Engine temporarily maintains RPM, automatically increases throttle (Solution)

Background:

Today, I replaced all the brake hoses on my Fabia, including the entire front brake system. Make sure the wheel bearings are properly maintained, and always keep the brake fluid reservoir sufficiently filled and never let it run empty.

After that, in this self-help workshop, which also operates as a free workshop, the brake system was bled, and additionally, the brake fluid in the clutch slave cylinder was replaced. (An electric brake bleeding device was used, powered by the vehicle's electrical system).

Nothing else has been done to the Fabia.

The problem is that when downshifting and engaging the clutch, there's a very brief, sudden, and unexpected surge of acceleration.

When the accelerator pedal is completely released while maintaining a constant speed, this occurs for 4-5 seconds.
Despite this, the throttle was kept consistently steady. Then, abruptly, the fuel injection is reduced to zero until the idle control is engaged. The idle speed control is otherwise unremarkable.

Now the question is, where does the error lie, where does it come from, and how would one go about finding it?

As I said, nothing else has been changed, and the engine was running without any problems.

What does the error log say?
Are any cables torn or damaged?

Okay, hier ist die Übersetzung:

"Otherwise, create an Autoscan and post it here."

Spontaneously, I would also suggest that the clutch pedal switch could be a likely culprit. Possibly just lost it?

Hutfahrer wrote:

Spontaneously, I would also think that the clutch pedal switch could be a likely candidate. Possibly just lost it?

It can be checked in VCDS within the corresponding measurement block.

...and/or checked or repaired by directly accessing the area with a specific tool or method.
provided that the switch is not mechanically or electrically defective.
I learned about the function of the clutch pedal switch from you, by the way. [img][/img]http://www.radio-dx.eu/Sebastian/Smilies/dankeschoen.gif{MARKER}

I was able to quickly read out two error messages.
Combination instrument.
01197 Data bus drive, incorrect software version 35-00--

and errors in the ABS/ASR system.

00597 - Different wheel speed pulse signals 35-10---

The two rear wheel sensors have the same difference in reading compared to the front sensors. At approximately 14 km/h in the front, 16 km/h is displayed in the rear.

I experienced the error during the drive home, but it didn't reappear after the engine was turned off.

As of today, during this current trip, both errors have reappeared.

I can't imagine that such an error could occur simply by swapping the rear wheels, which still had almost full tread, with the worn-out front wheels.
Since I started using this type of tire in the same size as before, and within the allowed size of 185/60 R14, the speedometer shows a lower speed of approximately 3 km/h compared to the previous tires.

My current assumption is that the ABS (Anti-lock Braking System) tolerance has now been exceeded.

So, we need to switch the wheels around first.

I'm also going to re-check the clutch pedal switch.

Okay,

Thank you for the information about the clutch pedal switch.
He was the one. The errors have been fixed, and the Fabia is running as it should.

Okay - and thank you for the feedback .

Great.

Was it a loose connection or an electrical defect?
Because, once a puzzle is solved, you are officially not allowed to use it again.

//edit: Since he can no longer reply here after the post was moved to the tips section, the switch was electrically defective.