: My 1996 Sedan Deville won't go over 40 mph?



ronae
02-19-04, 10:40 PM
I am having a problem with my 96' Sedan Deville shifting gears. When the car gets up to 40 mph it seems to just drop out of gear, but if I press on the accelerator the rpms jump up but the car does not move any faster? As soon as I let the car fall back down below 40 mph, the gear comes back. I have taken my vehicle to a transmission specialist and was told to have the electrical system checked? As a matter of the fact, now it's not changing gears at all. It seems to be stuck in 2nd gear even with acceleration being applied? Can anyone help answer this question?

The_Raven
02-20-04, 12:22 AM
Howyadoin,

Are you getting any "Service Engine Soon" indicators on the dash? IMHO, it sounds a lot like what happened to me when my transaxle shift solenoids died on my '93 STS, but it's hard to say there's any connection, so don't take that as gospel. If you're getting a SES light, finding the current problem codes would be helpful.

Simultaneously press and hold the OFF and WARMER buttons with the key on to access the onboard diagnostics and read off the codes displayed. This should provide a clue as to what has happened.

Big Jim
02-20-04, 05:03 AM
Sounds kind of similar to the problem I had with my '94. In my case, it was bad news. Internal parts failure requiring a major overhaul with about $2K in parts. I hope yours is less serious.

ronae
02-20-04, 10:39 AM
Howyadoin,

Are you getting any "Service Engine Soon" indicators on the dash? IMHO, it sounds a lot like what happened to me when my transaxle shift solenoids died on my '93 STS, but it's hard to say there's any connection, so don't take that as gospel. If you're getting a SES light, finding the current problem codes would be helpful.

Simultaneously press and hold the OFF and WARMER buttons with the key on to access the onboard diagnostics and read off the codes displayed. This should provide a clue as to what has happened.
No warning lights, nothing? It just won't shift gears?

BeelzeBob
02-20-04, 12:20 PM
I am having a problem with my 96' Sedan Deville shifting gears. When the car gets up to 40 mph it seems to just drop out of gear, but if I press on the accelerator the rpms jump up but the car does not move any faster? As soon as I let the car fall back down below 40 mph, the gear comes back. I have taken my vehicle to a transmission specialist and was told to have the electrical system checked? As a matter of the fact, now it's not changing gears at all. It seems to be stuck in 2nd gear even with acceleration being applied? Can anyone help answer this question?


Understand that the 4T80E transmission defaults hydraulically to second gear if it looses electronic control either because of lack of power to the trans (electrical power that is) , a missing or loose wire connection, loss of the trans shift solenoids, etc....

I would start by checking the electrical connector to the trans which is in the bell housing area of the trans. There is a large round electrical connector that interfaces the trans with the engine compartment harness. Check fuses and such also.

What you describe for the operation of the trans sounds exactly like the second gear default mode. It still has drive and will move the car but in second gear. It has no engine braking...i.e...when you accelerate to higher speeds and lift off the throttle the engine drops down to idle and the car coasts along. If you press the throttle the engine RPM has to flare fairly high to "catch up with" the car speed and then it will drive it forward. That is the second gear default.

I, too, would suspect an electrical problem.

Did you check the onboard diagnostics by simultaneously pressing and holding the OFF and WARMER butttons with the key on until the onboard diagnostics activates???

On your car the PCM is in the air box for cooling purposes. Open up the induction system and check the connections to the PCM inside the air box to make sure that the large wiring connections to the PCM are intact.

ronae
02-20-04, 11:51 PM
GOOD information! You sound as though you know what the problem may be. You have explained it to a tee.

I took the car to a transmission dealer and he said because he thinks the problem may be electrical, he wanted me to take it to an electrical shop. However, I spoke to the electrical guy and he said that because the car is computerized, it may be an electrical problem, but it has something to do with the tranny and that is out of his league? Makes sense to me! So, to make a long story short, the transmission mech. is preparing to run a diagnostics test to determin the root cause. I think you are more familiar with the situation than the transmission mechanic! :)

As far as testing the onboard diagnostics, all checked out well.
I am new to this Web site, but I never realized there were so many mechanical problems with a Caddi?



Understand that the 4T80E transmission defaults hydraulically to second gear if it looses electronic control either because of lack of power to the trans (electrical power that is) , a missing or loose wire connection, loss of the trans shift solenoids, etc....

I would start by checking the electrical connector to the trans which is in the bell housing area of the trans. There is a large round electrical connector that interfaces the trans with the engine compartment harness. Check fuses and such also.

