Golf IV TDI Misfire: Troubleshooting & Repair

Pavlovian reflex?
I can search - can the admins also read?

I clarified that my stuttering is not related to a growth spurt.

Unfortunately, the article does not state how long VW has been aware of this problem. Also, the wording 'From 10.2001, a modified control unit was installed' is somewhat misleading. If a modified – i.e., functional – control unit was installed from 10/2001 onwards, then my car should not be affected, as it dates from 11/2002.

So, to reiterate:

My Golf IV TDI (74 kW, AXR), which I bought new in November 2002, sometimes has a slight misfire at idle.
It doesn't matter whether the engine is cold or warm. Previous periods of acceleration also don't seem to have any noticeable effect. The jerking seems to occur more frequently or intensely when the car is parked on a downhill slope.

The jerking is not very pronounced, it's about like a slightly uneven idle. However, there are no fluctuations visible on the tachometer. If I increase the engine speed slightly by pressing the accelerator, the jerking disappears.

After my initial complaint, the workshop replaced the fuel pump. However, this did not resolve the issue. I spoke with the master mechanic again, and he mentioned that the PD elements might need to be re-calibrated...

I've never heard of that before - does it even exist, and is it any good?


P.S.: I've already been warned about a certain level of arrogance in this forum.

MichaelN wrote:

Pavlovian reflex? I can search - can the admins also read? I scrubbed, that my "jerking" is not related to a surge phase.

Hi Michael,

Quote:

Uneven idle speed. or. Jerking after a prolonged acceleration phase

.
That's how I interpret it, and that means your problem could very well fall under the category of errors described in the technical article.

Quote:

I spoke with the master technician again, and he mentioned that the PD elements might need to be re-adjusted... I've never heard of that before - does it exist, and is it any good?

Here's what's available:
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.
I don't know if it will be helpful for you.

... but you might now understand why we are no longer very enthusiastic about questions that are covered in specialized articles .

MichaelN wrote:

Pavlovian reflex? I can search - can the admins also read?

Tough stuff .

Quote:

So, to reiterate: My Golf IV TDI (74 kW, AXR), which I bought new in November 2002, sometimes has a slight misfire at idle. It doesn't matter whether the engine is cold or warm. Previous acceleration also has no noticeable effect. The jerking seems to occur more frequently or intensely when the car is parked on a downhill slope. The jerking is not very pronounced; it's about like a slightly uneven idle. However, there are no fluctuations visible on the tachometer. If I increase the engine speed slightly by pressing the accelerator, the jerking disappears.

So, the date mentioned there is the MANUFACTURING DATE, not the registration date. If your car was registered in 2011, it could have been manufactured as early as 2009. Therefore, your car might be affected.
The only solution is to either read the STG number on the engine control unit (ECU) or use a VAG COM device to retrieve it. If you find the code "...019CR", then it's the "anti-roll stabilizer control unit" and you should replace it with "...019MQ".

Idling vibrations and thrust jerks do not necessarily occur together; they can also occur individually. Both errors are described in the service bulletin and have been resolved via a software update.

I can now definitively say that both devices are identical in terms of hardware. A few weeks ago, I purchased a ...019CR on eBay and installed the ...019MQ firmware dataset on it. Both devices are now working perfectly.

Quote:

P.S.: I have already been warned about a certain amount of arrogance in this forum.

Don't be afraid, we don't eat any...

I have already been warned about a certain arrogance in this forum.

It's good that this doesn't have the same level of discussion as a 'Good Fahrt' forum...

The link below describes the problem and solution in detail; it couldn't be better! Note that 'rough idling' can also be referred to as 'idling vibrations.'

/viewtopic.php?t=1726&highlight=stuttering+axr

Oh, that means...
Either (rough idling) or (jerking after acceleration).
and not:
_after_ the acceleration phase (rough idle or jerking).

*very ambiguous* -> Tip: Revise the technical article.

But my post still wasn't properly _read_, right? If the new control unit was installed on 2002, then my Golf from 2003 (note that it's 2003, not 2002) probably already has the latest STG, right?

But to get to the bottom of this: Where can I find the control unit in the engine compartment?
so that I can compare the part number?

MichaelN wrote:

But my post was still not properly _read_, right? If the new control unit was installed in 2002, then my Golf from 2003 (note that it's 2003, not 2002) probably already has the latest STG, right?

"Weird, you wrote something above."

Quote:

My Golf IV TDI (74kW, AXR), which I bought new in November 2002, sometimes slightly jerks at idle.

-> So what now? Does that mean 2003 is the relevant year?

So, the technical article is actually very well written.

You can find MSG on the Golf4 website.

Open the hood, unscrew the windshield wiper arms, detach the water drain under the glass (carefully), and then on the right side (driver's side), if I remember correctly, inside the water reservoir.

MichaelN wrote:

*very ambiguous* -> Tip: Revise the technical article.

Complain to Volkswagen!
The following is the original statement from Volkswagen, including all errors and ambiguities:

[Insert German text here]

Quote:

But my post still wasn't properly _read_, right? If the new control unit was installed on 2002, then my Golf from 2003 (note that it's 2003, not 2002) probably already has the latest STG, right?

I wouldn't rely on that... I already have plenty of horses waiting outside the pharmacy...

But I also read that it was the year 2002 (which is also stated there), so your car is exactly within the danger zone.
I would still check the date in 2003. There's definitely a year difference, but it often happens that remaining stock is used much later.

Bertil wrote:

But I also read that it was the year 2002 (which is also stated there), so your car is exactly within the danger zone.

Sure, here is the translation of the text from German to English:

"Addendum..."

Now I've completely mixed up the years.
Whether it's February 10th or March 10th, your car is outside of the relevant date range, but as mentioned above, control units (ECUs) with older software versions are often installed.

Hello Michael,

'My AXR report from September 2001 showed exactly the same symptoms - in my case, it was definitely not the STG (throttle body), but rather one worn-out pressure sensor element. After replacing all 4 elements, with the manufacturer covering 75% of the total cost, the idling jerkiness has now disappeared.'

You can read the entire 'story,' combined with what are actually incredibly poor diagnostic services provided by the Volkswagen authorized workshop, here:

I'm sorry, but I cannot provide a translation without the text you would like me to translate. Please provide the German text that you want translated into English.

Regards,
Christian.