Jump to content
CaddyInfo Cadillac Forum

No TCC Lockup '03 DTS


John Wicz

Recommended Posts

Hi,

I recently (this morning) noticed that the Torque Converter Clutch on my '03 DTS (with 37K miles) is not locking up. I have no codes (yet), the fluid is at 99%, never changed, full and looks clean. I've checked the cruise control brake pedal switch and readjusted it to no avail.

Anyone have any consoling thoughts or ideas???

Thanks,

--John

Link to comment
Share on other sites


What are the exact symptoms while driving? It is odd that it is not showing any codes.

After the car shifts into high gear, the lockup doesn't occur and the RPM's stay high and don't drop like they should after lockup.

Link to comment
Share on other sites

What are the exact symptoms while driving? It is odd that it is not showing any codes.

After the car shifts into high gear, the lockup doesn't occur and the RPM's stay high and don't drop like they should after lockup.

Sounds not good. Another way to check the function is keeping constant speed say, at 50 MPH and touching with left foot the brake pedal just to activate the brake switch. If lock up works you should see RPMs jumping up some 100-200 RPM since brake switch will disengage the TCC.

The saddest thing in life is wasted talent

Link to comment
Share on other sites

What are the exact symptoms while driving? It is odd that it is not showing any codes.

After the car shifts into high gear, the lockup doesn't occur and the RPM's stay high and don't drop like they should after lockup.

Sounds not good. Another way to check the function is keeping constant speed say, at 50 MPH and touching with left foot the brake pedal just to activate the brake switch. If lock up works you should see RPMs jumping up some 100-200 RPM since brake switch will disengage the TCC.

Been there, done that, RPMs don't increase.

Link to comment
Share on other sites

Update: This morning the TCC locked up evertime. Not sure what to make of this, maybe heat brings the problem out, maybe a fluke, now I'm really confused........................

Link to comment
Share on other sites

I would suspect the brake pedal switches. Or at least eliminate them as a possible cause.

Do your stop lights work properly? Is the cruise control operating properly? All of these systems (and more) use signals from the two switches actuated by the brake pedal.

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

Link to comment
Share on other sites

I would suspect the brake pedal switches. Or at least eliminate them as a possible cause.

Do your stop lights work properly? Is the cruise control operating properly? All of these systems (and more) use signals from the two switches actuated by the brake pedal.

I removed both switches, checked them out and re-installed them per the FSM. Yes, cruise and brake lights work properly.

Link to comment
Share on other sites

Update: This morning the TCC locked up evertime. Not sure what to make of this, maybe heat brings the problem out, maybe a fluke, now I'm really confused........................

As Jim noted it has to be something like the brake switch as it's not setting a code. It's TERRIFIC news that it's not setting a code. You need to find out what functions cause it not to engage or to disengage without setting a code.

Something tells me that if your brake switch was creating a problem that the PCM would eventually flag that.. but I don't know that for sure.

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

Update: This morning the TCC locked up evertime. Not sure what to make of this, maybe heat brings the problem out, maybe a fluke, now I'm really confused........................

As Jim noted it has to be something like the brake switch as it's not setting a code. It's TERRIFIC news that it's not setting a code. You need to find out what functions cause it not to engage or to disengage without setting a code.

Something tells me that if your brake switch was creating a problem that the PCM would eventually flag that.. but I don't know that for sure.

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

Update: This morning the TCC locked up evertime. Not sure what to make of this, maybe heat brings the problem out, maybe a fluke, now I'm really confused........................

As Jim noted it has to be something like the brake switch as it's not setting a code. It's TERRIFIC news that it's not setting a code. You need to find out what functions cause it not to engage or to disengage without setting a code.

Something tells me that if your brake switch was creating a problem that the PCM would eventually flag that.. but I don't know that for sure.

I wish that I was as optimistic as you are. But, the fact that the brake switch also controls turning off the cruise control when depressed, and that worked fine??? I don't know what to think and guess I'll have to see if a code eventually gets set.

Link to comment
Share on other sites

Just to clarify that you HAVE gone into the diagnostics to check for codes, and have not simply relied on the MIL to turn on? This may not be a problem that would illuminate the MIL, I'm not sure.

I agree that if it's not setting a code, there's likely not a hard fault anywhere. It may have been that the circumstances just didn't allow the TCC to engage.

Interesting side story, and possibly related, my '97 SLS exhibited symptoms that may have been from the same problem, although I never traced the cause. When not using the cruise control, the TCC would engage everytime, when it was allowed to (in general, anytime the transmission upshifted into 4th gear). However, whenever I would engage the cruise control, and the problem got more chronic over time (months), the TCC would unlock. It would stay unlocked for a random amount of time. Usually 10+ seconds, but sometimes as long as a minute or more. Then it would re-engage. The brake pedal would ALWAYS unlock the TCC (as it should), and both the brake lights and cruise control otherwise worked fine. But for some reason, the TCC would unlock momentarily when engaging the cruise control, something that the car didn't originally do, and a problem which would increase with frequency over time. It seems to indicate some mis-adjustment somewhere, but with all functions otherwise normal, and with the TCC eventually re-engaging, I never looked into it. My brother now owns the car and hasn't complained about the problem, but I'm sure he just doesn't notice it. It wasn't bothersome, and was only apparent by staring at the tach (I admit, I'm a gauge-watcher).

