95 Eldorado Shift Problems

[dcsj]

Hi,

First time posting here. Last Friday my wife was coming home from work with the cruise ingaged at 60, when suddenly the engine reved from 1600 rpm to 4000. she disenged the cruise imediately. She said, it felt like something happened to the transmission. She drove the rest of the way home (6 mi) at 35 - 40 mph with the engine revs at 3500-4000. She called me immediatly and told me what happened. When I got home we took the car for a short drive uptown the problem did not repeat during that drive. I took the car for a short drive on Saturday, on my way home the problem suddenly appeared. It was as if the car suddenly shifted into neutral. The car was rolling at 30 mph and felt the gas pedal get light as if it was accelerating with the cruise engaged (it was not) But it seemed to be in second gear and would not upshift or down shift. After I got back home I did some around the block driving. I determined it would shift from 1st to 2nd but no higher. After searching throught some of the threads it sounds like an A or B soleniod issue. I did some research here on how to retrieve the codes. This is what I have PO29,PO39,PO94 and PO117. According to the trouble codes guide this is what they are

PO29 Transaxle shift 'B' soleniod problem ( 1st,3rd,4th gear)
PO39 TCC/VCC Engagement Problem.
PO94 Transaxle shift 'A' soleniod problem (VSS)
PO117 Open/Short Soleniods/Soleniod wiring (Transmission)

The PO39 issue has been known for a long time but never seemed to cause any drivability or shift issue so we did not bother it.

My guestion is if the PO117 would cause the coding of the Soleniods.

If it is determined to be the Soleniod issue, does anyone have an idea what a dealer would charge to replace them?

I have been reading that you should not have to drop the tranny to fix this but that some dealers will tell you that you do. I want to armed with the appropriet info to challenge them if they insist on doing this. Normally I am a diy'r, But I don't have the time to do this one.

Thanks for any help in advance.

Dennis

[JC316]

It sounds like your car defaulted to second gear due to the electrical connection loosing contact.

You need to check the connection. If you are looking head on at the car, it's at the front, near the radiator. You will probably have to get under it to see, but a bunch of wires come out of the transmission and go to another bunch of wires.

You will need to pull the connector apart and look for corrosion.

[dcsj]

Thanks, I'll give that a look. It would be a miracle if it was just that simple. Fingers are crossed. I will post back with the outcome.

Dennis

[JC316]

Those three codes are all dependant on the wiring harness, so if the harness looses contact, it will fire off those codes and default to second gear.

Logicly, there aren't many more options, especially since that is a common problem on these cars.

[dcsj]

Took the car into the dealer first thing this morning. I gave him the same info I discribed here. Along with the suggestions. He claimed that if you have to go in to change the soleniods, your better off changing all of them as a prevetative measure. I don't know what he means when he says ALL. I'm don't know how many there are to begin with. His concern, was that the car should have defaulted to manual shift mode based on vaccuum. I told him that in my local street driving I didn't rev the engine beyound 2500 rpm. He said it should manually shift off vaccum at around 3500. But the way I see it the transmission only shifts via electronic signal as in an electronic vaccum signal. So, I'm falling back on the PO117 theory at this point. Btw I did look up under the car for the wires you mentioned earlier. The problem is the subframe doesn't allow me to get my big hands on them. It appered as if there where several connections and I was not sure which one to look for. Either way, it's in the shop now now and they said they should be able to get at it later this morning.

Dennis

[acklac7]

Originally Posted by dcsj

Took the car into the dealer first thing this morning...... He claimed that if you have to go in to change the soleniods, your better off changing all of them as a prevetative measure.....His concern, was that the car should have defaulted to manual shift mode based on vaccuum.

Dennis

Funny he didn't mention trading it in on a "new" Cadillac....If it were my car I'd get it out of there ASAP! Especially if he suggests changing anything other than the A. and B. solenoids. It sounds to me like he wanted to change every possible solenoid in the Trans., which would mean dropping/tearing it apart. I would clarify what "changing all of the solenoids means" if it means dropping the tranny to get to the pressure control solenoid etc. then I would high-tail it out of there......And file a complaint against the dealership.

And IMO the service advisor either A. doesn't know what he's talking about or B. knows what he is talking about and is trying to BS you into thinking Tranny is toast.....The whole "shift on vaccum" bit is laughable...If the computer isn't registering the connection(s) to the solenoids it won't shift out of second...Period. There is no "manual shift mode" The tranny will shift from 1st-2nd, then try and shift out of 2nd..if the solenoids don't fire it will just stay in second....I would seriously comtemplate taking your business elsewhere (like an ATRA certified Tranny shop )

[z06bigbird]

Originally Posted by dcsj

Took the car into the dealer first thing this morning. I gave him the same info I discribed here. Along with the suggestions. He claimed that if you have to go in to change the soleniods, your better off changing all of them as a prevetative measure. I don't know what he means when he says ALL. I'm don't know how many there are to begin with. His concern, was that the car should have defaulted to manual shift mode based on vaccuum. I told him that in my local street driving I didn't rev the engine beyound 2500 rpm. He said it should manually shift off vaccum at around 3500. But the way I see it the transmission only shifts via electronic signal as in an electronic vaccum signal. So, I'm falling back on the PO117 theory at this point. Btw I did look up under the car for the wires you mentioned earlier. The problem is the subframe doesn't allow me to get my big hands on them. It appered as if there where several connections and I was not sure which one to look for. Either way, it's in the shop now now and they said they should be able to get at it later this morning.

Dennis

As I recall, there are 2483 solenoids on your car related to the shifting. Good news is that they are only $300 each.

LOL

Wish you best of luck with your troubles. Hope I did not give you a heart attack.

