[katieperez]

Hello all! I've got a 98 Deville that I love to pieces. Anyway, a while back, the service engine soon light came on and I took it to Aamco. Since I have a Northstar engine, the guys said they'd have to drop my whole engine to get to my tranny to even find the problem. Well I'm not made of money (roundabouts 3000.00) and since she's driving just fine, I left it alone. I know that spells a recipe for trouble, but they said it could be a 4 months or 4 years before she started to give me any trouble. There's just no way of knowing when exactly. They suspected a cillanoid gone bad. It's been about a year with no problems. The light will come and go. A few weeks on, a few weeks off. All that said, my question is, if it is indeed a cillanoid as suspected, what kind of trouble will she be in? Anyone out there know Cadillacs pretty well? Will my engine lock up while Im driving or will my car just fail to start one morning?

[TxGreaseMonkey]

If there's a problem, these days, most dealers will drop in a rebuilt transaxle. What I would do is change the transmission fluid and filter, using Mobil 1 Synthetic Multi-Vehicle ATF. The higher detergency and resulting higher pressures may solve the solenoid problem.

Here's how to do the job yourself:

https://www.askmehelpdesk.com/cars-t...tml#post552241

If the transaxle is sludged-up, look into Auto-RX.

[katieperez]

Hey thanks a bunch! I'm about due for an oil change and I actually printed your answer so I won't forget the name of the stuff! I also printed the instructions in case my husband feels up to the job! Thanks again, hopefully that will fix it.

p.s. I figured I had solenoid spelled wrong:)

[TxGreaseMonkey]

The Mobil 1 Synthetic Multi-Vehicle ATF is available at WalMart.

[TxGreaseMonkey]

Ensure the pan is dropped, cleaned, and a new filter is installed. Don't use a T-Tech machine, where the pan is not dropped, cleaned and new filter is not installed. The later approach can lead to transaxle failure in short order.

[Lowtax4eva]

Also to add, if it's a bad solenoid the car will just simply not start one day, no danger of it shutting off while driving.

[macksmom]

This is Macksmom's husband... I am a technician for a Cadillac dealership...

They are probably talking about a shift solenoid, which is more than likely located in the lower valve body (this transmission has 2 valve bodies).

It wouldn't cause any starting issues, the only thing it would do is cause a shift issue.

While flushing the fluid is a good idea, it may not solve the problem.

More than likely if everything is working okay it is an electrical issue. I know many people hate taking their cars to the dealer, but we have the best and most info available to correctly diagnose the problem.

Many problems are fixed by a simple reprogram than a $3,000 rebuild, also these vehicles have many problems with the PCM which is covered under a 10 year/100K mile warranty, that many owners don't know about.

Hope this helps a bit!

[CaptainRich]

Hello all! I've got a 98 Deville that I love to pieces. Anyway, a while back, the service engine soon light came on and I took it to Aamco. Since I have a Northstar engine, the guys said they'd have to drop my whole engine to get to my tranny to even find the problem. Well I'm not made of money (roundabouts 3000.00) and since she's driving just fine, I left it alone. I know that spells a recipe for trouble, but they said it could be a 4 months or 4 years before she started to give me any trouble. There's just no way of knowing when exactly. They suspected a cillanoid gone bad. It's been about a year with no problems. The light will come and go. A few weeks on, a few weeks off. All that said, my question is, if it is indeed a cillanoid as suspected, what kind of trouble will she be in? Anyone out there know Cadillacs pretty well? Will my engine lock up while Im driving or will my car just fail to start one morning?

There is definitely a way to determine the fault. The tech can use the GM TECH II scan tool. Experienced GM/Cadillac techs should have recommended this first.

You didn't tell us what the code was. A VERY common fault code for this vehicle is P0741. This code relates to a problem with the torque converter apply circuit. Replacing fluid will not affect the apply fluid circuit at all. There are several internal components that will be required to thoroughly repair this concern. The solenoid is only part of that repair. Rarely, and I mean very rarely, the problem that causes this code can actually be the PCM.

On the other hand, I've seen many of these vehicles driven for thousands of miles and never had anything lock up. Gas mileage may suffer slightly due to the converter not engaging, thus not providing the optimum final drive ratio. One problem with leaving the check engine light on is that if another problem were to occur, you won't no about it because the light is already on.

If you PM me, I'll walk you through the steps to clear the codes and reset the MIL.
Please read my profile.

[finchley]

There is definitely a way to determine the fault. The tech can use the GM TECH II scan tool. Experienced GM/Cadillac techs should have recommended this first.

You didn't tell us what the code was. A VERY common fault code for this vehicle is P0741. This code relates to a problem with the torque converter apply circuit. Replacing fluid will not affect the apply fluid circuit at all. There are several internal components that will be required to thoroughly repair this concern. The solenoid is only part of that repair. Rarely, and I mean very rarely, the problem that causes this code can actually be the PCM.

On the other hand, I've seen many of these vehicles driven for thousands of miles and never had anything lock up. Gas mileage may suffer slightly due to the converter not engaging, thus not providing the optimum final drive ratio. One problem with leaving the check engine light on is that if another problem were to occur, you won't no about it because the light is already on.

If you PM me, I'll walk you through the steps to clear the codes and reset the MIL.
Please read my profile.

I have a similar problem. I'd like to also walk through the steps to clear and reset the MIL. Where do I email? Ed

[alittlehelpneed]

With the onboard computer why would you use the tech2 or similar?
It can be accesed with the buttons on the dash.