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01 SLS TCC Replacement

03-01-2009, 10:35 PM
anyone got any shortcuts to changing the TCC Solenoid on an 01 Cadillac SLS?

Also When the car is running I hear a loud Hissing (sounds like a vacuum leak) inside the car (not the engine compartment) any ideas on what that could be?

Thanks In advance

03-02-2009, 02:29 PM
Pan comes off the trans to access the TCC solenoid, no tricks here. Without hearing this " hissing" no chance to help on this from here.

03-02-2009, 09:43 PM
No short cuts for that repair...sorry!!! The solenoid is located behind the side cover on a 4T80E transaxle and to replace it will require lowering the LH side of the front frame, lowering the transmission quite a bit in order to remove the side cover. While this job can be done on the floor using a floor jack and jack stands, its best to do it on a vehicle lift.

btw...what is the concern/problem for the TCC solenoid replacement? If U have a dtc #P0741, its best U look deeper into the trans. The correct repair will require trans removal and disassembly. Usually the cause is worn seals on the drive sprocket bearing inner race on the drive sprocket. There have been cases that the cause was debris in the valve body, but the number of failures due to this concern was very low.

The hiss noise is most likely a loose or disconnected vac line behind the dash for the HVAC system. Listen closely by the glove box...if the noise is loudest there, remove the glove box and have a look. Many of the leaks are in that area

03-02-2009, 10:46 PM
thanks, but I do have code P0741 along with P1860 and everything that I searched says to fix Codes 1860 (TCC Stuck off) - bad TCC SOLENOID.

03-03-2009, 05:49 AM
I hope U realize P1860 is a manufacturers specific code...the >1< signifies that. This code means there is a loss of ignition voltage to the shift solenoids. Does the trans have all 4 gears and does it start off from a stop in 1st gear? if so, then ignore that code for now. This code could be caused by a remote start system incorrectly installed among other things.

If the only other code is the 741 and U want to verify its operation before doing a tear down, find a scanner or someone who has one and command the TCC solenoid on & off and listen for the click sound under the hood next to the trans...use a long screw driver held against your ear to listen and touch the trans side cover. Ive see and repaired more Caddy's for the 741 code than I can remember, so with absolute confidence...I'm just about 100% certain your problem will require tear down to repair it correctly.

Yes there is a remote chance U only have a bad solenoid or even loss of ignition voltage, but until U verify and confirm what I just asked, I'll stick to what I said...good luck and post back your results.

03-03-2009, 06:03 AM
I am a MECHANIC, I have a SNAP-ON SOLUS PRO Scanner at work which is what I used to get the codes. It starts out in first and shifts fines until 4th gear, it will not shift into fourth gear. I did some searching and this is where I found out that the TCC Solenoid is bad and needs to be replaced and it said replacing the bad TCC Solenoid should take care of any other codes (especially when there is a P0741 and a P1860) There were 2 other codes, don't remember right off hand what they were, I also talked to my local GM Dealer and they said they sell alot of these TCC solenoid for these transmissions.

03-03-2009, 06:12 AM
Thats as U see fit, just be sure to check what I mentioned before U just replace the TCC solenoid.

FWIW...I've been a GM tech for over 30 yrs and have fixed hundreds if not more of the 4T80E transaxles for a 741 some have even required a new torque conv

good luck...

03-03-2009, 06:19 AM
I'm not trying to argue with U, just trying to help...check your PM's I sent U a copy paste of a TSB that covers your condition

03-03-2009, 04:40 PM
The tcc solenoid has no affect on 4th gear here, only tcc engagement, I'd research this a little further.

03-04-2009, 06:11 AM
I got the PM's, I will check it out when I get the tranny out

03-04-2009, 06:40 AM
The tcc solenoid has no affect on 4th gear here, only tcc engagement, I'd research this a little further.

And yes, when the TCC Solenoid goes bad you lose O/D (4th gear)/have and irractic TCC Lockup and O/D disengage.

03-12-2009, 06:42 PM (

here is the pic of the TCC Solenoid out of the caddy. It was deffinately bad, I didn't have to remove the entire tranny to get it out so I didn't bother checking for any thing else as soon as I went to unplug the TCC Solenoid it just fell apart. I got it back together 2day, cleared the codes, and put about 23 miles on it and it shift like a dream, I hope i don't have any other problems with anything else. thanks for you help guys.

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