Electrical Stability Program

Hi DIY enthusiasts,

'My ESP system has been acting up lately. Here's what's happening: The car is parked in an underground garage during the day. I start the vehicle, it runs normally, but then, after a few meters, the ESP warning light comes on, even though I'm not pressing the accelerator or brake. It either turns off after a few seconds, or sometimes it doesn't. Another example: I'm approaching a red light and brake normally. The car stops, and the ESP warning light comes on. I've checked the error memory of the ABS, engine control unit, and comfort control unit, but there are no errors stored. I've also checked the connections of the ABS sensors to the control unit, but I can't find any errors there either.'

Was könnte das sein ? Who can help?

Okay: Passat 3BG, 96 kW, year of manufacture 2001.

Hi m3_bremse,

'My first G4 exhibited the exact same problem until I sold it. The ESP light would particularly come on when approaching a traffic light slowly. However, it would then remain on until the next reboot. I took it to VW three times (under the used car warranty), but they didn't find anything. In the end, I got the impression that there must have been a loose connection somewhere in the ESP system, because the light would come on after almost every bump in the road.'

Hi Marco,

The problem is that it's annoying and appears suddenly. When the ESP warning light is on, I feel like the power is reduced. That wouldn't be ideal if this system activates uncontrollably. Another thing I've noticed is that it can sometimes be cleared by turning off the ESP switch, but not always. And the most concerning thing is that the ESP switch sometimes shows absolutely no function at all! This could indicate a problem somewhere in the system, right? I've already searched through various wiring diagrams, but I haven't found anything related to this. Does anyone have a link to something that might help? Shouldn't this whole issue be related to the ABS control unit?

Does anyone happen to know where the ABS/ESD/ASP control unit is located in a VW Passat 3BG, and where I might be able to find the target values and the meaning of the measured value blocks for VCDS (Vag-Com Diagnostic System)?

@marco
I can now confirm the issue with the light turning on while driving. I've noticed it happening within the speed range of 20 to 30 km/h, and it persists even after a reboot!

Yes, here:



Sure, here's the translation:

"For explanation:"

The image shows the passenger footwell, the wheel arch on the right side of the picture, and the center tunnel on the left.

I hope it helps!

@m3_bremse,

It would be interesting to know when the error is permanently stored in the error memory. Because after each restart, everything is fine again for at least a short time. How does your ESP behave when an error is detected and the warning light is on? Does the ESP still function normally, or is it deactivated?

@kombiblue

Thank you, that will be helpful.

@marco

Wenn das Problem auftritt ist der Fehlerspeicher leer und bleibt es auch ! Regeln tut das ESP dann nicht unbedingt, zumindest die ASR nicht. Hatte aber auch schon einen Fall, da reagierte die ASR, Die Kontrolle flackerte und blieb letzten Endes an ! was aber komisch ist, ist der Umstand, daß die ABS-Sensoren im Stand eine Geschwindigkeit von 1km/h und der Gyro eine Querbeschleunigung von -0.4 m/s*s liefert. wohlbemerkt im Stand. Fährt man dann langsam, geht die Querbeschleunigung so ziemlich gegen null. IIs that normal?
Then there's a group of readings that indicate certain operating states. The first two values seem to represent the foot brake, at least they react simultaneously. The third value corresponds to the handbrake, and the fourth to the ESP (Electronic Stability Program) switch. It's strange, though, that the ESP switch sometimes shows as 'engaged' even when nothing was activated. Otherwise, the value is at 0 and only briefly displays the corresponding status when activated for a longer period.

Okay, it's me again!

I think things are starting to become clearer now. Just now, my speedometer stopped working. And immediately, the ESP warning light stopped illuminating. It's strange, but that's how it is.
Now, the following question arises: what is the relationship between the speed signals from the distance sensor and the ABS sensors, since the distance sensor is obviously involved? However, in this state, the ASR (Anti-Slip Regulation) functions normally, as it should. The EDS (Electronic Differential Lock) also functions correctly.

Nächstes Problem: hatte vo ca. 1500km den Wegstreckensensor wechseln müssen. Selbes Problem: Tacho zeigte nicht mehr an. Und nun schon wieder? Eigentlich nicht zu glauben. oder ? Hab leider den Fehlerspeicher nicht auslesen können. Der Akku vom Notebook war leider zu unpassender Gelegenheit mal wieder leer ! Was auch komisch ist, ist der Umstand, daß der Tacho mit Zündung an im rollenden Zustand ohne laufenden Motor ordnungsgemäß anzeigt. Sobald der Motor läuft geht der Tacho dann auf null. Also entweder hat das Motor-Stg einen Hau oder der Sensor ist wieder gestorben. AlleIt's very mysterious!

Hi m3_bremse,

That all sounds quite strange. If the ESP/ASR is still regulating when the warning light is on, it's quite likely that the instrument cluster is faulty. But let's consider something else. Have you checked the control unit for moisture? It's possible that you have a small pool of water in the water reservoir due to a blocked drain, and the control unit is partially submerged.

Um...

If I'm reading the wiring diagrams correctly at http://mitglied.lycos.de/passatpage/, then G22 is the sensor, and it actually connects directly to the instrument cluster. There shouldn't be any unexpected issues related to water. I also considered water, but dismissed it because, according to the wiring diagram, the engine control unit (ECU) is not involved!