Golf 5 BGU 1.6 FSI - No throttle response

Hello everyone,
I have a Golf 5 1.6 FSI with engine code BGU, and the driver is reporting the following problems.
The starter doesn't engage, but it works normally once the hood is opened.
The error rarely occurs.

2: When starting, it suddenly hesitates and doesn't respond to the accelerator. The pedal can then be pressed as desired, but nothing happens until second gear is engaged or the clutch is briefly depressed.
"On the last two trips, the same thing happened on the highway in the 5th lane." Okay, but here, it goes back to normal again after just a few seconds.

The two errors first appeared two weeks ago, after the timing belt was replaced.

I checked the timing belt again and readjusted the tension because the indicator on the tensioner pulley showed that the tension was slightly too high.
The starter motor not engaging happened for the first time immediately after the timing belt was replaced, and at that time, there was no coolant in the reservoir. After refilling the coolant, it started working normally again.
I've heard from various sources that the coolant reservoir is prone to malfunctioning, and I replaced it today.

I replaced the brake pedal switch today because I only experience these symptoms when I lightly press the brake pedal.
I have never been able to reproduce this error myself, to be more precise.

Last weekend, I checked the throttle valve readings using VcSkope, but I couldn't find anything unusual. I immediately re-adapted it, which cleared the error in the MSTG (Main System Test Gateway) until today.
The throttle was adjusted again today.

Could the error still be related to the fault in the DF connector?

Here's an Autoscan result.
I'm not sure what else I should check regarding those two errors.
Do you have any other ideas?
Best regards.

VCDS Version: RKS 12.12.0
Data as of: 20131116.

Friday, October 17, 2014, 19:01:24:58542

Vehicle type: 1K (1K0)
Scan: 01 03 08 09 15 16 17 19 25 42 44 46 52 56 62 72

Vehicle Identification Number: WVWZZZ1KZ5B115449 Mileage: 124620 km

00-Steering angle sensor -- Status: OK 0000
01-Motor electronics -- Status: Error 0010.
03-Brake electronics -- Status: OK 0000
08-Climate/Heating Unit -- Status: OK 0000
09-Central Electrical System -- Status: Error 0010.
15-Airbag -- Status: OK 0000
16-Wheel steering electronics -- Status: OK 0000
17-Terminal block insert -- Status: OK 0000
19-Diagnosis interface -- Status: OK 0000.
Immobilizer -- Status: OK 0000
42-door electric. Driver -- Status: OK 0000
44-Steering Assist -- Status: OK 0000
46-Comfort System -- Status: OK 0000
52-door electric. Front passenger seat. -- Status: OK 0000.
56-Radio -- Status: OK 0000
62- Door, electric, left and right -- Status: OK 0000.
72-Door, electric, high, right side -- Status: OK 0000.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 01: Engine Control Module
Label file: RKS\06A-906-033-BGU.lbl
Part number: 06A 906 033 CA
Part: SIMOS71 1.6l 2VG 9862
Revision: --H04--- Serial number: VWZ7Z0E1710923
Encoding: 0000071
Operating number: WSC 79235 146 83762
VCID: 60C996A8B3A70D1EF43-8035

1 error found:
17987 - Throttle control unit (J338))
P1579 - 008 - Adaptation not started - Intermittent.
Freeze Frame:
Speed: 864 RPM.
Binary value: 00000100
Last: 13.3%
Last: 87.5%

Readiness: 0000 0000

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 03: Brake Electronics Label file: RKS\1K0-907-379-MK60-F.lbl
Part number: 1K0 907 379 K
Part: ESP FRONT MK60 0104
Encoding: 0019073
Operating number: WSC 00046 412 08192
VCID: 3A7D04C075BB37CE9A7-806F

No error codes found.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 08: Climate Control/Heating Module. Label file: RKS\1K0-907-044.lbl
Part number: 1K0 907 044 AF
Component: Climatronic PQ35 066 0505
Operating Number: WSC 00000 000 00000
VCID: 6BD3F1844A615E46511-803E

No error codes found.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 09: Central Electronics
Label file: RKS\3C0-937-049-23-M.lbl
Part number SW: 1K0 937 049 M Hardware number: 1K0 937 049 M*
Component: On-board network module H34 0803.
Revision: 00H34000 Serial Number: 00000001405932
Encoding: 008D0F0600041800001400001400000000087B075C
Operating number: WSC 65587 150 00706
VCID: 397F1BCC70BD3CD693D-806C

