TCC Solenoid
 

My car cant decide whether or not to be in lockout right around highway speeds or cruising speeds (above 45) the tranny will bounce back and forth in and out of lockout code reads P1860 TCC Solenoid. My question is does this sound like if I replace the TCC solenoid will that fix it. Car shifts fine runs smooth no harsh shifts ever fluid level is good and pink no metal or chunks in it but it is really anoying when it bounces and trys to engage the clutch. It also kills the MPG because the RPMs are higher than they would be normally. i have seen the video and how to replace it just wish there was a better way to get to it then damn near pulling the engine. Any advice on this will be helpfull

What car are we discussing here? From the sound of it, it appears to be something with a Northstar/4T80E trans. If so, changing the TCC solenoid will most likely NOT solve the problem, tho the solenoid may indeed be melted, or otherwise defective. The main problem with this code is the seals in the channel plate that seal the converter lock-up feed oil...the seals wear, and the lock-up oil pressure drops to almost nothing, which causes the LU to engage/slip/disengage, and then set the code. When the seals leak, the TCC solenoid is commanded by the PCM to try to stop/control the slip, which causes the solenoid to overheat, and usually melt.
The only way to correct this issue is to remove the trans, and replace the two seals and TCC solenoid. The torque converter should also be replaced, since it has been subjected to repeated slippage.
It's not an easy job, by any means....

Hey thanks for the heads up on that now the only question is is it cheaper to light the car on fire and go buy a different one or to have a shop charge me out the A$$ to fix this one. Why is it that cadillacs do this and yet my Yukon XL Denali and my Suburban both the same year as my DTS (2002) that have over double the mileage (200K each) have never given me any problems at all?

Not the same transmissions...or designs. In this particular case, it is the design of the seals themselves. They were redesigned once to make them a little more durable, but the actual compound of the seal is just too hard. So far, the aftermarket has not made anything better, since the 4T80E is only used in a limited number of vehicles(Cadillac only now).
We usually get around $3000 for an overhaul on these things....very labor intensive to remove/replace.

That sounds about right I called a very reputable shop around the Spokane area and I was quoted 1750 to do the seals, TCC seloniod, and Torque Converter if needed. Do you think it is worth it to just put a new trans in with a warranty? They also said it might not be a bad Idea to do head gaskets while they have it apart. What do you think? And thank you very much for taking the time to answer mine as well as many others questions.

Whether or not it's worth it depends on how much you like the car, really. I recently had to do the 4T80 in one of my own cars. I just swapped it out for one I already had built to save down time. If the car was a big turd, and I was having a lot of other problems with it(other than the trans), I might not have done it. I've sent several of my Cads to the junk yard(or a "Cars for Kids" program) because they weren't worth me putting any more $$$$ or time into them.
Honestly, I wouldn't go thru the trouble of removing/replacing the trans, and tearing into it to replace the TCC seals without overhauling it. That's just me...I'm in the trans business, so I can do my own stuff fairly cheap.
Overall, the trans is a pretty good design...really heavy duty, but there are some wear issues with the clutches, and the overdrive band. If the OD band burns, it can take the reverse input drum with it...not exactly a cheap deal.
Couldn't say about the head gaskets....I see a LOT of issues with them on this site, so there's obviously a problem with them, but you'll see that with any all aluminuminum engine, imo. Again, it just depends on how well you like the car, and how long you want to keep it.
hth :D

Anyone familiar with the electrical in 1999 sls caddy. I put a brand new bat. in car year 1/2 ago runs fine. Winter comes, gets too cold over night battery is drained must jump in morning, and it starts right up. Has 57,000 original miles 1999 sls. Take real good care. Does anyone have a troubleshooting thought on where I should start w/o it costing me a face job? Any suggestions would highly valuble.
Respectfully,
D.A. Clark

@Adams Apple
Thank you for assisting with the trans trouble I wrote about a couple weeks ago.
1998 Seville STS
To summarize, P0741 code (and a few other trans related codes) appeared (about after the time I changed out the high pressure PS hose) and the trans was in single shift - emergency mode.
Took it to a dealer (Stevinson Chev - Lakewood, CO) for confirmation of the bad news - an overhaul was assumed.
The fluid was clear and no shavings were found.
I had not taken up the slack in the PS hose sensor wiring, and it's rubbing on the drive shaft caused a bare wire.
The transmission and the PS hose electrical are on the same circuit. A blown fuse caused the transmission to go into it's fail safe mode.
A hundred dollars for: the inspection, dropping the pan and changing fluid and filter, and a 10 A fuse

How is the vehicle running today? I hope that trip get things resolved.

Michelle, Cadillac Customer Service

I have a question about that also, I have a 1994 SLS that gets code P039 past about 45 and it turns off under.

I know I need to flush the trans and install a new filter but did the 94 have a TCC? If so is it under the trans oil pan like other models or inside the trans?

Does the TC on a 94 have a plug to drain it or will I need to have it flushed by someone?