BBY: Incorrect calculation of motor torque

Hello everyone,

I'll move this thread from the general discussion forum to the section dedicated to gasoline engines, as that's where it actually belongs.

The vehicle is a 9N (Polo 4), manufactured in 2002, with 120,000 km on the odometer. Engine BBY paired with a 4-speed automatic transmission.

According to the previous owner, since April (mileage: 106,000 km), the MIL (Malfunction Indicator Lamp) and the EPC (Electronic Power Control) light have been illuminating after driving for a while, but neither of these lights has affected the driving behavior. Consequently, the car was driven as is. In April, a workshop read the error codes and then replaced the intake manifold pressure sensor. It was unsuccessful, because the error reappeared.

"I first documented the initial state (see Log 1 below), then cleared the error memory and drove approximately 50 km. This resulted in Log 2 (below). The conditions under which Log 1 was recorded are unknown; I suspect that the battery may have been discharged at some point, along with other issues that do not appear in Log 2." The consistent observation is that the GSG is not satisfied with the motor torque reported by the MSG, which is also consistent with the error message in Log 2.

During the test drive, the car seemed to function normally, except for the two illuminated warning lights. However, the engine stalled several times towards the end (once when I accidentally shifted into neutral instead of driving, and a few times when I was stopping).

After a lengthy online search, I did the following yesterday:

- LuFi cleaned (but it looked quite good already).
- Air vent properly installed (was not the case).
- Throttle body assembly removed and cleaned (it was extremely dirty from below).
- everything put back together.
- all errors resolved.
- DK re-trained.

Due to the lack of new seals from the DKE, I reinstalled the old seal after cleaning it (only from the top, as it could not be removed without damage).

Result: The engine ran very erratically for a short time, which then stabilized (this is normal after the initial start). The car then drove normally, but after a few meters, the EPC warning light came on. A little further on, the accelerator pedal stopped working, and the engine ran at approximately 1200 RPM - I suspect it went into limp mode. After a difficult and very slow journey (in automatic mode!), I finally arrived home, and the following error message was displayed in the MSG's memory:

Code:

2 Fehlercodes gefunden: 17961 - Signal Höhengeber/Saugrohrdruck             P1553 - 35-00 - unplausibles Verhältnis 17912 - Luftansaugsystem             P1504 - 35-10 - Leck erkannt - Sporadisch

It was too dark to check if I had assembled everything correctly, but basically, there's not much you can do wrong there. The air filter housing is properly seated on the DKE (engine control unit), and the two hoses connecting to the vacuum system and the KGE (cooling system component) are securely attached. The connector for the DKE is also plugged in (but since the initial setup was error-free, there shouldn't be any issues there). I can only imagine that the gasket that wasn't replaced might be the problem, but it was still clean, and I tightened the DKE sufficiently.

The GSG contained the same two codes as in Log 2.

Can anyone make sense of this? Specifically, the question is about the change after cleaning. Below the DK (presumably a marking or abbreviation), there was a crust about 1 mm thick, which I carefully removed with a wooden tool and then cleaned further with a substitute for turpentine (I didn't have any mineral spirits). It wasn't very effective, but not much dirt remains. In any case, the split that is likely responsible for the emergency mode is now open again on the DK (main board) - it was previously completely covered by the "Russ" component.

If the issue with the vacuum leak is correct, where are some other typical places to check? The BKV (presumably a system or component) seems to be working fine, so a large leak in that area is unlikely.

If I understand correctly, all the sensory components are located BEHIND the DK. Therefore, a leak is more likely to be located elsewhere, and not in front of her – and I only worked on the area in front of her.

The AGR (Automatic Gearbox) area under the DK (likely referring to a specific component or area) looks very dirty, but I haven't done anything about it yet. I don't think it's causing the problem, especially since cleaning the DK definitely made a difference.

Yesterday evening, I also didn't read out the sensor values from the intake manifold sensor and the altitude meter, but I suspect they are generally okay because the error message wasn't there before, and I haven't made any changes to them (if the cable were disconnected, there would have been a different error message).