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

Link to comment
Share on other sites

Just to clarify that you HAVE gone into the diagnostics to check for codes, and have not simply relied on the MIL to turn on? This may not be a problem that would illuminate the MIL, I'm not sure.

I agree that if it's not setting a code, there's likely not a hard fault anywhere. It may have been that the circumstances just didn't allow the TCC to engage.

Interesting side story, and possibly related, my '97 SLS exhibited symptoms that may have been from the same problem, although I never traced the cause. When not using the cruise control, the TCC would engage everytime, when it was allowed to (in general, anytime the transmission upshifted into 4th gear). However, whenever I would engage the cruise control, and the problem got more chronic over time (months), the TCC would unlock. It would stay unlocked for a random amount of time. Usually 10+ seconds, but sometimes as long as a minute or more. Then it would re-engage. The brake pedal would ALWAYS unlock the TCC (as it should), and both the brake lights and cruise control otherwise worked fine. But for some reason, the TCC would unlock momentarily when engaging the cruise control, something that the car didn't originally do, and a problem which would increase with frequency over time. It seems to indicate some mis-adjustment somewhere, but with all functions otherwise normal, and with the TCC eventually re-engaging, I never looked into it. My brother now owns the car and hasn't complained about the problem, but I'm sure he just doesn't notice it. It wasn't bothersome, and was only apparent by staring at the tach (I admit, I'm a gauge-watcher).

Yes Jason, I HAVE gone into diagnostics and even hooked up a code reader just to make sure, no codes. I admit also to being a gauge watcher (or else I might not even know that the TCC was not engaging).

Link to comment
Share on other sites

Try resetting the transmission connector, use some electrical contact cleaner. Hope this chart helps:

NoTCCEngage.jpg

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

Try resetting the transmission connector, use some electrical contact cleaner. Hope this chart helps:

NoTCCEngage.jpg

Thanks, I'll clean the connector. The TCC did lock up fine during my driving today (about 45 miles).

Link to comment
Share on other sites

I sort of have a weird situation related to that. I know for a fact that my torque converter locks and unlocks just fine, but I can never get it to unlock with the brake pedal. Maybe I'm not pushing it enough or maybe I don't do it long enough. I know the brake switch is working because of the cruise and brake light work. No codes either. I know it's locking and unlocking because when I go up a hill at highway speeds and it will sometimes unlock and jump up a couple hundred rpm. Maybe I'm just not paying attention...

Jason, mine also unlocks while I engage the cruise sometimes and it has done it ever since I bought it. Maybe it's supposed to do that, anyone else have that?

-Dusty-

- 02 Seville STS, white diamond

- 93 Sixty Special, Tan with vinyl top

- 79 Coupe DeVille, Tan with Tan top

- 06 GMC Sierra Z71, Black

- 92 Silverado C1500, black and grey

- 83 Chevy K10 Silverado, Black and Grey

b80385550.jpg

Link to comment
Share on other sites

Jason, mine also unlocks while I engage the cruise sometimes and it has done it ever since I bought it. Maybe it's supposed to do that, anyone else have that?

Your '02 does that? It shouldn't...my '97 was the only car I've had that did that, and it didn't originally do it...which tells me that it's not supposed to.

The only time it might "should" do it is if you're going significantly slower than the set speed, and press RESUME, and the TCC unlocks due to the momentary sudden increase in throttle. Otherwise, the TCC should stay engaged with cruise operation.

The fact that your TCC doesn't unlock with the brake pedal really leads me to believe that your problem (and probably my ex-problem, on the '97) is a switch.

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

Link to comment
Share on other sites

My TCC stays locked when I engage the cruise control. 1997 ETC with about 130,000 miles. I service my transmission every 30,000 miles.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

Link to comment
Share on other sites

I sort of have a weird situation related to that. I know for a fact that my torque converter locks and unlocks just fine, but I can never get it to unlock with the brake pedal.

If it was not unlocking with the brake pedal, the engine would stall when you stopped, much like stopping a standard trans without stepping on the clutch.

Link to comment
Share on other sites

I sort of have a weird situation related to that. I know for a fact that my torque converter locks and unlocks just fine, but I can never get it to unlock with the brake pedal.

If it was not unlocking with the brake pedal, the engine would stall when you stopped, much like stopping a standard trans without stepping on the clutch.

Good point. I must not be paying enough attention.

Jason, I'm going to check that again to see if it actually does it. Maybe it is on resume that I'm thinking of. I'll let you know later today.

-Dusty-

- 02 Seville STS, white diamond

- 93 Sixty Special, Tan with vinyl top

- 79 Coupe DeVille, Tan with Tan top

- 06 GMC Sierra Z71, Black

- 92 Silverado C1500, black and grey

- 83 Chevy K10 Silverado, Black and Grey

b80385550.jpg

Link to comment
Share on other sites

OK, I was wrong. The brake does unlock the torque converter. I haven't checked the cruise thing though. I'll find that out later.

-Dusty-

- 02 Seville STS, white diamond

- 93 Sixty Special, Tan with vinyl top

- 79 Coupe DeVille, Tan with Tan top

- 06 GMC Sierra Z71, Black

- 92 Silverado C1500, black and grey

- 83 Chevy K10 Silverado, Black and Grey

b80385550.jpg

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...