TORQUE CONVERTER SERVO

[voicepro]

...I continue to enjoy my 98 DeVille...and the only Trouble Code I have tells me that there's an issue with the torque converter servo.

So how difficult is it to replace that servo? Is it buried somewhere inaccessible? Do you have to drop the transmission and/or

torque converter to replace the servo? Thanks for the input. (Note to Texas Jim: I keep forgetting to grab that camera from

my pal and send pics of my Cadillac, but I'll get to it eventually.)

[KHE]

Are you receiving the PCM P0741 code? If so, that is due to the seals in the torque converter apply circuit not sealing and the torque converter is slipping excessively. Big job - the transmission needs to come out, the internal seals need to be replaced, the torque converter needs to be replaced, and it is a good idea to replace the TCC solenoid while you're in there.

[Cadillac Jim]

If you are getting P0741 *and* P0743 or other code that indicates an electrical problem with the TCC solenoid, the problem *may* be limited to the TCC solenoid, which is one of the shifting solenoids. These can be changed with the transmission in the car.

[KHE]

If you are getting P0741 *and* P0743 or other code that indicates an electrical problem with the TCC solenoid, the problem *may* be limited to the TCC solenoid, which is one of the shifting solenoids. These can be changed with the transmission in the car.

I think if the PCM P 0741 code is set along with the PCM P1860 the issue is the TCC solenoid. It can be changed with the trans in the car but the powertrain must be lowered 10-12" in order to remove the side cover. It is still a PITA job.

If the PCM P0741 code is set by itself, it requires the trans. to be removed from the car.

[Cadillac Jim]

Yeah, either way that puts it out of my personal DIY range. If you're comfortable with raising the car a couple of feet, dropping the cradle, and working on it from a creeper, or if you have access to a lift and a place to work indoors, that's another matter.

I've had good luck with mechanics that have ASE certification. Look for this logo on a certificate in the office:

Find the name and date, and make sure that the certificate is less than five years old and that the person named works there, and will either do the work on your car or supervise it and sign it off.

[voicepro]

Many thanks for the information, gentlemen. I don't think there's any excessive slippage -- none I can sense, anyway -- but that code

tells me there's an issue (or about to be). Would this be the reason my Cruise Control is inoperative?

As an aside, one of my delights in this car is driving with the front windows open and hearing that smooth, powerful Northstar

wind up to about forty MPH. (Beyond that, the wind noise hides the engine sound.) I'm not doing jackrabbit starts or horsing

this car around -- just not called for -- but I've been in traffic situations where I've had to punch it a time or two, and it has

never failed to respond well.

I discovered (thanks to that on-board diagnostic setup) ignition issues, and replaced all four coils. This thing runs like

a scalded cat now. I'm well-pleased with it. Noted that in the past two weeks with a short commute to a job, I'm getting

twenty-plus MPG with combined freeway and in-town driving. As I said, I'm pleased.

[KHE]

Many thanks for the information, gentlemen. I don't think there's any excessive slippage -- none I can sense, anyway -- but that code

tells me there's an issue (or about to be). Would this be the reason my Cruise Control is inoperative?

As an aside, one of my delights in this car is driving with the front windows open and hearing that smooth, powerful Northstar

wind up to about forty MPH. (Beyond that, the wind noise hides the engine sound.) I'm not doing jackrabbit starts or horsing

this car around -- just not called for -- but I've been in traffic situations where I've had to punch it a time or two, and it has

never failed to respond well.

I discovered (thanks to that on-board diagnostic setup) ignition issues, and replaced all four coils. This thing runs like

a scalded cat now. I'm well-pleased with it. Noted that in the past two weeks with a short commute to a job, I'm getting

twenty-plus MPG with combined freeway and in-town driving. As I said, I'm pleased.

The slippage is integral to the torque converter - you will not feel it. It is not the transmission slipping as if the bands/clutches are shot. The torque converter uses a viscous fluid that allows it to "lock up" for better fuel economy. It is designed to slip so that the driver does not feel the torque converter locking and unlocking. If the slippage exceeds 200 RPM, the code sets and the service engine light illuminates. You'll notice a 2-3 MPG loss when the torque converter is not locking up.

Are there any codes set? That may point to the cruise control problem. There may be a misadjusted switch near the brake pedal or the cruise servo may be bad. There's pretty detailed flowchart in the shop manual on the cruise diagnostics. Maybe someone can post it here?

[Cadillac Jim]

I'll post cruise control information from the 1997 FSM but I would like to see the codes first, because that will probably cut down what I need to type in by 75% or so.