In various forums, you can also find suggestions to check the timing. The water pump was replaced at 96,000 km (so 10,000 km before the error appeared and 24,000 km before now). Is it possible to check this easily with simple tools? I definitely wanted to check the ZR (tensioner) housing, as there are many reports of broken tensioner pulleys - but in my opinion, that doesn't quite fit with the change in the error pattern described above.

Best regards and thank you very much.

Jan.

P.S.: Update: This

Code:

Montag,15,September,2014,20:12:41:56647 VCDS -- Windows-basierter VAG/VAS-Emulator VCDS Version: 12.12.0.0 Datenstand: 20131116 Fahrzeug-Ident.-Nr.: WVWZZZ9NZ2Yxxxxxx Kilometerstand: 119970km   Reparaturauftrag: -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- Fahrzeugtyp: 9N (9N - VW Polo (2002 > 2010)) Scan: 01 02 03 08 09 15 17 19 25 37 44 45 46 56 76 Fahrzeug-Ident.-Nr.: WVWZZZ9NZ2Yxxxxxx   Kilometerstand: 119970km ------------------------------------------------------------------------------- Adresse 01: Motorelektronik        Labeldatei: RKS\036-906-034-APE.lbl    Teilenummer: 036 906 034 DE    Bauteil:  MARELLI 4MV       4442     Codierung: 00073    Betriebsnr.: WSC 00788     VCID: 58B9D3D7B8CE2CDE8C3-4B4A    WVWZZZ9NZ2Y0xxxxx     VWZ7Z0B4841395 3 Fehlercodes gefunden: 17550 - Lasterfassung             P1142 - 35-10 - Grenze unterschritten - Sporadisch 17978 - Motorsteuergerät gesperrt             P1570 - 35-10 -  - Sporadisch 17564 - Geber für Saugrohrdruck (G71)             P1156 - 35-10 - Unterbrechung/Kurzschluss nach Masse - Sporadisch Readiness: 0000 0000 ------------------------------------------------------------------------------- Adresse 02: Getriebe        Labeldatei: RKS\001-927-731.lbl    Teilenummer: 001 927 731 J    Bauteil: AG4 Getriebe 001    2990     VCID: 183993D7784EECDE4C3-5178 3 Fehlercodes gefunden: 01166 - Signal für Motormoment             03-10 - kein Signal - Sporadisch 01314 - Motorsteuergerät             49-10 - keine Kommunikation - Sporadisch 01166 - Signal für Motormoment             16-10 - Signal außerhalb der Toleranz - Sporadisch ------------------------------------------------------------------------------- Adresse 03: Bremsenelektronik        Labeldatei: RKS\6Q0-907-37x-ABS2.lbl    Teilenummer: 6Q0 907 379 E    Bauteil: ABS FRONT MK60      0103     Codierung: 0001097    Betriebsnr.: WSC 00788 785 00200    VCID: 3F8B184B6DA0FBE6AD9-513C Kein(e) Fehlercode(s) gefunden. ------------------------------------------------------------------------------- Adresse 08: Klima-/Heizungsel.        Labeldatei: RKS\6Q0-820-045.lbl    Teilenummer: 6Q0 820 045    Bauteil: Klimaanlage        X0840     VCID: EADD191F96A22E4EAA7-515A 6 Fehlercodes gefunden: 00818 - Geber für Ausströmtemperatur Verdampfer (G263)             30-00 - Unterbrechung / Kurzschluß nach Plus 01596 - Stellmotor für Frisch-/Umluftklappe (V154)             30-10 - Unterbrechung / Kurzschluß nach Plus - Sporadisch 01271 - Stellmotor für Temperaturklappe (V68)             41-10 - Blockiert oder Spannungslos - Sporadisch 