Automatic Transmission Problems: Audi A4 01N AFN (Solution)

Hello!

Unfortunately, I haven't found a solution to my problem with the automatic transmission in any forum, but I believe I've found the best place to post about it here.

My VW Passat TDI 1.9L 81 kW (AFN) – Automatic transmission, 4G type 01N - manufactured in 1997, currently with 196,000 km.

At a mileage of 165,000 km, the following problems occurred:
Between 1800 and 2400 RPM in the 3rd and 4th gears, at a constant speed, there is a pulsating engagement and disengagement of the torque converter. (RPM fluctuations of 150 RPM). A noticeable jerking of the clutch is also felt, as well as a sudden disconnection of the torque converter starting at approximately 3800 RPM under full load.
Error code indicated: Faulty torque converter coupling!

VAG workshop recommended a new transmission (a consumable part like an oil filter? But unfortunately, it's too expensive!).
So, VAG is dismantling the transmission. Automatik Berger GmbH in Oberostendorf (a great company) is rebuilding the transmission, including a new torque converter and shift sleeve assembly.
VAG is building again.

And everything is perfect again, running like new.
Unfortunately, only 20,000 km , and the same problems again. I can't make it through every 20,000 km with a new one.

ATF Menge und Zustand im Getriebe sind ok , kein Fehler z. Stored in memory.

Kann es nicht sein, dass das Getriebe i.O. ist und nur wie in manchen Postings beschrieben falsche Sensorwerte oder Daten, eine falsche Anpassung einen zu kleinen Öldruck auf die WK geben? Or what?

Who can help me avoid having to replace my transmission?

Best regards from the coast.

Hein

hm...

As far as I know, the AG4 01M doesn't receive a torque signal from the EDC, while the AG5 (tip) does. There was a problem with the AG5 where a faulty coolant sensor would cause the EDC to send incorrect values to the transmission. This would result in insufficient oil pressure, causing the clutches to slip. I'm unfortunately not sure if this applies to your transmission.

Check all sensor values from the motor and transmission for plausibility.
Was the entire transmission overhauled, including the planetary gear set and its clutches? If so, you should check the oil pressure and the transmission control system. It's possible that the control unit has a fault or that there's a problem with the wiring.

CU Gremlin.

Moin Gremlin! Hey everyone!

As far as I know, all the clutch plates and friction discs have also been replaced. Automatik-Berger initially rules out a mechanical fault (which I'd also like to believe).

We entered the code "00050" (instead of the original "00000"), as described in the post "Adjusting the automatic transmission," and then topped up the ATF (automatic transmission fluid).

The transmission now shifts into higher gears earlier, and the clutch slippage is gone.
Only the fluctuations in RPM, approximately 50-80 RPM, remain, occurring during steady driving at around 2000 RPM.

Next, I will measure the cable harnesses and later the conductor foil in the transmission.

Here's a question for everyone before I take off all these costumes:
Where is the automatic control unit J217 located in the Passat B3?

I would also appreciate any further tips.


Best regards from the north.

Okay.

Hello!

I have the same car and the same problems. Furthermore, I recently had a breakdown on the highway. The transmission briefly locked up at a speed of approximately 180 km/h, and I thought the timing belt had broken, but it continued to function normally.
After approximately 2 days, the transmission switched to emergency mode. At VW, a faulty speed sensor was replaced; this sensor is located on the transmission, and after the replacement, it started working again. However, the erratic behavior remained (the engine speed regularly jumps during driving from approximately 2000 to approximately 2100 RPM and then back to approximately 2000 RPM). This is also accompanied by irregular vibrations.

No further errors were detected by VW, and they don't know what's causing the issue. The transmission appears to be okay. If you find the problem, please post here what it was.

I intend to sell the car because of this. I won't own another VW; it would be a shame, but I don't want to be confronted with such problems again. The repairs are extremely expensive, and the cost of repairing a transmission failure is simply unaffordable.

I hope it's just a faulty sensor, but which one? How do I check it?

Hello!

The problem I had was (ONLY!) coolant in the automatic transmission fluid.

"It's unbelievable that no one thought of this before. After the transmission has been rebuilt, with a new torque converter, a new transmission control unit, and after testing the entire electrical wiring, running the entire "jerking" assistance program, and even disassembling, cleaning, and adjusting the quantity valve, no one bothered to take a close look at the ATF fluid – as if it couldn't possibly be the problem!"

A leak in the shared engine and automatic transmission fluid (ATF) cooler contaminated the transmission oil.

The formation of steam bubbles and the deposition of glycols on the brake and clutch linings led to the problems described above.

It can be identified by a milky discoloration in the automatic transmission fluid and white-reddish deposits in the coolant reservoir cap. There is also a slight coolant leak.

A new cooler and a thorough flushing of the transmission can help if the damage isn't too severe.


Okay folks, bye.
I hope this doesn't happen to you!

Okay.

Great, thanks for the feedback!