What you describe for the operation of the trans sounds exactly like the second gear default mode. It still has drive and will move the car but in second gear. It has no engine braking...i.e...when you accelerate to higher speeds and lift off the throttle the engine drops down to idle and the car coasts along. If you press the throttle the engine RPM has to flare fairly high to "catch up with" the car speed and then it will drive it forward. That is the second gear default.

I, too, would suspect an electrical problem.

Did you check the onboard diagnostics by simultaneously pressing and holding the OFF and WARMER butttons with the key on until the onboard diagnostics activates???

On your car the PCM is in the air box for cooling purposes. Open up the induction system and check the connections to the PCM inside the air box to make sure that the large wiring connections to the PCM are intact.

BeelzeBob
02-21-04, 10:04 PM
GOOD information! You sound as though you know what the problem may be. You have explained it to a tee.

I took the car to a transmission dealer and he said because he thinks the problem may be electrical, he wanted me to take it to an electrical shop. However, I spoke to the electrical guy and he said that because the car is computerized, it may be an electrical problem, but it has something to do with the tranny and that is out of his league? Makes sense to me! So, to make a long story short, the transmission mech. is preparing to run a diagnostics test to determin the root cause. I think you are more familiar with the situation than the transmission mechanic! :)

As far as testing the onboard diagnostics, all checked out well.
I am new to this Web site, but I never realized there were so many mechanical problems with a Caddi?
Possibly your best bet might be a Cadillac dealer.... They will have the service support that will understand the trans and the electronics and they should be able to trouble shoot the problem easily....

There aren't that many Cadillac problems...LOL. Any internet site always is full of problems whether it is a Cadillac, Toyota, Westinghouse, GE or whatever.... site. People, like yourself, rarely if ever search out an internet site to brag about how good their car is running but when they do have a problem they look up an internet site for info. So it is expected to see a lot of "problems" on any site. Look up other sites for other makes of cars and see.

Dubya
02-22-04, 01:04 PM
go to a cadillac dealership, i had the EXACT same problem with the exact same symptoms. were at speeds above 40 it feels like its in nuetral, but if you push it down it will eventually "catch", for 2 days i had to speed up to 55ish then coast down to 35ish and keep doing that!


i had a broken shift solenoind, should cost you about $400 at the most. VERY COMMON what happens is there's a filter tube between the solenoids, it slides in and out, the only thing from keeping it from comming all the way it is it actually hitting one of the solenoids. thats the solenoid that always breaks. the solenoid replacement kid comes with a bracket to hold the filter in place. i believe it was mid year 96 when they started putting the bracket in all 4t80e's.

ronae
02-24-04, 08:45 PM
Thanks for all the good information. Well, my transmission mechanical said that he could not locate the problem and the on board diagnostics test displayed no symptoms. I will be taking my baby to the dealership tomorrow. I will let you know the end results.

Thanks for everything! :)

By the way...you were right about other sites with major problems! Have a good one.

RP~

ronae
02-27-04, 10:02 AM
OK. I have taken my baby to the "REAL" doctor (dealership) and it has been diagnose with having two broken solenoids. You were correct! It will cost my $790.00 + tax to get fixed. This includes parts and labor.

Thanks for everything!

Dubya
02-27-04, 10:19 AM
i wouldn't ever go to that dealership again. where do you live? if your in MN, id recommend APPLE VALLEY walser cadillac. there is NO excuse for them to charge $800 for that, i paid $400. both solenoids come in a package together for like $70ish dollars. $50 for gasket/filter, maybe $20 in fluid, grand total, 140 in parts, $150 to round off. so there charging you $650 for what is listed as 2.1 hours i believe, ill have to find my recipt. my place even called me to ask if i had my old gasket because i tried to fix it the night before, without luck, and switched the gasket. they said the oem ones were re-usable, but my new one wasn't, so they were trying to save me $50, talk about great service!

eldorado1
09-11-04, 04:46 PM
I'm bumping this back up to the top, because I think I might be experiencing the same problem... I'm suspecting the solenoids may be intermittant. I'm going to try manually grounding the shift solenoids through the gears with the tires in the air to see if it actually gets through all 4. Right now it seems like it's stuck in 2nd, and it might shift to 3rd, but not 4th or 1st. or maybe it's 2nd and 4th that works, and not 1+3... I don't remember.

btw - how hard is the job? (for a DIY mechanic?)