Tiptronic problem with torque converter

Hello everyone!


First, here are the basic details of my car: It's a Volkswagen Golf IV Variant. First registration: 12/2002, Mileage: 87,000 km, Engine code: ATD, Transmission: 5-speed Tiptronic, Gearbox code: FST.
I would also like to know if it's a Jatco or a ZF transmission.

The problem:

When starting from a complete standstill, there seems to be a brief interruption in the power transmission within the gearbox.
I release the brake and press the accelerator. The car rolls forward a few centimeters.
Then the power transmission is briefly interrupted, only to resume with a sudden jolt.
You can practically feel the power being abruptly 'dumped' into the drive systems.
The whole thing probably happens within a quarter to half a second.
This creates two 'start-stop' sequences.

Most of the time, the transmission behaves normally. Then, again, the problem reappears.

The effect is particularly noticeable when starting with a heavy load (e.g., starting uphill or with a fully loaded vehicle).
Even when driving on a flat surface or with a light load, you can still feel it, but very subtly.

I would actually rule out a problem that is dependent on the seasons, since the problem has occurred now and also in the summer.

I read somewhere on the internet that there's a known issue with VW vehicles called 'torque converter running dry' ????

I'm not sure if anyone ever actually checked the ATF during the inspections.
The previous owner drove the car extensively, primarily on the highway. Almost 90,000 kilometers in just under two years.
Could it be that, despite being 'lifetime-fill,' it might still need to be replaced at some point, or that the fill amount might not be correct?

Unfortunately, the last inspection was not carried out by a VW-approved workshop, and the dealer has already informed me that...
It looks like the warranty on the transmission is not very good...

Before I pay to have the VW transmission checked, I'd like to hear what you have to say about it first...

Steve.

'Converter running dry' means that the converter has run out of oil after being idle for a long time and therefore needs to be refilled. After the engine starts, it may take some time before power transmission is restored. However, this issue should disappear within a maximum of 30 seconds of engine running.

Changing the oil is always a good idea and highly recommended!

Please check the plausibility of the temperature sensors for the engine and transmission.

CU Gremlin.

Thanks, for now. That's something, at least.

I've noticed that the Wandlerbrücke (torque converter lock-up) doesn't engage immediately with the 5th gear. Usually, it takes 5-10 seconds. When I release the accelerator, the engine speed drops immediately to idle. I suspect this is due to the dynamic shift program. Is that normal?


Are you referring to this issue? I will bring it to the attention of the dealer.

Okay, I'm ready. Please provide the German text you want me to translate.

'The transmission control unit has a fault code indicating 'gear monitoring, incorrect gear ratio,' and the engine control unit has a fault code indicating 'coolant temperature sensor - G62, intermittent.' The automatic transmission may already be experiencing shifting problems in the 4th or 5th gear.

The coolant temperature sensor occasionally detects a temperature that is much too low (e.g., -4°C instead of 60°C). As a result, the engine control unit calculates a much too low (incorrect) engine torque, which is transmitted via the CAN bus to the transmission control unit for ATF pressure calculation (e.g., calculated: 20 Nm, actual: 190 Nm). The clutches are then held with insufficient pressure, causing them to slip. This primarily damages clutch E, which is used in the 4th and 5th gears. 'The gear is responsible for power transmission.'

I once noticed that the Wandlerbrücke (torque converter) doesn't lock up immediately with the 5th gear. Usually, it happens 5-10 seconds later. When releasing the accelerator, the RPM immediately drops to idle. I attributed this to the dynamic shift program. Is that normal?

@ SteveH
I'm experiencing the same problem right now. Could you tell me where the problem was on your end?

Regards,
Dieter.