01596 - Stellmotor für Frisch-/Umluftklappe (V154)             41-10 - Blockiert oder Spannungslos - Sporadisch 01596 - Stellmotor für Frisch-/Umluftklappe (V154)             29-10 - Kurzschluss nach Masse - Sporadisch 01596 - Stellmotor für Frisch-/Umluftklappe (V154)             28-10 - Kurzschluss nach Plus - Sporadisch ------------------------------------------------------------------------------- Adresse 09: Zentralelektrik        Labeldatei: RKS\6Qx-937-049-B.lbl    Teilenummer: 6Q0 937 049 B    Bauteil: BORDNETZ-SG.        1S31     Codierung: 26046    Betriebsnr.: WSC 00788     VCID: 397F76532384D5D693D-515A 1 Fehler gefunden: 01598 - Spannung Fahrbatterie             07-10 - Signal zu klein - Sporadisch ------------------------------------------------------------------------------- Adresse 15: Airbag        Labeldatei: RKS\6Q0-909-605-VW5.lbl    Teilenummer: 6Q0 909 605 S    Bauteil: 0A AIRBAG VW5  03   0007     Codierung: 12353    Betriebsnr.: WSC 00788     VCID: 479B00AB6570B326159-515A Kein(e) Fehlercode(s) gefunden. ------------------------------------------------------------------------------- Adresse 17: Schalttafeleinsatz        Labeldatei: RKS\6Q0-920-xxx-17.lbl    Teilenummer: 6Q0 920 800 A    Bauteil: KOMBI+WEGFAHRSP VDO V11     Codierung: 01143    Betriebsnr.: WSC 00000     VCID: 2B535C1BD9D87746111-515A    WVWZZZ9NZ2Y0xxxxx     VWZ7Z0B4841395 2 Fehlercodes gefunden: 01176 - Schlüssel             07-10 - Signal zu klein - Sporadisch 01314 - Motorsteuergerät             49-10 - keine Kommunikation - Sporadisch ------------------------------------------------------------------------------- Adresse 19: Diagnoseinterface        Labeldatei: RKS\6N0-909-901-19.lbl    Teilenummer: 6N0 909 901    Bauteil: Gateway K<->CAN    1S31     Codierung: 00015    Betriebsnr.: WSC 00788     VCID: F0E90B77B07ED49EE43-515A Kein(e) Fehlercode(s) gefunden. ------------------------------------------------------------------------------- Adresse 44: Lenkhilfe        Labeldatei: RKS\6Q0-423-156.clb    Teilenummer: 6Q0 423 156 M    Bauteil: LenkhilfeTRW        V210     Codierung: 00140    Betriebsnr.: WSC 00788     VCID: 397F76532384D5D693D-515A Kein(e) Fehlercode(s) gefunden. ------------------------------------------------------------------------------- Adresse 46: Komfortsystem        Labeldatei: RKS\6Q0-959-433.lbl    Teilenummer: 6Q0 959 433 H    Bauteil: 1G Komfortgerát     0001     Codierung: 00067    Betriebsnr.: WSC 00788     VCID: 40891BB7405E841ED43-4B18    Subsystem 1 - Teilenummer: 6Q2959802A    Bauteil: 1G Tõrsteuer.FS TFK 0003     Subsystem 2 - Teilenummer: 6Q2959801A    Bauteil: 1G Tõrsteuer.BF TFK 0003  Kein(e) Fehlercode(s) gefunden. ------------------------------------------------------------------------------- Adresse 56: Radio        Labeldatei: RKS\1J0-035-15x-56.lbl    Teilenummer: 6X0 035 152 B    Bauteil:  Radio BNO         0006     Codierung: 00001    Betriebsnr.: WSC 00788     VCID: 30694B77F0FE149E243-4B00 Kein(e) Fehlercode(s) gefunden. Ende   --------------------------------------------------------------------

