Transmission problems

[CLN]

Hi all, I am hoping someone can help me, my 96 Eldorado has 96 thousand miles and it has started to come up with the service engine light and the statement service transmission and then the car will begin to shift hard, it mainly happens in rush-hour traffic in the mornings but now it is also after a long run at 60 or so mph and a long slow down. after the car sits for awhile the light and service engine indicator will go off and the car will run fine again.

But as I said it is intermitting, it does not happen every day but is becoming more often, two times a week either in rush hour or on the slow down, please help!!!

I have had too many bad experiances with transmission shops so would like some input before I take the car in for service.

[95SevilleSLS]

Does it whine also?

I had the exact same problem with my Monte carlo. Turned out to be a boost valve leaking. $800 fix. What's happening is your transmission is slipping and the computer, in order to stop any excess damage, increses the fluid pressure in the tranny. I didn't think the 4T80Es had any problems with that, but I guess it's possible. The 4T60Es, which is what was in my Monte Carlo, were very troublesome for hard shifting from the pressure control solenoid and the boost valve.

Check your codes and post them on here so that we can see what they are.

HOW TO "ENTER" DIAGNOSTIC MODE

To enter diagnostic mode, proceed as follows:

Turn ignition "ON." Engine can be either OFF or RUNNING.

For cars equipped with the Digital Instrument Panel Display (Digital IPC):

Simultaneously press the "OFF and "WARMER" (red) buttons on climate control center (CCC) until all display segments (IPC and CCP) are illuminated

For cars equipped with the Analog Instrument Panel Display (Analog IPC):

Simultaneously press on the Climate Control Panel (CCP) the "OFF" and "PASS WARMER" (up arrow) buttons.

After the segment display test, the driver message center displays all set DTC, current and history, in the following order:

PCM DTC

IPC DTC

ACM DTC

SDM DTC

TCS DTC

PZM DTC

IRC DTC

RFA DTC

CCP DTC

MSM DTC

MMM DTC

PHN DTC

The RSS, CCP, MSM, MMM and PHN DTC appear only on vehicles equipped with these options. Press the FAN DOWN button in order to bypass the DTC display.

On the OBD II cars, the prefixes you'll see are: "IP" for the IPC instrument panel; "AC" for air conditioning module; "TC" for traction control; "RS" for the road suspension system; "SD" for the air bags; "PZ" for the body control module; "CC" for the cell phone; "RF" for the integrated radio system.

HOW TO "EXIT" DIAGNOSTIC MODE

To exit the diagnostic mode anytime during the test, depress the "ECON" or "DEFOG" button, or turn the ignition switch "OFF."

Hopefully it's not something bad!

[BodybyFisher]

Hi all, I am hoping someone can help me, my 96 Eldorado has 96 thousand miles and it has started to come up with the service engine light and the statement service transmission and then the car will begin to shift hard, it mainly happens in rush-hour traffic in the mornings but now it is also after a long run at 60 or so mph and a long slow down. after the car sits for awhile the light and service engine indicator will go off and the car will run fine again.

But as I said it is intermitting, it does not happen every day but is becoming more often, two times a week either in rush hour or on the slow down, please help!!!

I have had too many bad experiances with transmission shops so would like some input before I take the car in for service.

I have a 96 Deville with 95K miles and I get the same thing, its the ISS SPEED SENSOR, those are the messages and symptoms I get, when my P0717 sets. You probably will find a code P0717, check the codes as noted above...

[WarrenJ]

I had the same problem with my '95 Eldorado before its Viking Funeral. Clearing the code would make it go away for a while.

A friend reseated the 20 pin electrical connector on the transmission and that seemed to resolve the problem.

When the code is set for a bad Input Shaft Speed sensor, the tranny goes into a "protect" mode wherein the fluid pressure is raised resulting in *very* hard gear shifts.

If reseating the connector doesn't help, I'm afraid you're in for an expensive repair. "BodybyFisher" (above) is in the midst of just such a repair.