[dcsj]

And IMO the service advisor either A. doesn't know what he's talking about or B. knows what he is talking about and is trying to BS you into thinking Tranny is toast.....The whole "shift on vaccum" bit is laughable...If the computer isn't registering the connection(s) to the solenoids it won't shift out of second...Period. There is no "manual shift mode" The tranny will shift from 1st-2nd, then try and shift out of 2nd..if the solenoids don't fire it will just stay in second....I would seriously comtemplate taking your business elsewhere (like an ATRA certified Tranny shop )[/quote]



Thanks for the info. It makes complete sense and is what I was thinking. thanks for confirming it. Unfortunately the service writer is kind of a friend of a friend relationship. This is why I wanted to be armed with as much info as possible. I'd rather be an informed customer than be treated like some schmoe that walked in off the street. As for the vaccum thing, I can curtainly see him get the transmission types confused and give the wrong info. They are a dealership and see lots of different transmission models. Also there aren't any exclusive tranny shops in town as an alternate.


What is the sequence of events and components that do the shifting? Or how do the components fire for each stage of shift? If Soleniod "A" drives the shift from 1 to 2 and soleniod "B" drives 3 to 4 What drives 2 to 3?

Dennis

[JC316]

You don't go into the transmission to check the harness. It comes out of the tranny and connects under the car. You can get to it from the top as well, but I found it easier to go under.

I highly doubt it's the solenoids, mainly due to the PO39 and PO117. Those are all on the same power connector that comes from the wiring harness.

Ok, if you look right against the firewall, near the coilpacks, you will see a big bundle of wires. If you follow that toward the drivers side of the car, it will go down and cross over the transmission. Continue following it and it will take you right to the connector.

Also, make SURE that no spark plug wires are sitting on that bundle, mine were transfering spark and giving the same sort of symptoms as yours.

[dcsj]

Is it an inline circular shaped connector with a gray body about 1.25 inch diameter? I found this connector just to the driver side of the front engine mount sitting in a small open area just above the sub frame. Or, is the connector you are talking about plug directly into the transmission? The car is at the shop right now. But, I'm thinking of going in and checking up on it. With more ammunition (info)if you know what I mean. Thanks for the spark plug wire tip I'll pass it along. I changed the plugs and wires a year ago, and tried to do my best at routing the wires right where the originals had run. Btw, at the time the car started missing pretty good. For some reason the back side plugs were really worn but the fronts not so much.

Dennis

[dcsj]

Just got back from the dealer. What they have done so far is checked the transmission harness connector. It appears to good. They dropped the pan and pulled the soleniods and bench tested good. checked all internal ground points for continuity. They said, the the fluid was clean as could be with no fillings or lining particles of concern. All in all it looked real good. They put it all back together and test drove. It still won't shift. He said they had a call into GM engineering to see if they could swap PCM's with another car for verification of whether that may be the problem. While they are waiting for that info. The next step was to check the upper harness once the engine had cooled down from the last test drive. They are workng on it in between other jobs.

He also said, after resetting the codes. None of them have retripped in the tests drives and that they had used the hand held control unit to manually overide the shifting but it still wouldn't shift. Dones that make since?

Dennis

[JC316]

Originally Posted by dcsj

Just got back from the dealer. What they have done so far is checked the transmission harness connector. It appears to good. They dropped the pan and pulled the soleniods and bench tested good. checked all internal ground points for continuity. They said, the the fluid was clean as could be with no fillings or lining particles of concern. All in all it looked real good. They put it all back together and test drove. It still won't shift. He said they had a call into GM engineering to see if they could swap PCM's with another car for verification of whether that may be the problem. While they are waiting for that info. The next step was to check the upper harness once the engine had cooled down from the last test drive. They are workng on it in between other jobs.

He also said, after resetting the codes. None of them have retripped in the tests drives and that they had used the hand held control unit to manually overide the shifting but it still wouldn't shift. Dones that make since?

Dennis

Well......crap. Mine was doing the same thing and it turned out to be the 2-3 accumulator spring being broken in half. That is pretty major and requires the removal of the transmission to get at it. I just replaced my tranny when it happened.

Oddly enough, mine is a 95 too.

[dcsj]

Well, things are starting to get pretty bleek at the momment. They checked out the upper harness and it checks out. PCM too. They did a complete diagnostic run driving the car and faxed the results to GM to get their analysis. He did say that the PCM is telling the system to shift when it should but nothing is happening and he said the pressures in the 3rd and 4th gear. servos seem to be below spec. He said it could be that maybe there is some debrie under a check ball. He said, that we could take it too a local oil change place and try and have the system reflushed. I had it don't last summer. He they don't flush the systems anymore at there shop. They only do pan drops and filters. he only suggested it because it would be cheaper than them opening the valve body. But I'm thinking wouldn't they have had to open the valve body in order to have checked the soleniods? At least thats what I have been reading. The soleniods are inside the valve body, correct? Something seems odd.

Dennis

[JC316]

A clogged checkball is possible, especially since you had it flushed before. Flushings can sometimes cause that.

It could just be that the solenoids are shot, are they opening properly? The solenoids are very common and could be the culprit. I changed mine, only to find out that the accumulator was bad. I got mine like that though, so I have no idea when it went out, if yours was shifting, it's probably just the solenoids.

[dcsj]

Thanks for the moral support, I'm tring to keep a positive attitude about the whole thing. I'm going to go back to the dealer tomorrow, too just verify how they checked the soleniods. Possibly make them replace them just to know they are good. $50-$60 for the kit is nothing compared to the worstcase senario.

I sure wish there was a link here with some pictures detailing the replacement process.

Dennis