is essentially the same issue with identical error messages, but in my case, the pairing process didn't help. And with VCDS, you really can't go wrong (there's even a guide for it here in the forum)...

Appendix:

Log 1 (PRIOR to any action, unknown background).

Code:

Dienstag,16,September,2014,14:23:48:56647 VCDS -- Windows-basierter VAG/VAS-Emulator VCDS Version: 12.12.0.0 Datenstand: 20131116 Fahrzeug-Ident.-Nr.: WVWZZZ9NZ2Yxxxxxx Kilometerstand: 120020km   Reparaturauftrag: -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- Fahrzeugtyp: 9N (9N - VW Polo (2002 > 2010)) Scan: 01 02 03 08 09 15 17 19 25 37 44 45 46 56 76 Fahrzeug-Ident.-Nr.: WVWZZZ9NZ2Yxxxxxx   Kilometerstand: 120020km ------------------------------------------------------------------------------- Adresse 01: Motorelektronik        Labeldatei: RKS\036-906-034-APE.lbl    Teilenummer: 036 906 034 DE    Bauteil:  MARELLI 4MV       4442     Codierung: 00073    Betriebsnr.: WSC 00788     VCID: 58B9D3D7B8CE2CDE8C3-4B4A    WVWZZZ9NZ2Y0xxxxx     VWZ7Z0B4841395 1 Fehler gefunden: 17550 - Lasterfassung             P1142 - 35-10 - Grenze unterschritten - Sporadisch Readiness: 0000 0100 ------------------------------------------------------------------------------- Adresse 02: Getriebe        Labeldatei: RKS\001-927-731.lbl    Teilenummer: 001 927 731 J    Bauteil: AG4 Getriebe 001    2990     VCID: 183993D7784EECDE4C3-5178 2 Fehlercodes gefunden: 01166 - Signal für Motormoment             03-10 - kein Signal - Sporadisch 01166 - Signal für Motormoment             16-10 - Signal außerhalb der Toleranz - Sporadisch ------------------------------------------------------------------------------- Adresse 03: Bremsenelektronik        Labeldatei: RKS\6Q0-907-37x-ABS2.lbl    Teilenummer: 6Q0 907 379 E    Bauteil: ABS FRONT MK60      0103     Codierung: 0001097    Betriebsnr.: WSC 00788 785 00200    VCID: 3F8B184B6DA0FBE6AD9-515A 1 Fehler gefunden: 01314 - Motorsteuergerät             013 - bitte Fehlerspeicher auslesen - Sporadisch ------------------------------------------------------------------------------- Adresse 08: Klima-/Heizungsel.        Labeldatei: RKS\6Q0-820-045.lbl    Teilenummer: 6Q0 820 045    Bauteil: Klimaanlage        X0840     VCID: EADD191F96A22E4EAA7-515A 3 Fehlercodes gefunden: 00818 - Geber für Ausströmtemperatur Verdampfer (G263)             30-00 - Unterbrechung / Kurzschluß nach Plus 01596 - Stellmotor für Frisch-/Umluftklappe (V154)             30-10 - Unterbrechung / Kurzschluß nach Plus - Sporadisch 01596 - Stellmotor für Frisch-/Umluftklappe (V154)             29-10 - Kurzschluss nach Masse - Sporadisch ------------------------------------------------------------------------------- Adresse 09: Zentralelektrik        Labeldatei: RKS\6Qx-937-049-B.lbl    Teilenummer: 6Q0 937 049 B    Bauteil: BORDNETZ-SG.        1S31     Codierung: 26046    Betriebsnr.: WSC 00788     VCID: 397F76532384D5D693D-5178 Kein(e) Fehlercode(s) gefunden. ------------------------------------------------------------------------------- Adresse 15: Airbag        Labeldatei: RKS\6Q0-909-605-VW5.lbl    Teilenummer: 6Q0 909 605 S    Bauteil: 0A AIRBAG VW5  03   0007     Codierung: 12353    Betriebsnr.: WSC 00788     VCID: 479B00AB6570B326159-515A Kein(e) Fehlercode(s) gefunden. ------------------------------------------------------------------------------- Adresse 17: Schalttafeleinsatz        Labeldatei: RKS\6Q0-920-xxx-17.lbl    Teilenummer: 6Q0 920 800 A    Bauteil: KOMBI+WEGFAHRSP VDO V11     Codierung: 01143    Betriebsnr.: WSC 00000     VCID: 2B535C1BD9D87746111-515A    WVWZZZ9NZ2Y0xxxxx     VWZ7Z0B4841395 Kein(e) Fehlercode(s) gefunden. ------------------------------------------------------------------------------- Adresse 19: Diagnoseinterface        Labeldatei: RKS\6N0-909-901-19.lbl    Teilenummer: 6N0 909 901    Bauteil: Gateway K<->CAN    1S31     Codierung: 00015    Betriebsnr.: WSC 00788     VCID: F0E90B77B07ED49EE43-515A Kein(e) Fehlercode(s) gefunden. ------------------------------------------------------------------------------- Adresse 44: Lenkhilfe        Labeldatei: RKS\6Q0-423-156.clb    Teilenummer: 6Q0 423 156 M    Bauteil: LenkhilfeTRW        V210     Codierung: 00140    Betriebsnr.: WSC 00788     VCID: 397F76532384D5D693D-515A Kein(e) Fehlercode(s) gefunden. ------------------------------------------------------------------------------- Adresse 46: Komfortsystem        Labeldatei: RKS\6Q0-959-433.lbl    Teilenummer: 6Q0 959 433 H    Bauteil: 1G Komfortgerát     0001     Codierung: 00067    Betriebsnr.: WSC 00788     VCID: 40891BB7405E841ED43-4B18    Subsystem 1 - Teilenummer: 6Q2959802A    Bauteil: 1G Tõrsteuer.FS TFK 0003     Subsystem 2 - Teilenummer: 6Q2959801A    Bauteil: 1G Tõrsteuer.BF TFK 0003  Kein(e) Fehlercode(s) gefunden. ------------------------------------------------------------------------------- Adresse 56: Radio        Labeldatei: RKS\1J0-035-15x-56.lbl    Teilenummer: 6X0 035 152 B    Bauteil:  Radio BNO         0006     Codierung: 00001    Betriebsnr.: WSC 00788     VCID: 30694B77F0FE149E243-4B18 Kein(e) Fehlercode(s) gefunden. Ende   --------------------------------------------------------------------

