VP44: Which electrical faults are detected via diagnosis

Hello.

I just had a complete A6 AKN (apparently a very serious issue): After a completely unremarkable drive, it was parked in the garage and wouldn't start again the next morning. Since then, he hasn't contacted me again.

VW wanted to replace the VP44. Subsequently, I brought him to my place and would like to examine the diagnosis and, if necessary, perform the required work myself.

VCDS connected: Normal, except for the central locking (ZV), which supposedly had an open crash signal. (vehicle is accident-free). Seems to be a consequence of a discharged battery, according to online sources.

Since there are many reports about VP44 failures, I found the following three error descriptions on the internet:
A) Mechanical failure after air intake
B) VP44 STG defective (no longer accessible via diagnostics)
C) VP44 STG defective (End stage driver FET)

Since several people have already replaced the STG (contrary to Bosch's statements) individually and at a lower cost, instead of the entire pump, I would like to find out whether the problem lies in the mechanics or the electrical system.

Therefore, my question: How does a faulty STG manifest itself in the diagnosis?

I would like to check the VP44 CAN communication with the engine-ECU: There is no corresponding error in the MSG, so I thought it should be working. Then I disconnected the VP44 connector and had the two 01318-03-00 and 01318-49-00 codes in the fault memory. Therefore, I thought the CAN communication must be okay. However, when I reconnected the VP44 and turned on the ignition, the two errors were still in the FSP and were not marked as sporadic. Why weren't they marked as sporadic? However, they could be deleted and they didn't reappear.

I have tried to start the vehicle multiple times. The engine speed, thanks to the continuous charging, was relatively high audibly. VCDS indicates 209 or 232 U/min. The vehicle shows no signs of combustion except for two instances. However, on two occasions, it feels as though one or a few cylinders have briefly ignited. From the exhaust, a large grey diesel cloud emerged. Does this really still indicate a VP44 defect?

To ensure safety, I need to re-check the return line with a vacuum pump and loosen the ESD cover bolts. However, due to a lack of time and appropriate work clothing, I was unable to come today.

Vehicle Data:
Audi A6, 220,000 km, Engine: AKN, Tiptronik, Model Year: 2001, therefore VP44 via CAN

Complete Scan:
Saturday, 03, April, 2010, 16:20:59:49705
VCDS Version: RKS 908.2
Data Status: 20100327


Vehicle Type: 4B - Audi A6 C5
Scan: 01 02 03 06 08 15 16 17 18 34 35 36 37 45 55 56 57 65 67 75
76 77

Vehicle Identification Number: WAUZZZ4BZ1N086043 Kilometer Stand: 216530km
-------------------------------------------------------------------------------
Address 01: Motor Label file: RKS\059-907-401-AKE.lbl
Part Number: 4B1 907 401 B
Part Number: 2.5l/4VTEDC G000AG D03
Encoding: 01011
Operating Number: WSC 02325

Part Number: 00010059
Part Number: 130 106CC150_1.V5A424199089
WAUZZZ4BZ1N086043 AUZ7Z0Y1591741

No errors found.
Readiness: Not Available

-------------------------------------------------------------------------------
Address 02: Transmission Label file: RKS\01V-927-156.lbl
Part Number: 4B0 927 156 DK
Part Number: AG5 01V 2.5lTDI RdW 3132
Encoding: 00003
Operating Number: WSC 00000

No errors found.

-------------------------------------------------------------------------------
Address 03: Brakes Label file: RKS\8E0-614-111-ASR.lbl
Part Number: 3B0 614 111
Part: ABS/ASR 5.3 FRONT D00
Encoding: 00011
Operating Number: WSC 02325

No errors found.

