1995 A3 Jetta - Automatic Transmission Problems

Hello all ...

My daughter's '95 A3 Jetta's automatic transmission has been acting up recently. If you put it in "D" it seems to slip through first and into second. You can manually shift through the gears without a problem.

I had it put on the vag-com last week-end and there weren't any codes. I took it to my mechanic of 20 years and he test drove it and pulled the codes. It's throwing codes for the #1,3 & 5 selenoid, but the selenoids are working correctly. The transmission was overhauled by him when I bought the car: new valve body, selenoids, wiring harness and TCM. The clutches were like new and all fluid was replaced with the VW stuff.

The radio loses power from time to time. I saw on-line that somebody was experiencing similiar problems and it turned out to be a problem with a wire that was spliced into the 24-pin wiring harness that attaches into the instrument cluster.

Has anybody dealt with any issues like this before? Is there a wire, sensor, etc. that's prone to messing up the transmission shifting?

Thanks in advance for any and all help!

Reply to
tombstone
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Correction to previous post:

I saw on-line that somebody was experiencing similiar problems with the transmission and it turned out to be a problem with a wire that was spliced into the 24-pin wiring harness that attaches into the instrument cluster. Her radio loses power from time to time - I'm wondering if there is any connection.

Thanks Again!

Reply to
tombstone

Make sure that the trans harness plugs are dry and tight while making sure the terminals are also clean and tight. Possibly the harness for the Vehicle Speed Sensor for the Trans Control Module might have a wire broken. You might be able to check the connections and sensors/switches from the TCM plug. What kind of codes is it throwing for those solenoids?

Radios, and I have repaired 3 or so, usually have a problem with bad solder joints on the inside of them. The bad solder causes a short which can either briefly turn the radio off or can cause it to go to SAFE.

later, dave (One out of many daves)

Reply to
dave AKA vwdoc1

Thanks for the input!

I'm not sure what codes it was throwing for the selenoids - I'll need to get ahold of my mechanic and double check.

If the vehicle speed sensor isn't working or has a bad wire would the spedo work? I'm not too familiar with these cars and need to pick up a bentely manual. Where does the speed sensor mount?

The radio problem that you described is exactly what is happening. Sometimes it will go off and not come on for days, only to return in safe mode. We're going to be replacing it soon so it'll be a non-issue. For future reference can the radio be opened up and resoldered?

Thanks again!

jeff

messagenews: snipped-for-privacy@48g2000cwx.googlegroups.com...

Reply to
tombstone

replies within.

Sometimes the codes along with the complete info about the codes helps find the problem easily.

AFAIK The trans should have 2 VSS, one for the speedo which is closer to the firewall over the final drive and the other for the TCM which is closer to the battery. Not totally sure on this though. Your Bentley should identify them for you.

Yes I think someone has described the radio repair procedure online, but I am not sure about that. Should be about a 15 minute repair to resolder that bad connection once the radio is out of the vehicle.

Reply to
dave AKA vwdoc1

Well the car has been in the shop for going on a month now ...

The problem was hard delayed shifting into first from a stop. After you were rolling all was good.

My mechanic trace the wiring from the TCM to the transmission and checked it for continuity - all was good. He thought the valve body may be bad and I had that shipped out and tested - it came back absolutely fine.

So I'm at a loss now ....

There are two more things I'm kicking around: (1) I've read that a bad MAF can cause the transmission to act weird (2) a clogged trans cooler may cause it to act up.

Does anybody have any more info on this? Things to look at?

How can I double check to make sure that my trans has the TCM that is supposed to be with it?

Thanks a bunch!!

jeff

dave AKA vwdoc1 wrote:

Reply to
tombstone

Hmmm I was wondering what was happening. Thanks for including all of the posts to refresh our minds. ;-)

Does your mechanic, or anyone close to you, have the ross-tech.com vag-com tool/scanner that can plug into the transmission and engine control modules to see what is happening? That scanner should also tell you what the TCM's part number is without you manually looking on the module. On my module there will be part numbers then above them a 2 letter code IIRC and that should be what you need for the entire part number.

Can you get the fault codes that are stored and post them here? Post all information about the codes. I think you said something was wrong with the solenoids in the trans valve body.

So does it seem like it is starting in 2nd gear from a stop?

My money is still on either the wiring or sensors. It could be just some loose terminals or some moisture in there.

later, dave (One out of many daves)

Reply to
dave AKA vwdoc1

Back with more info and questions ....

I found out that my mechanic uses a Snap-On computer thing to read the codes and stuff. He states that it does the same as the VAG-COM, but I'm not 100% sure about that.

I'd like to pick up a VAG-COM program and the connector. I looked at ROSS, but have no idea what I need and was looking for guidance in that department.

There are absolutely no codes according to the Snap-On thingy. The wiring had been traced and comes back fine. THe valve body was shipped out and tested fine. I've had the transmission cooler swapped out and it didn't make a difference.

I haven't driven the car for a while, so my recollection of details may be lax ... but it seems to start in first gear fine then engages second kind of rough - like a jolt, then it's fine for all the others.

As I mentioned I saw somewhere were somebody had that problem and it ended up being the MAF sensor.

I don't feel that the problem is internal to the transmission as it was opened up and checked out prior to being installed.

Thanks for all the info!

Jeff

Reply to
tombstone

In that case it might just need a reset of the control unit.