Log 2 (AFTER deletion and 50 km test drive)

http://www.motor-talk.de/forum/polo-1-4-16v-abgas-und-epc-leuchte-t4671659.html

Hi Jan,

The BBY is the successor to the AUA, which is a condensation-frost motor.

I don't fully understand this issue, but could there be a crack somewhere that lets in air during the winter?

m;

Hi,

Hmmm... the intake manifold is completely made of plastic, but that might have already changed at the cylinder head. However, it's argued that the issue with the foreign air only appeared after the action involving the DK device.

Does anyone know if the BBY is also affected, and if so, where exactly would it tear, and what other consequences would that have? He says coolant doesn't matter, and that smoking isn't a problem either.

My current theory (copied from an online forum):

Quote:

Yesterday evening, I came across a lengthy thread on the A2 forum that perfectly describes my problem and deals with cleaning the DK (the error symptoms before cleaning match perfectly: MIL and EPC lights on, occasional stalling at idle when warm). Many people reported that the DK reconnected without needing to be re-registered after cleaning, but for some, the lack of registration resulted in exactly the behavior I'm experiencing with the limp mode. No one posted any error logs (those with VCDS were able to re-register it immediately), but the consensus was that this happened when the DK was so dirty that the emergency gap was completely blocked. That was the case for me too. Therefore, either the calibration didn't work, or I wasn't thorough enough when cleaning, especially around the axles. Consequently, the flap might not be closing completely, so the position that the MSG believes is "closed" might actually still leave a wide gap where the dirt used to be. That would at least explain the "false air," because then more air would be entering than the MSG believes is entering. I'm currently in Berlin until tomorrow, and I'm getting a new gasket here (still another option), as well as a good cleaner (brake cleaner should work in principle, but I only had turpentine substitute in Hagen; the perfect solution would be an expensive DK cleaner from Liqui-Moly). The activated carbon filter and its solenoid valve are also potential culprits, but they can be easily checked using VCDS.

Best regards,

Jan.

here
Okay, I'm ready. Please provide the German text you want me to translate.
The problem was that the DK was hitting against the housing.

Along with the debris, it remained open by approximately 0.2 mm, resulting in an idle speed of 1200 rpm.
The makeshift solution was to let the accelerator pedal slip, causing it to hit the actual end stop.

In the long run, the solution involved cleaning and possibly removing the valve from the shaft, and then reinstalling it.

But the BBY DK will be clinched, right?

