Can you help me ?

Where is the transmission Control Solenoid located on a 1997 STS ?

... (this one) Your Parts Search Returned 1 Part(s)

What, if anything, needs to be removed first, in order to access the solenoid ?

Thanks in advance.

 

The PCS(Pressure control solenoid), and the TCC(torque converter control) solenoids are under the side cover of the trans. The two shift solenoids are in the bottom pan of the trans. The shift solenoids can be replaced by removing the bottom pan, and the lower valve body. The PCS, and TCC solenoids require much more to get to...usually easiest to remove the transmission from the vehicle, tho I have heard of some being able to loosen the side cover enough to get to/replace the solenoids. IMHO, by the time you get that far, a few more bolts will have the trans out anyway...
The link you have shows a shift solenoid, which can be done with the trans in the car, but it does require removing, and dis-assembling the lower valve body. The two shift solenoids for the 4T80E are different, and it's best to replace both at the same time. On your '97, there should already be an updated bracket installed to hold a filter in place. On the earlier cars, this filter would pop out of the valve body, and break a solenoid in the process. The bracket was put into service to keep the filter from popping out.

Why do you need to replace?

 

Thank you for that thorough and clear description.

I got that solenoid on a hunch. It's possible I may have gotten a little ahead of myself,
but, nevertheless, here are the problems:

1. With the engine running and car standing still,
shifting from N into D,
it takes the transmission a couple of seconds to engage.

2. Then, while driving,
the two lower gears seem to drive/shift more-or-less normally,
but, the upper gears will not engage unless I take my foot completely off of the accelerator pedal.
After that, even a little pressure on the accelerator causes the transmission to downshift.

What I've found so far:
Reverse engages promptly and normally.
Whoever serviced the transmission the last time over-filled it...by about a quart and a half.
I've already removed the excess fluid, so the fill level is now correct.
Fluid looks basically red, and there's no obvious burnt smell.

Based on your explanation, replacing the two shift solenoids sounds doable.
The PCS and TCC...uh...not so much.

You say the two shift solenoids are different.
Can you tell which one it is that I already have ?

Also, if the updated filter bracket is not already there, is installing one a simple bolt in process ?

Thanks.

 

You can purchase a complete shift solenoid kit off e-bay that contains both solenoids, the bracket, a new filter(the one that blows out), and a longer bolt to hold the bracket on. Solenoid Kit The OE part numbers for the 2 shift solenoids are the same: #24207662..I was incorrect in stating they are different, but they do index in the valve body differently. Sorry for that...I musta been thinking about something else. The OE part number for the update kit (as linked to above) is #24211355. You might be able to find one of these kits at a dealer, but the ebay price is pretty reasonable. And yes, the bracket is a simple bolt-on deal, but it does require the longer bolt, included in the kit(s). You WILL need to disassemble the lower valve body to change the solenoids...they installed the clips from the inside at the factory. I always put the clips in from the other side when I do them, so they are easier to get to next time, if needed. I would recommend the purchase of a Factory Service Manual(for the drivetrain) for detailed info on how to do this without creating more problems in the process. hth

 

Thanks for the info on the solenoid kit. That seems the way to go.

Based on the transmission's symptoms,
What do you think the odds are that installing the solenoid kit will improve its operation ?

Also, the clips you mentioned,
What function do they serve ?

I'll try to locate a Factory Service Manual, but absent one, any tips on the trickiest parts of the procedure would be much appreciated.

Does the lower valve body unbolt from the rest of the transmission ?, or,
Is it disassembled in place ?

Thanks, again.

 

The clips I referenced are the ones that hold the solenoids to the valve body. I'll try to post a pic of the set-up this evening if I can get time.
The valve body is held to the trans by many 10mm headed bolts, and 2 10mm nuts. You will NOT need to remove ALL of the bolts...some do not go into the case. If you look closely, you will see which ones actually do, and the ones that do not.
You will need to disconnect the electrical harness at the front edge of the valve body, leaving all of the solenoids connected for now.
One really tricky thing is disconnecting the manual linkage...it is held to the shifter linkage by a small, black plastic clip. You can almost bet the farm that that clip will break, but...if it is not too brittle, and you are very careful, you will be able to get if off without it breaking. I keep a sack of them in my toolbox, because they do break so often. You should still be able to get one from the dealer, but I do not have a part number for it...I might be able to find the number...I'll post later.

 

Adams' Apple
When would you know when the tranny need's rebuilt/replaced?
1998 Seville STS - 188K mi
P0741 indicates TCC stuck open
Nearly the same driving conditions - except it's already just in emergency gear. Meaning, it drives but will not shift>

Thank you

 

P0741 is a common problem on these. It's usually caused by the seals in the channel plate that seal lock-up oil pressure going to the converter. Once the converter starts slipping, or failing to lock-up properly, the PCM attempts to stop the slippage by ramping up the amperage to the solenoid...which eventually melts the solenoid. This always requires trans removal to repair...just replacing the solenoid will not correct the real problem.
As far as when to know if it "needs" an overhaul, there's no one real indicator for that. If it's not shifting, or slipping, the first thing to do is check the fluid level, and condition. Burnt smelling fluid is a dead giveaway. Driving one in failsafe mode, or "emergency gear", is sure to accelerate any wear/tear already done. These transmissions are pretty dang stout, but driving one with a malfunction will cause damage to some pretty expensive parts inside, if not taken care of asap.
hth

 

Sensei Adam's Apple -
Thank you for the response!
Having had no car payment for several years now, and repairs less than $1k, it's now time to weigh spending $3k for a tranny overhaul or let her go.
I've put Arnott McPherson struts with dummy sensors on the front, brakes all around, water pump, and high pressure PS line.
The engine was replaced, gratis GM (tip o the hat) due to packing material in the water jacket at 55k miles.
A freak accident (painters sign bounced off truck and across hood and roof) repainted the hood and fenders.
It's a frekkin awesome ride and draws looks. Lipstick RED, Strong Northstar 32v, all the trimmings.
KBB says it's ONLY worth $5k.
Then, I've been "cheating" in my heart. I want the Benz 350SL 3rd Ed convertible (1972) available from buddies mother.
You've helped tremendously. I feel I should buy you a drink.