Loss of Torque Converter Clutch (TCC) Lockup - 1994 Regal - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Buick When starting new posts, please specify YEAR, MAKE, MODEL, ENGINE type, and whatever modifications you have made.

Reply
 
 
 
Thread Tools Search this Thread
Old 09-01-2015, 11:19 PM   #1
Senior Member
True Car Nut
Thread Starter
 
rjolly87's Avatar
 
Join Date: Jun 2003
Location: Las Cruces, NM
Posts: 6,857
Thanked 298 Times in 246 Posts
rjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant future
Default Loss of Torque Converter Clutch (TCC) Lockup - 1994 Regal

I should probably hold of on starting up a thread on this because I am not ready to dive in to this, but oh well.

I was driving to work in the Regal this morning when I noticed the tachometer riding a bit higher than usual. I start fiddling with the controls, and found the RPMs were moving around with minor adjustments to the throttle, instead of engine speed being directly locked to vehicle speed. An engine restart at speed yielded no change, and the problem was still present on the trip home later in the day.

Forum experience suggests wonky TPS and Brake switch are the biggest culprits.

For some background I was out with a car in a dirt lot getting an idea on how the brakes were reacting in extreme situations. The brakes have been a concern but I'll save that for another thread when I throw more at it.

I plan to plug the scanner in to it and see what is going on with it sometime in the future, mainly because it'* hot during the day and I don't feel like messing with it. My gut suggests the excursion in the dirt lot poking at the brakes may have upset something, but I also wasn't looking for this issue while driving either yesterday, and the car sat for over a week even before that. Cruise control is still working fine, although it seemed unwilling to pick up speed with it. The cruise control controls in this car have always been finicky in this car, but the issue persists even when CC is not engaged.

More to follow when I start poking at it. I feel like this is going to be one of those times I am glad I have the scanner and FSMs.
rjolly87 is online now   Reply With Quote
Old 09-02-2015, 08:33 PM   #2
Senior Member
True Car Nut
Thread Starter
 
rjolly87's Avatar
 
Join Date: Jun 2003
Location: Las Cruces, NM
Posts: 6,857
Thanked 298 Times in 246 Posts
rjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant future
Default

Today I plugged in the scanner in the driveway. No stored codes, TPS values are steady and consistent. It does show that the "TCC Brake SW" is "ON', however I seem to remember that being the case before the issue arose.

Given that I believe this model can detect if the TCC and associated hardware are not behaving properly, I am assuming at this point that lockup is simply not being commanded, which helps put my mind at ease for the time being on the expensive and complicated fixes. It also reinforces my gut feeling, the brake switch.

Next up is the road test with the scanner to confirm suspicions, which will be left for another day.
rjolly87 is online now   Reply With Quote
Old 09-02-2015, 10:46 PM   #3
Senior Member

Certified GM nut
 
Tech II's Avatar
 
Join Date: Feb 2014
Location: Worcester, Ma.
Posts: 2,147
Thanked 782 Times in 611 Posts
Tech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond reputeTech II has a reputation beyond repute
Default

At cruising speed of 65mph, and level ground, rpms should be under 2000 RPM'* if the TCC is engaging...
Tech II is offline   Reply With Quote
Old 09-02-2015, 11:13 PM   #4
Senior Member
True Car Nut
Thread Starter
 
rjolly87's Avatar
 
Join Date: Jun 2003
Location: Las Cruces, NM
Posts: 6,857
Thanked 298 Times in 246 Posts
rjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant future
Default

I usually cruise at 70mph, which calculates at 1916RPM, and sounds consistent with what I have seen in the past. The car now cruises at 2000-2400 depending on load, and never settles down like it does when the TCC locks. Also, touching the brakes at speed while on the throttle lightly now yields no change in vehicle behavior at all, where as in the past, the TCC would unlock, and RPMs would rise in to the range I am seeing now. I also see higher 3rd gear engine speeds than typical at cruise as well, despite the gear selector position.

It'* not working, I am 100% sure of that.
rjolly87 is online now   Reply With Quote
Old 09-03-2015, 09:08 AM   #5
Senior Member

True Car Nut
 
2kg4u's Avatar
 
Join Date: Sep 2006
Location: Windsor, Ontario / Detroit, Michigan
Posts: 4,804
Thanked 220 Times in 181 Posts
2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of
Default

Quote:
Originally Posted by rjolly87 View Post
I usually cruise at 70mph, which calculates at 1916RPM, and sounds consistent with what I have seen in the past. The car now cruises at 2000-2400 depending on load, and never settles down like it does when the TCC locks. Also, touching the brakes at speed while on the throttle lightly now yields no change in vehicle behavior at all, where as in the past, the TCC would unlock, and RPMs would rise in to the range I am seeing now. I also see higher 3rd gear engine speeds than typical at cruise as well, despite the gear selector position.