Subsystem 1 - Part number: 1K1 955 119 B
Label file: RKS\1KX-955-119.CLB
Part: VW350 Wiper Blade - 012 0401
Encoding: 00065493
Operating number: WSC 65587
[color=red]
1 error found: [/color]
01117 - Load signal for generator terminal DF.
008 - Implausible signal - Sporadic.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 15: Airbag
Label file: RKS\1K0-909-605.lbl
Part number SW: 1K0 909 605 C HW: 1K0 909 605 C
Part number: 07 AIRBAG VW8 013 2100.
Revision: 02013000 Serial Number: 0033HD06C7T4
Encoding: 0012343
Operating number: WSC 00046 412 08192
VCID: 2C5132988FEF997E18B-8079

Subsystem 1 - Serial number: 6332MSME0931466BB

Subsystem 2 - Serial number: 6342MSME09093B4EM

Subsystem 3 - Serial number: 6351HSME06496E107

Subsystem 4 - Serial number: 6361HSME06470D738

No error codes found.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 16: Steering wheel electronics
Label file: RKS\1K0-953-549-MY8.lbl
Part number SW: 1K0 953 549 F, HW: 1K0 953 549 F.
Component: Steering column module 021 0050.
Encoding: 0000042
Operating number: WSC 00046 412 892928
VCID: 356717FC5CA5D8B6775-8060

No error codes found.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 17: Control panel module
Label file: RKS\1K0-920-xxx-17.lbl
Part number: 1K0 920 861 A
Component: COMBINATION INSTRUMENT VDD 1014
Encoding: 0003103
Operating number: WSC 55174 427 102528
VCID: 275BCDB49609BA26F59-8072

No error codes found.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 19: Diagnostic interface
Label file: RKS\1K0-907-530-V1.clb
Part number SW: 1K0 907 530 E, HW: 1K0 907 951.
Component: Gateway H09 0110
Revision: 09 Serial Number: 27001051300F69
Encoding: 3D3F0340070002
Operating number: WSC 00046 412 335872
VCID: 295FCB8C801D8C56E3D-807C

No error codes found.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 25: Immobilizer
Label file: RKS\1K0-920-xxx-25.clb
Part number: 1K0 920 861 A
Component: IMMO VDD 1014
Operating Number: WSC 00000 000 00000
VCID: 275BCDB49609BA26F59-8072

No error codes found.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 42: Door electronics. Driver Label file: RKS\1K0-959-701-MIN1.lbl
Part number: 1K0 959 701 E
Component: Door control unit 09 0153.
Encoding: 0000052
Operating number: WSC 00046 412 106496
VCID: 306926E8A3C7FD9E243-8065

No error codes found.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 44: Steering Assist
Label file: RKS\1Kx-909-14x-44.clb
Part number: 1K1 909 144 M
Component: EPS_ZFLS, Class 069, H08, 1901.
Operating number: WSC 79235 146 66760
VCID: 356717FC5CA5D8B6775-8060

No error codes found.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 46: Comfort System
Label file: RKS\1K0-959-433-MIN.clb
Part number: 1K0 959 433 BL
Part number: 01 KSG 0301
Encoding: 80C802087F2D8505484F06F010
Operating number: WSC 00046 412 106496
VCID: 7BF3C1C43A01CEC6C11-802E

Subsystem 1 - Part number: 1K0 951 605 C.
Part: LIN BACKUP HORN H02 1301

Subsystem 2 - Component: NGS, not mounted.

Subsystem 3 - Component: IRUE, not mounted.

No error codes found.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 52: Door electric, passenger side. Label file: RKS\1K0-959-702-MIN1.lbl
Part number: 1K0 959 702 E
Component: Door control unit 09 0153.
Encoding: 0000052
Operating number: WSC 00046 412 106496
VCID: 316F23ECA8CDF4962BD-8064

No error codes found.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 56: Radio Label file: RKS\1K0-035-1xx-56.lbl
Part number: 1K0 035 186 L
Component: Radio GR0 012 0018
Revision: 0001201S Serial Number: VWZ2Z2E2363422
Encoding: 0020200
Operating number: WSC 00046 412 892928
VCID: 2F6B2594BEF9E2663D9-807A

No error codes found.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 62: Door opener, left and right. Label file: RKS\1K0-959-703-GEN1.lbl
Part number: 1K0 959 703 C
Component: Door control unit 06 0213.
Encoding: 0000016
Operating number: WSC 00046 412 106496
VCID: 306926E8A3C7FD9E243-8065

No error codes found.