EDIT: Oh, no. eBay says it's screwed on. So, I'll need to unscrew it and polish the edge. That helped a lot with the bus.

m;

Hi,

I haven't seen any screws, at least, but they could be hidden under the dirt. Cleaning it mechanically is not a problem, even without disassembling it; the issue was more about finding the right cleaning chemicals.

Quote:

The makeshift solution was to let the accelerator pedal slip, causing it to hit the actual end stop.

"This won't achieve anything with an electronic throttle without a throttle cable. I'll test tomorrow to see how easily they can be pressed against the spring until they hit the stop, and how much debris is still in the way." He will be cleaned up, and then we'll see.

I believe that the servo will likely not have much more force than it needs to overcome the spring. Therefore, contamination can certainly effectively limit its movement. In addition, I wanted to see how far the system goes during the actuator diagnosis process – this can be observed very well with the BBY.

Best regards,

Jan.

Sure.

"Letting off the gas pedal" is not.
It should have shown how "delicate" the coating was, but still, he wanted it to be scrubbed off by "hand."

m;

Hi,

Okay, so... the DK has been cleaned again, and I've made sure that it can now reach both limit switches with comparable force. This was also evident during the calibration process – last time it only reached 5%, but now it's reaching 0.2% or so. In the actuator diagnostics, the DK can now completely oscillate between both limit switches. There was a new gasket installed under the throttle body unit, as the old one was very dirty.

The valves for the activated carbon filter and EGR system are functioning during the actuator test, but I didn't investigate further because I wanted to start test driving first.

The result of my short ride (only uphill at the beginning, so I can get home safely if needed) is that neither the MIL (Malfunction Indicator Lamp) nor the EPC (Electronic Power Control) warning light has reappeared. I haven't read any error codes yet, but since one of the displays has always appeared so far, things look good for now.

Therefore, the theory that the partially cleaned DK valve may have allowed air to pass through while in the resting position, but could not be completely closed, is quite plausible. From the perspective of the MSG (presumably a monitoring system), this would be interpreted as either a false air intake or a leak in the intake system.

I'll observe and report back later.

Best regards,

Jan.

... "not just clean, but pure"

Then she almost could have participated in the "throttle valve ballet" at the Automechanika trade fair.

http://www.actronics.eu/wp-content/uploads/2013/07/hp_fairs.jpg

m;

It's not that clean, you know. I naturally focused on the relevant areas (i.e., those that could potentially obstruct the valve's movement) and cleaned the rest, but didn't remove every tiny trace of residue.

By the way, the buildup was similar to what I had to scrape out of the AGR valve on my Ibiza TDI after 40,000 km, only it was on the underside of the throttle valve in this case. The AGR (presumably a specific component) connects directly below, and that's why it looks like that.

If it doesn't rain as much tomorrow, I'll take a slightly longer test ride (because I don't want to get too wet if I have to walk back...).

Best regards,

Jan.

I even polished the "relevant" areas with stainless steel cleaner at the end.

The Rot/Weiss grinding and polishing compound was very helpful when removing the last layers of coating.

m;

Hi,

Okay, so... today I took the car for a test drive of about 15 km. Before the repair, the EPC and MIL lights came on after about 1 km. After the first, unsuccessful cleaning attempt, the EPC light came on after 20 meters, and the car went into limp mode after 500 meters. This time, nothing like that happened; the car simply drove normally, without any lights flashing.

After the drive, there were no error codes in either the MSG (Main System Gateway) or the GSG (Gearbox Control Unit), except for an error code related to the braking system.

Code:

01314 - Motorsteuerger�t             013 - bitte Fehlerspeicher auslesen - Sporadisch

"However, the cause is clear, because after the emergency stop problem, I only cleared the error memory of the MSG and GSG." So, that's what's left.

It looks good.

The idle speed is warm and stable at 680 RPM, as indicated in the data for the engine when paired with an automatic transmission. The engine load at idle is approximately 15%, which is also very close to the allowed range. "Zuviel" here likely indicates a problem with the valve timing or ignition, but it doesn't seem to be the case.

Best regards,

Jan.