-------------------------------------------------------------------------------
Address 08: Climate/Heating Label file: RKS\4B0-820-043-MY1.lbl
Part Number: 4B0 820 043 AF
Part: A6 Climate Control System D65
Encoding: 00063
Operating Number: WSC 02325

4 errors found:
01809 - Temperature control motor, left (V158)
41-10 - Blocked or No Power - Intermittent
00727 - Potentiometer in the control motor for defrost flap (G135)
30-10 - Interruption / Short circuit on positive line - Sporadic
00792 - Air Conditioner Switch (F129)
31-10 - Interruption / Short to Ground - Sporadic
01273 - Fresh Air Blowers (V2)
17-10 - Rule Difference - Sporadic

-------------------------------------------------------------------------------
Address 15: Airbag
Label file: RKS\4B0-959-655-AI8.lbl
Part Number: 4B0 959 655 G
Part Number: Airbag Front+Side 1001
Encoding: 00106
Operating Number: WSC 02325

No errors found.

-------------------------------------------------------------------------------
Address 17: Combination Instrument Label file: RKS\4B0-920-xxx-17.lbl
Part Number: 4B0 920 900 J
Part: C5-INSTRUMENT CLUSTER VDO D12
Encoding: 00060
Operating Number: WSC 72851
WAUZZZ4BZ1N086043 AUZ7Z0Y1591741

No errors found.

-------------------------------------------------------------------------------
Address 35: Central Locking Label file: RKS\4B0-962-258.lbl
Part Number: 4B0 962 258 D
Component: Central Locking D33
Encoding: 06721
Operating Number: WSC 02325

5 errors found:
01366 - Opening via Crash Signal
35-00 - -
01561 - Back door, left side
59-10 - not unlocked - Sporadically
01559 - Driver's Door
60-00 - safed not
01560 - Passenger Door
60-00 - safed not
01561 - Back door, left side
61-10 - Not Disinfected - Sporadically

-------------------------------------------------------------------------------
Address 56: Radio Label file:
Note: Too many communication errors.


Ende --------------------------------------------------------------------

Block 018 displays the pump status:

00000000 = No errors detected
xxxxxxx1 = Normally Open Magnetic Valve, Continuously Energized
xxxxxx1x = Magnetic valve defective
xxxxx1xx = Injector pump speed sensor defective
xxxx1xxx = Nozzle adjustment malfunction
xxx1xxxx = Injection start not detected
xx1xxxxx = Disconnect signal issued
x1xxxxxx = Engine speed not detected
1xxxxxxx = CAN-Bus data line malfunction

The VP44 could certainly have more problems than the three you posted. A common mistake is, for example, the flat cable between the speed sensor and the control unit, then you get error number 3.

guste100 wrote:

VCDS diagnostics: No issues detected, except for the central locking (ZV), which supposedly had a "crash signal" open. (The vehicle is accident-free). Seems to be a consequence of a completely discharged battery, according to the internet.

This error also occurs when a component diagnosis was performed on the ZV-STG (Central Vehicle Data System) at some point. In this case, a crash opening is simulated.

guste100 wrote:

Since several people have already replaced the STG (contrary to Bosch's statements) individually and at a lower cost, instead of replacing the entire pump, I would like to find out whether the problem is mechanical or electrical.

While you can replace the STG individually, if you purchase a new one from Bosch, it will be empty. You need to measure some parameter on the pump and then program the STG accordingly. So, the pump needs to be removed and taken to someone who can program the STG.

Hi
I need to get this out again because my VP44 probably also has a defect
Car is a 1999 A4 AFB automatic
My device is experiencing an error.
xxx1xxxx = Injection start not detected
what might indicate a problem with the tachometer or the cable from the sensor to the control unit.
Can the sensor/cable be tested, or can the break in the cable be seen?
Best regards. Dirk

Quote:

xxx1xxxx = Injection start not detected

Hm, but there's actually the needle driver for that.

Best regards, Rainer

I'll throw out a possible, simple solution, which was the case for me. Specifically, the priming pump in the tank was faulty/dirty. Exactly the same symptoms. Interestingly, I also didn't have any air in the transparent hose. Which is why nobody checked it initially. Just a tip. Checking and draining initially costs nothing


Best regards, Marcus

Edit: Just realized that this has nothing to do with the current problem. Sorry...

Rainer K. wrote:

Hmm, but there's actually the needle drive for that.