It'* not working, I am 100% sure of that.

If you have checked the obvious stuff (brake switch) take it to a transmission shop and have them read codes. Your scanner won't read the necessary codes.
2kg4u is offline   Reply With Quote
Old 09-03-2015, 12:22 PM   #6
Senior Member
True Car Nut
Thread Starter
 
rjolly87's Avatar
 
Join Date: Jun 2003
Location: Las Cruces, NM
Posts: 6,857
Thanked 298 Times in 246 Posts
rjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant future
Default

Quote:
Originally Posted by 2kg4u View Post
If you have checked the obvious stuff (brake switch) take it to a transmission shop and have them read codes. Your scanner won't read the necessary codes.
Which codes won't show up? I was under the impression that tranny codes show up under powertrain codes, and any code reader will pull any powertrain codes (OBD 1.5 aside)
rjolly87 is online now   Reply With Quote
Old 09-03-2015, 03:58 PM   #7
Senior Member

True Car Nut
 
2kg4u's Avatar
 
Join Date: Sep 2006
Location: Windsor, Ontario / Detroit, Michigan
Posts: 4,804
Thanked 220 Times in 181 Posts
2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of
Default

Quote:
Originally Posted by rjolly87 View Post
Which codes won't show up? I was under the impression that tranny codes show up under powertrain codes, and any code reader will pull any powertrain codes (OBD 1.5 aside)

Your impression is incorrect. Even my code reader that will pull ABS codes will not read transmission codes.
2kg4u is offline   Reply With Quote
Old 09-03-2015, 08:33 PM   #8
Senior Member
Posts like a Turbo
 
Join Date: Apr 2014
Posts: 419
Thanks: 0
Thanked 35 Times in 30 Posts
REGAL GUY has a spectacular aura aboutREGAL GUY has a spectacular aura about
Default

We have some very cheep scanners for general use from Auto Zone and they have no problem at all pulling up transmission codes.

Time to up date your scanner
REGAL GUY is offline   Reply With Quote
Old 09-04-2015, 04:54 AM   #9
Senior Member
Posts like a Turbo
 
Join Date: Apr 2014
Posts: 419
Thanks: 0
Thanked 35 Times in 30 Posts
REGAL GUY has a spectacular aura aboutREGAL GUY has a spectacular aura about
Default

rjrolly87 go take it for a drive and put your foot under the brake petal and pull it up see if its acts normal then.
Brake light switch could be just sticking enough to cause the problem
REGAL GUY is offline   Reply With Quote
Old 03-23-2016, 12:57 PM   #10
Senior Member
True Car Nut
Thread Starter
 
rjolly87's Avatar
 
Join Date: Jun 2003
Location: Las Cruces, NM
Posts: 6,857
Thanked 298 Times in 246 Posts
rjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant future
Default

Admittedly, the Regal hasn't seen much road action lately, but I decided to check in to this a bit further today because I was out for a nice empty stretch of interstate driving, and I happen to have the scanner with me.

Immediately, I was greeted with a code:
P0703 Brake Switch Failure
P0703 ? Torque converter/brake switch B -circuit malfunction ? OBD Trouble Codes

Kind of surprising, but not really. I would have thought it would knock out the cruise control at least, but I guess not. Brake lights and everything else seems to still work. The only symptom is no TCC lockup.

I had ordered a brake switch when I first started having the issue (they are cheap), so I guess I may as well get to putting that in soon. It'* obvious there is two parts to the switch in looking at it, and likely the bit that goes to the PCM has failed.
rjolly87 is online now   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
TCC (torque coinverter clutch)code and Evap code at same time?? (fixed) lobi Oldsmobile 16 02-24-2011 11:46 AM
Torque Converter Lockup Delay? rench Performance, Brainstorming & Tuning 13 09-27-2007 09:51 AM
Torque converter lockup question inthedirt Buick 7 03-29-2006 02:57 AM
Torque Converter Clutch thsncc1701 Buick 6 09-06-2004 11:34 AM
Is this typical torque converter lockup/unlock? DMC 1992-1999 10 01-12-2004 12:42 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 01:19 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.