Turn on ignition for 5 seconds, turn off, turn ignition (not engine) on again, hold gas pedal to the floor for about 15 seconds, release pedal, start car, drive on and see if that works.

Reply to
Matt B.

I just picked it up and here's the deal .... I drove it hard on the way home to see what was what.

goes into second. It seems to do the same for the other grears just not at pronounced. After you're moving, it seems to move up and down ok.

When you come to a stop and its downshifting, there seems to be a slight "thud".

The guy I bought it form put in a TCU from a boneyard and gave me a spare. The part numbers do not match but they have the same connection type. Would this matter?

If a speed sensor is shot, would that cause a problem like this? How about a bad torque convertor?

I'd love to exhaust all possiblities before we spend the cash on a rebuild only to have the same problem.

Thanks guys!

mm

Reply to
tombstone

replies also within

Now I forgot to ask....................Are you running the expensive VW synthetic fluid in the auto transmission? That is supposed to make a difference along with the correct amount of fluid.

I doubt if the Snap-On computer thing can do what the ross-tech.com tool can do, but I could be wrong! ;-) The ross-tech tool is also mentioned in the Bentley as one of the tools recommended.

You could get the least expensive REAL tool AFAIK (software $100 + tool $129)

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find someone close that will help you with their tool.Try contacting someone here
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usually don't recommend the imitation tools on ebay since they will need to activate the ross-tech software at $100 which might limit your use to only one computer and OLDER software. :-(

**************************

Now are you sure the trans starts off in first gear? If the trans is in limp mode then it could feel like it is slipping. Slippage could come from maybe low pressure? I believe you said that this transmission has been recently rebuilt??? Bad pump Or incorrect fluid type or level.

What if you drive the transmission with the TCM disconnected? Does it feel the same?

YES

Someone mentioned resetting the TCM/TCU. That is good and also look at the throttle body on the engine with the scanner to make sure that it changes it's angle smoothly. You should use the correct TCM for that transmission. Post both of the TCM part numbers including those letters above the numbers.

The speed sensor should throw a fault code, but I don't think a bad convertor would. Might be a bad torque convertor but I think it would cause a nasty rise in fluid temperature which should throw a fault code and throw the trans in limp mode possibly dropping the trans in a lower gear.

Reply to
dave AKA vwdoc1

The invoice I received has the fluid listed at $2.50 per unit and is listed as "Dextron III". I haven't checked the fluid level personally.

Than Ross Tech it is.

formatting link
or find someone close that will help you with their tool.> Try contacting someone here
formatting link
I usually don't recommend the imitation tools on ebay since they will need> to activate the ross-tech software at $100 which might limit your use to> only one computer and OLDER software. :-(>

It is definately starting off in first gear.

It was "partially rebuilt" prior to be purchasing the car. It was opened up and gone over by a transmission shop. Is there a way to check the pressures to see if it's a bad pump? If the pump is bad wouldn't it be more cost effective to put in a reman transmission?

I will do this ASAP and report findings.

I tried that last night and didn't notice a thing. Maybe I did it wrong. Key on for five seconds, key off, key on, depress gas pedal for

15 seconds, start car. Is there any visual indication that the reset was successful?

That is good and also look at the

I will get them tonight and post them.

If fluid was "leaking" back into the transmission from the torque convertor, would it cause it to slip until the fluid was pumped back into it? Would that make it slip all the time or when shifting between gears?

Reply to
tombstone

Please see additional information above ....

I double checked the invoice and I was billed for Dextron III, not the VW synthetic that should be in the tranny. I'm sure that this may have something to do with the slipping between gears.

I called a VW dealer and spoke with a tech. She said that if they drain and fill serveral times they could change out the majority of the fluid, but there would be the chance of the vehicle being immobilized due to the cleaning properties of the fluid.

Has anybody heard of such a thing? I thought I was on the way to a logical explanation to my woes and now this ....

*sigh*

Thanks again for any advice you can offer.

mm

Reply to
tombstone

I sent someone with their early '91 Passat to have her automatic transmission fluid changed. Her fluid was very dark and her transmission seemed sluggish in shifting. I got her trans electrically correct by installing a used TCM in it, but it also needed a fluid & filter change. Her early Passat would not even start with a defective TCM! She called around and found a chain transmission place like AAMCO that seemed very knowledgeable about the VW trans fluid. The shop recommended using the correct VW fluid and performed the service. All went well and the transmission seemed very smooth and responsive again. She was pleased.

I am not sure if the Dextron III is causing your problems but your trans might prefer the correct VW fluid. I have Dextron III in my late '91 Passat and after I corrected all of the electrical issues with my trans it is doing very well. Mine had been rebuild by the previous owner and currently only has 30+K miles on it.

Reply to
dave AKA vwdoc1

I'll get the transmission number and TCM number for starters. I talked to a VW specialist who said he'd do a complete flush and fill with BG Forumula 312 (fully synthetic ATF) as it's a suitable replacement for the VW G052 162 A2 for $150.00.

THe dealership said they'd do repetitive drain and fills with the VW stuff, but said that the transmission could become immobile.

I'm also going to the VW specialist on Friday to have him hook it up to the VAG COM - I'll report my findings

THanks!

JEff

Reply to
tombstone

cool! and good luck too!

Reply to
dave AKA vwdoc1

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