The one with the single connector worked fine. On the one with two connectors the black connector receptacle checked fine....the blue connector with grey wires receptacle was a little funky. It showed continuity when the brake wasn't pressed but resistance was alot higher than the other switches. The circuit was completely severed when the brake was pressed (that should be normal).
Only thing that was weird was the resistance for that blue connector w/grey wires receptacle on the dual brake switch. I looked at the TCC connector wires on the tranny again and I couldn't tell for sure but the wires looked like they could be grey.
Datalogged the truck and the ECM is commanding TCC lockup.
Anyone that knows the system give me some pointers? Maybe something else to check?
I don't remember reading about TCC solenoids in the trannys crapping out very often but I don't know what else it is unless it's the wiring itself.
Only thing that was weird was the resistance for that blue connector w/grey wires receptacle on the dual brake switch. I looked at the TCC connector wires on the tranny again and I couldn't tell for sure but the wires looked like they could be grey.
Datalogged the truck and the ECM is commanding TCC lockup.
Anyone that knows the system give me some pointers? Maybe something else to check?
I don't remember reading about TCC solenoids in the trannys crapping out very often but I don't know what else it is unless it's the wiring itself.
jwaller
Evil Genius/SyTy Guru
check here for the pic.
the blue lead does nothing. thats for DRL's.....(not used in our APP, unless your in canada and hook it up yourself )
the 2 red connectors run to a pressure switch. I just usually bypass the switch and put a butt connector on them.
the black one is the case connector.
the solinoid you can usually shake vigerously and if you can hear the check ball rattling then it's fine. if you don't hear it rattle then you need to replace it.
the blue lead does nothing. thats for DRL's.....(not used in our APP, unless your in canada and hook it up yourself
)the 2 red connectors run to a pressure switch. I just usually bypass the switch and put a butt connector on them.
the black one is the case connector.
the solinoid you can usually shake vigerously and if you can hear the check ball rattling then it's fine. if you don't hear it rattle then you need to replace it.
jwaller
Evil Genius/SyTy Guru
Trevor said:
If the cruise works then your brake switch that also controls TCC unlock during a stop is working. you need to try and check the goings on at the case connector and then look inside the pan.
there should only be 2 wires going into the trans. one will have power all the time....
and the other will be the ground that is closed when you command lockup.
check to see if you are geting power at the case connector.
then check to see if your getting ground when you use a paperclip to command lockup via the aldl.
backprobing the case connector would be the only way to do the final check.
if all the checks, check then you either have a bad pressure switch. or a bad solinoid.
and I 've already discussed how to fix those.
Cool...exactly the info I needed.
I'll check the TCC connector at the trans with a multimeter next for power and ground at the ECM harness side.
So the juice goes thru the pressure switch then to the solenoid right? So with no pressure I will probably get an open circuit if I attempt to check the resistance of the solenoid windings thru the connector on the outside of the trans?
No harm from bypassing the pressure switch? I guess there wouldn't be if the control circuit is working as GM intended.
If I've got to drop the pan I need to do a fluid (M1 ATF) and filter swap anyway.
I'll check the TCC connector at the trans with a multimeter next for power and ground at the ECM harness side.
So the juice goes thru the pressure switch then to the solenoid right? So with no pressure I will probably get an open circuit if I attempt to check the resistance of the solenoid windings thru the connector on the outside of the trans?
No harm from bypassing the pressure switch? I guess there wouldn't be if the control circuit is working as GM intended.
If I've got to drop the pan I need to do a fluid (M1 ATF) and filter swap anyway.
jwaller
Evil Genius/SyTy Guru
Trevor said:Cool...exactly the info I needed.
I'll check the TCC connector at the trans with a multimeter next for power and ground at the ECM harness side.
So the juice goes thru the pressure switch then to the solenoid right? So with no pressure I will probably get an open circuit if I attempt to check the resistance of the solenoid windings thru the connector on the outside of the trans?
No harm from bypassing the pressure switch? I guess there wouldn't be if the control circuit is working as GM intended.
If I've got to drop the pan I need to do a fluid (M1 ATF) and filter swap anyway.
the way it works is GM send power to the TCC sol all the time and they activate the sol by closing the ground side. I always bypass the switch, remove it and use a pipe plug. (do this for both of them) this eliminates any and all chance of the switch faling, leaking or messing up in any way.
the trans will not lock the conv in 1st or R. it is impossible. bypass the switch.
the sol usually doesn't go bad per se. so a resistance check will show it's good. if they fail it's BC some junk got caught in the check ball and or passed into the valve and it wont let it operate properly.
I'm screwed. I jumpered the ALDL to command lockup then checked the chassis side of the case connector. Good power and ground. Dropped the tranny pan. Spliced together the pressure switch wires to bypass it. Replaced the TCC solenoid. Replaced the filter. Refilled the tranny. Still no lock up...even with the ALDL jumpered.
I'll say it again...I'm screwed. :-?
I'll say it again...I'm screwed. :-?
Nope...the old one didn't rattle so I thought for sure I had it in the bag but no dice. The truck was bone stock save for a Borla catback when I got it a few weeks ago & since then the converter has never even tried to lock. The truck has a little over 95k on it. The old fluid and filter were damn clean.
I was searching turbobuicks.com last night and I think this pretty much sums up what I'm looking at:
http://www.turbobuick.com/forums/showthread.php?s=&threadid=31083
I'm leaning towards replacing the converter unless someone else has a better idea. Merk posted a few weeks ago that he had a brand new in box stock converter for sale.
I was searching turbobuicks.com last night and I think this pretty much sums up what I'm looking at:
http://www.turbobuick.com/forums/showthread.php?s=&threadid=31083
I'm leaning towards replacing the converter unless someone else has a better idea. Merk posted a few weeks ago that he had a brand new in box stock converter for sale.
jwaller
Evil Genius/SyTy Guru
Trevor said:
if the old one didn't rattle then the conv prob died and sent junkinto the TCC sol. if it did rattle my next question would be do you know for sure it's a locking conv.
but you know it is so now all you have to do is replace it.
good luck and make sure to pull the check ball out of the end of the input shaft when you install your new one.(will make for firmer lockups)