Actually, the VP44 doesn't really need it. The VP44 is capable of precisely calculating the injection start time based on the closing time of the quantity solenoid valve. Therefore, you won't notice anything at all when you remove the NHG and drive. Depending on the STG generation and software version, there might be an error entry.

The VP44 also has a K-Line, and there is a (I mean it seriously! ) Russian diagnostic tool for it.

1
CAN-L
2
CAN-H
5
Shutoff signal
6
Earth
7
Power supply, term.15
8
RPM signal
9
K-Line

For this purpose, a breakout box is obviously the more appropriate solution, and the entire system should (!) function with a simple K-line interface. I'm interested in this tool.

For replacing the FET, I also have some in stock

Hello God!

Many, many thanks for the photos!!!
I really think it's great that there's something tangible to see (although the FET in the "finish" looks really bad )

But did the pump then work properly again?

Best regards from Munich!

Although the method looks very un-German, it works perfectly when grilling the FET. The problem is, as also shown in the pictures, that the wires are made of aluminum, so you can forget about soldering. You'll have to use the pads that are marked as red areas in the picture. Are you also interested in the diagnostic tool? This is not a tool in the sense that it reads out VAG error codes, but directly displays pump parameters.

I'm going to create a list of things I can retrieve and post it here.

You would just have to tap into the K-line, but if the ignition is on, the pump's control unit will run. What isn't clear is whether it's worth trying to "trigger" it and create "readings." I think, however, that it's more likely to be seen as nonsense... As long as you don't know whether it's the mechanics or the electronics that are causing the problem, it won't necessarily get better. However, as long as the pump is located inside the diesel engine, it should actually be adequately lubricated.

There is still ongoing debate about which transistor is the best. Many people recommend the IRFZ44N. Many people use the IRFZ44 instead of the IRFZ44N. Some prefer other types, such as the IRLS3034, because it is supposed to not get so hot.

Original: Probably IRLR2905PBF or FDB44N25TM is installed!

Conclusion: The key issue lies in the appropriate performance range of the transistor and the cooling of the component, that is the main problem. But the IRFZ44(N) is likely the choice for 95% of VP44 self-reparers.

The problem is that when you mount the component INSIDE the control unit, you have to cut off the cooling and mounting flange. Someone solved this by soldering wires inside and mounting a heatsink on the pump with the transistor externally, which apparently works perfectly.

A Pole demonstrates in a YouTube video how to replace the transistor, and he uses the one that is supposedly the original one in the VP44, although it may be in a different form: IRLR2905PBF

http://www.youtube.com/watch?v=UiJ-13vldWg

Oh,

I just realized that I forgot to submit feedback at the time.
@TDI-GTI-4-Motion: Thank you for clarifying the MWB. There was no error made at that time, and therefore the communication for the pump control system was given.

Therefore, there were still issues with the FET and the mechanical pump. Due to the large amount of air in the inlet, we decided to replace the entire pump. The owner sent his old pump to a specific person in Bavaria, and after several delays, it was actually returned to him after about 8 weeks (!) in a functional condition.

Since the installation, the box has been working again.

@Deus Violentia
Unfortunately, it's too late for me; I would have liked to try it. But it's great that you're making this available for future generations

As a note: In the YouTube video, in addition to the other transistor type, the SMD package form will primarily be used, which is thermally connected to the old transistor. This seems like a clear advantage compared to the image with the Yahoo address, where I would have concerns regarding the calculation of losses.

But the principle is very clearly visible in the pictures, and what each individual does with it is then up to them. I definitely give you a big thumbs up for your contribution!

I have just written a "technical article" on the subject, which you will soon find in the database.

@Guste: Thank you so much for your kind words!

@ Guste: I also addressed the topic of power loss versus IC mounting method in my article, and I hadn't seen your contribution yet. But that's exactly what probably causes the ICs to fail in some repaired pumps. But the "solution" is in my article.

"Here is my 'expert article', which you can now see. I hope this information can be helpful to some users:"

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