Audi A6 trans-error, stuck in 2nd gear

[HP]

I have a Audi A6 with 2,6L V6 from 1995
Just bought it to use over the winter, and i knew about the transmission problem, got it for $500 so i took a chance to fix it, or sell it in parts.

First off, i do not have read the error codes yet, the car is still a couple of hours away from me.

The issue
Sometimes it wont shift up to 4th gear.
All other gears is working OK, smooth and nice.
If the 4th gear works, sometimes its not shifting down to 3rd, i have to use the lever to put it in 3rd (work auto too, but its late downshifting).

When driving on the highway and it refuses to gear to 4th, i

Topic

[EricTheCarGuy]

You’re right about checking for codes first because transmission problems these days often involve either an electrical or mechanical problem, if you don’t have any codes than you may not have an electrical problem. If the problem proves to be mechanical you’ll have to overhaul it to replace whatever broken or worn parts inside the transmission that are causing the problem. I suspect you may have a mechanical problem as it seems to only be one gear that is effected, most times if it’s a shift solinoid it will effect more than one gear. Keep us posted on what you find.

[HP]

I have ordered a VAG scanner from Ross Tech now (VCDS) and waiting for it next week.

I have checked all connections, at the TCM i got a 35 OHM resistance on solenoid N92
But, if i measure the same pins at the connection on the gearbox, all solenoids comes out within the specs, 1-5 ohm, and mine are 4,2 ohm.

ATF Fluid is 2 weeks old, new filter and new fluid at Audi/VW dealer.
Noticed that i can check temperature and levels with VCDS later too, so i can double check that the work is done right 🙂
And also check condition on all solenoids, will save me alot of money.

The VAG shop wanted $75 every time they read out and cleared the codes.
I got the VCDS kit for 550 USD, well spent money.

I will update the thread later when i find anything, maybe it can be used for others with same errors.

[jacobnbr1]

I’ve seen a conductor strip act just like that.

[mobcittty]

From my experience with VW/AUDI products they all have the problem of weak automatic trannys. I will check the ATF fluid first. Maybe do ATF flush with new filter. If your car does not shows a check engine does not mean it will have one set pending. I will suggest you to find somebody who have a VAG scanner or if you are into VW/AUDI car buy it. They are not that expensive. Here is a link of a Company that sells ineterfaces you can connect to your laptop or desktop and provide an indepth scanning capabilities. (http://www.ross-tech.com). Good luck!

[EricTheCarGuy]

Quoted From jacobnbr1:

I’ve seen a conductor strip act just like that.

Interesting, thanks for that tip Jacob. Keep us posted on what you find, I’m curious to know if this turns out to be an electrical problem or a mechanical one.

[HP]

Got my Vag-com/VCDS earlier this week.
Cleared all codes, didnt bother to save them, they were atleast 5years old.

Started the car, and i have driven it since tuesday without any problems, gears up and down in D, and shifts as it should in 3 and 2.
I noticed sometimes it was a little slow to gear down from 4 to 3, but i just used the shifter and did it myself.

No fault codes.

So today, i took the car out to the woods and my intention was to annoy the system to the point where i get a fault code on the gearbox.

Dude
I had so much fun i almost pee in my pants, 4×4 on wet slippery gravel roads V-)

Now i got a code
00652 – Gear Monitoring
27-10 – Implausible Signal – Intermittent

Now its back to shifting 1-2-3 and not 4.
Touch a little on the key, and bam, in goes 4th gear

So… back to the garage
This signal, where do the TCM get it from, is it the engine or the transmission ?
Or is it alot of different signals it put together

I

[EricTheCarGuy]

Good job helping to nail down the problem. Unfortunatly I’m at a loss myself as to where to go next but if it were me I would be looking to get my hands on the service procedure for those codes, I’m wondering if Jacob has access to them.

[HP]

After a little searching, Ross-tech had them on their site. (inserted below)

So, i have ordered a new VSS (viechle speed sensor) and a new gearbox speed sensor, total $83 with next day delivery.

I had read about the F125 sensor, and i do not want to change that one. Hope it stays on the sensors as the gearbox is allright when no limp mode.
And problems changing gear up-down, i hope this is related to the sensor for engine speed. It sounds logic to me, but hey, i have seen alot of strange stuff that are far from logical in cars.

I

[jacobnbr1]

Engine Control SystemTrouble Code Chart

[dreamer2355]

Thanks for the post Jacob!

[Trcustoms719]

Hey Jacob,
Would that chart apply to a 98 A4 1.8 awd?

[HP]

Done some more testing.
Oil is checked and is at correct level.
This is so strange, it gears up and down very nice, no slippage, no hard shifting, soft and smooth, but only first time after i remove the error codes.

I have found that the error code is put when i brake to a complete stop from 4th gear. (not always, but 50% of the times)
I can feel it stays in 4th when i brake and then it goes down to 2nd hard, this is where the error code is set.

Something tells me that the indication from the brake to the transmission is failing so it dont know wich rpm the engine are at.
When i apply the brake, i can feel and hear something around the shifter making a “click”, almost like its not tightened firmly and have a little “play” when i press the brake.

Also, Audi has a warning light for the brakes, this is flashing on my panel, i have thought its about the “wear indicator” for the brake pads, but now i think it may be something regarding this error.

Except for the gear monitoring i only have a error code on the oxygen sensor, so nothing tells me anything where to start 🙂

Anyone know anything more about this?
Going to open up the consoles and take some photos tomorrow and see if i see anything loose or not tightened.

[EricTheCarGuy]

It’s beginning to sound like a mechanical issue like perhaps a shift valve or something is sticking in the valve body. You may have to do an overhaul in order to remedy the problem. Keep us posted.

[HP]

My adventure is going strong 🙂
I have noticed that i do not need to remove the error code, if i let the car off for 2-3 minutes, i can drive again and all gears works perfect. Until i brake hard so it jumps from 4th-2nd.I have bought a usb cable so i can drive and log whats happening.

I also have noticed that it isnt when i brake the problem occurs, its when i brake hard and after that accelerate from zero.It shifts one time, then i can se on the RPM roughly about 2000rpm it jumps 100rpm and continues to accelerate without changing to 3rd.
Its stuck like this until i turn off the car and start it again.
So it must be when this happen the error code is put.

If anyone have any tips or trix, im happy to receive them in my adventure 🙂
I will hunt this problem down just to know, and learn.
May be cheaper just to change transmission or valve body, but learning is not free either.

Next up is to change the speed sensor located on the left drive axle.
I also going to change the “drive joint”, dont know the english word for it. When i turn left i can hear tick-tick-tick-tick from the joint, that one 😉 I have read some having troubles with this bad, and i need to change it anyways.

Got it for $500, so i can put 500 more in parts and stuff to get a decent winter car. Got two kids so i want to drive safe.

A little pic on the “beauty”, well, almost, little work on the body to do but first transmission error 🙂

[EricTheCarGuy]

Cool thanks for posting the pic. Given that you can shut it off and restart and the problem goes away I think it’s fairly clear that it’s an electronic issue, it’s hard to say if it’s due to the computer getting bad information from somewhere, if you have a bad component like a bad solinoid or something, a problem with the wiring or a connector, or a problem with the computer itself. Especially if you think the car might have been in a collision at one time it’s not a bad idea to check around all the wiring to see if you find any damaged areas, the symptom of it only happening during hard braking makes me wonder if something is making contact with a body component at times and shorting out, you might also try ‘wiggeling’ the wires while the engine is running just to see if you can cause a change or make the light come on.

[Author]

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