"Der schnelle braune Fuchs springt über den faulen Hund."
Address 72: Door opener, right side. Label file: RKS\1K0-959-704-GEN1.lbl
Part number: 1K0 959 704 C.
Component: Door control unit 06 0213.
Encoding: 0000016
Operating number: WSC 00046 412 106496
VCID: 316F23ECA8CDF4962BD-8064

No error codes found.

End.

Hmm, it sounds like (if your information is correct) that the vehicle is losing power somewhere.

Have you checked the battery terminals, fuses, ground connections, and the front connectors on the central electrical unit?

Today was the day to pick up the vehicle, and winter tires were installed.
When the vehicle came out of the workshop, it wouldn't start. All the relays were clicking, but nothing happened.
He opened the hood, and the engine immediately started!
How can that be?

What I noticed was that the previous owner had installed a "cigarette lighter distributor" in the engine compartment for some kind of daytime running lights. The thing was directly connected to the battery and was covered in verdigris.
I've disconnected and removed everything because it wasn't being used.
So far, so good.

Otherwise, all connections, fuses, and grounding points appeared to be okay after a preliminary check.

The issue with the delays persists.
What does this have to do with the timing belt?
Best regards.

klahaui wrote:

The problem with the delays still exists. What does this have to do with the timing belt?

Generally, I suspect that during the work, some wiring harness/connector/electrical component was moved or damaged, which caused a loose connection.

The specific part or cable that might be affected would need to be identified based on the SLP (Service Level Plan) and the overall symptom picture. However, due to my lack of knowledge about electrical systems, I'm afraid I can't offer any further assistance with gasoline engines.

...Alarm system with sensor in the engine compartment ??? -> Malfunctioning -> Interrupting the electrical circuit ???

Greetings, Styrian.

I still suspect the hood latch microswitch.
During the timing belt replacement itself, there weren't actually any connectors nearby, but something might have been damaged by the engine cover.
Since the vehicle remained parked for two weeks after that, and there were visible signs of damage caused by martens, I will unfortunately have to proceed with the SLP (presumably referring to a specific process or claim).

Since the BGU (presumably a control unit) doesn't have an LMM (likely a mass airflow sensor), there might be an issue with the lambda sensor causing it to reduce the fuel injection?

Okay, so if there's a suspicion of a "Marder" (a type of animal known for damaging cars) and there are strange errors occurring, how about thoroughly visually inspecting all the wires and connectors, even without a wiring diagram?

klahaui wrote:

Since the BGU doesn't have an LMM, could there be an issue with the lambda sensor that's causing it to reduce the injection amount?

In my opinion, yes.

I've had the plan for a long time, but I've never had the chance to do anything substantial, only for periods of 30 minutes or less.
Next weekend, the vehicle should be parked on Saturday.

I briefly checked the exposed cables, but couldn't find anything, and then the owner had to leave.

There's something new, unfortunately not from me, as I won't be able to go to the workshop for a while due to a torn ligament.
The owner was now at her place of residence, in a self-employed workshop.
There, the Lima was identified as the suspected cause, and it was determined that there was insufficient voltage.
Since the error is now occurring every minute, she doesn't want to drive the 200km and doesn't want to wait.
When I measured the voltage at the Lima (alternator) and the battery, I had approximately 13.5V. I can't tell if it looks different now.
I will, however, find out whether the issue is resolved after the repair or not.
I also find the price of 340€ plus installation for the alternator to be quite excessive; I can get it much cheaper elsewhere, but that's not my problem here.

Best regards,

Resolution:
After experiencing starting problems again, this time 70km away, I suggested that she connect a jumper cable from the negative terminal to the engine and try to start it. The car was taken to a workshop in Dresden, its home city, and the measuring tape was checked. It was found that it was no longer properly attached to the transmission.
For the past 4 months, there have been no more problems.

Best regards,

Thank you for your feedback!