Regards,

Warren

[BodybyFisher]

And yes, I agree that the first thing you should do is clean and reseat the transmission connector. When I disconnected mine yesterday, coolant was in and around it, I have not looked close enough yet to see if the pins were affected. I will report what I find later this morning. I believe my crossover gaskets are leaking into that general area, and it's possible the connectors have been affected by that.

Before I reassemble the electrical harness, I plan to spray electrical contact cleaner into every connector.

[CLN]

Thank you all,

I did get the codes and it was P0717, this an expensive fix?

However I will see about the connection first.

[BodybyFisher]

Thank you all,

I did get the codes and it was P0717, this an expensive fix?

However I will see about the connection first.

Definately detach the connection, spray it with contact cleaner and re-seat it. The repair is about $1500 at the dealer, the carriage must be dropped. That is if you can get the dealer to do the repair, they really don't want to do it, they want to rebuild it. The part is only $30, but the labor to get to it is $$$$, supposedly they say its a 10 hour job plus parts (filters, seals, sensor, fluid, etc). I have driven with this code coming on and off for about 8 months. It seems to come on when the engine is hot, if you turn off and start the car three times it usually clears the code, assuming its not current.

I am in the process if doing this job now on my 96 Deville, you can watch how it goes, here is the thread:

http://caddyinfo.ipbhost.com/index.php?showtopic=13481

I am going to start this job up again on Friday, Mike

[vikikul]

I am not a car expert but I had a similar problem where it was hard to shift and one day it did not shift at all just stayed I believe on the first gear. We tested and it was some sensor. We actually brought it to the dealership to fix it, since even though my husband could fix it Cadillacs are hard to work on without special tools and time consuming and it did not worth to mess with it. We actually have 93STS. I am not sure if your car the same.

It probably was about 100K miles when it happened and we were told that all these cars older than I believe 1997 have this problem, since the sensor was made from some bad material and almost all of them go through this repair. After the fix I had no problems with the transmission. It was about $1,200 I believe.

[BodybyFisher]

I am not a car expert but I had a similar problem where it was hard to shift and one day it did not shift at all just stayed I believe on the first gear. We tested and it was some sensor. We actually brought it to the dealership to fix it, since even though my husband could fix it Cadillacs are hard to work on without special tools and time consuming and it did not worth to mess with it. We actually have 93STS. I am not sure if your car the same.

It probably was about 100K miles when it happened and we were told that all these cars older than I believe 1997 have this problem, since the sensor was made from some bad material and almost all of them go through this repair. After the fix I had no problems with the transmission. It was about $1,200 I believe.

You are probably talking about the shift solenoids, that was common before 1996, when they were designed with an improved support bracket to stop cracking. If I had the shift solenoid problem I would have fixed it, that is a relatively easy job, the ISS sensor is a very hard job in comparison.

[rmac-etc]

It should be pointed out that the ISS problem is something that can be lived with. I have had occasional hard shifting and, yes, I do have the ISS code being set, but I have had this condition for ~3-4 years and the car is approaching 160k.

The hard shifting was very frequent at first, but rarely happens now ...

This is the first I have heard of the problem possibly being the connector ... I will find it and check that out.

[BodybyFisher]

It should be pointed out that the ISS problem is something that can be lived with. I have had occasional hard shifting and, yes, I do have the ISS code being set, but I have had this condition for ~3-4 years and the car is approaching 160k.

The hard shifting was very frequent at first, but rarely happens now ...

This is the first I have heard of the problem possibly being the connector ... I will find it and check that out.

While that is true, what I don't like is that it disables Overdrive so at highway speeds you are running at 2300 RPM rather than 1700 to 1800 RPM so you are burning more gas and the engine is working harder than it should. In addition, if that code comes on during my state inspection, I fail..

My connector did not have dampness inside by the pins so I don't think the connector was my problem, it had dampness on the outside from leaking coolant.