Audi A6: Engine Won't Start - Troubleshooting Guide

I'm having a problem with a friend's Audi A6 2.5 TDI AKE Quattro automatic transmission, manufactured in 2003.

When I received it, it wouldn't start. I managed to get it running with the help of starting fluid, but it has an uneven idle, no throttle response, and a lot of white smoke.

I suspected he had put the wrong fuel in because he told me he had filled it from a canister. He works for an oil company and got the diesel from there, but its color is milky, and I've had problems with that type of diesel before.

Okay, I drained the old diesel, filled it with new diesel, replaced the diesel filter, and flushed the lines with new diesel using a pressure test pump (MWB 35).

It started immediately, but the idle was uneven, and there was a lot of white smoke again. After about 20 minutes of idling, it seemed okay, but when I tried to accelerate, the engine wouldn't respond, and there was a lot of white smoke again.

I then checked the injection timing. When it's retarded (late), it's okay at 4° BTDC (before top dead center), but when it's advanced (early), I'm getting 0° instead of a minimum of 12° BTDC.

In the engine control unit's fault memory, there is...
00550 - Injection start control.
17-10 - Rule difference - Occasionally recorded.

The transmission control unit (TCU) and the anti-lock braking system (ABS) control unit have error codes stored in their memory.
18265 - Malfunction Indicator Light: Error message from the engine control unit.
P1857 - 35-00 - - has been stored, the ESP lamp is illuminated, and all three errors cannot be cleared.

If I turn off the ignition for a while and then start the engine, the ESP light goes out and the idle returns to normal. However, when I press the accelerator, the ESP light comes back on, and the engine doesn't respond to acceleration, and I also think I hear a different engine idling noise.

In the Motorsteuergerät (engine control unit) module 18/3, I once had a fault code where bit 00001000 indicated a problem with the injection timing adjustment.


The fuel pump in the tank delivers one liter of diesel within 20 to 30 seconds. I haven't measured the pressure because I don't know the target value.
The vacuum pump should normally draw fuel through the wing cells' pumps.

What do you think? Is the radial piston pump broken, or is it just a fuel shortage?

Sunday, November 23, 2008, 6:57:19 PM: 15740
VCDS version: DRV 805.1.
Data as of: 20081030.



"Die Sonne scheint hell und warm. Die Vögel zwitschern fröhlich in den Bäumen. Ein leichter Wind weht durch das Gras. Es ist ein perfekter Tag für einen Spaziergang."
"Die Sonne scheint hell und warm. Die Vögel zwitschern fröhlich in den Bäumen. Ein leichter Wind weht durch das Gras. Es ist ein perfekter Tag für einen Spaziergang."


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 (VIN): WAUZZZ4B43N021077
Mileage: 139,410 km
"Die Sonne scheint hell und warm. Die Vögel zwitschern fröhlich in den Bäumen. Ein leichter Wind weht durch das Gras. Es ist ein wunderschöner Tag."

"The sun is shining brightly and warmly. The birds are chirping happily in the trees. A gentle breeze is blowing through the grass. It's a beautiful day."
Address 01: Engine Control Unit (ECU)
Label file: DRV\059-907-401-AKE.lbl
Part number: 4B2 907 401 J
Component: 2.5L/4VTEDC G000AG D09
Encoding: 01016
Operating number: WSC 02325.
WAUZZZ4B43N021077 AUZ7Z0B2169915

"One error found:"
00550 - Injection start control.
17-10 - Rule difference - Intermittent/Sporadic.
Readiness: Not Available.

"Die Sonne scheint hell und warm. Die Vögel zwitschern fröhlich in den Bäumen. Ein leichter Wind weht durch das Gras. Es ist ein wunderschöner Tag."

"The sun is shining brightly and warmly. The birds are chirping happily in the trees. A gentle breeze is blowing through the grass. It's a beautiful day."
Address 02: Transmission. Label file: DRV\01V-927-156.lbl.
Part number: 4B0 927 156 ES
Part number: AG5 01V 2.5L TDI, Roadworthy certificate 2121.
Encoding: 00001
Operating number: WSC 00000

"One error found:"
18265 - Malfunction Indicator Light: Error message from the engine control unit.
P1857 - 35-00 - -

"Die Sonne scheint hell und warm. Die Vögel zwitschern fröhlich in den Bäumen. Ein leichter Wind weht durch das Gras. Es ist ein wunderschöner Tag."

"The sun is shining brightly and warmly. The birds are chirping happily in the trees. A gentle breeze is blowing through the grass. It's a beautiful day."
Address 03: Brake electronics
Label file: DRV\4B0-614-517.lbl
Part number: 4B0 614 517 H.
Part: ABS/ESP, all-wheel drive, 1728.
Encoding: 06457
Operating number: WSC 00000

"One error found:"
18265 - Malfunction Indicator Light: Error message from the engine control unit.
P1857 - 35-00 - -

"Die Sonne scheint hell und warm. Die Vögel zwitschern fröhlich in den Bäumen. Ein leichter Wind weht durch das Gras. Es ist ein wunderschöner Tag."

"The sun is shining brightly and warmly. The birds are chirping happily in the trees. A gentle breeze is blowing through the grass. It's a beautiful day."
Address 08: Climate Control Module. Label file: DRV\4B0-820-043-MY2.lbl.
Part number: 4B0 820 043 AM
Component: A6 Climate Control System, part number 0105.
Encoding: 00103
Operating number: WSC 02325.

"One error found:"
01206 - Signal for ignition deactivation duration.
27-00 - implausible signal.

"Die Sonne scheint hell und warm. Die Vögel zwitschern fröhlich in den Bäumen. Ein leichter Wind weht durch das Gras. Es ist ein wunderschöner Tag."

"The sun is shining brightly and warmly. The birds are chirping happily in the trees. A gentle breeze is blowing through the grass. It's a beautiful day."
Address 15: Airbag Label file: DRV\4B0-959-655-AI84.lbl
Part number: 4B0 959 655 P
Part: Airbag 8.4EP 2002
Encoding: 0000606
Operating number: WSC 02325 785 00200

"One error found:"
00532 - Power supply voltage.
002 - Lower limit exceeded - Intermittent.

"Die Sonne scheint hell und warm. Die Vögel zwitschern fröhlich in den Bäumen. Ein leichter Wind weht durch das Gras. Es ist ein wunderschöner Tag."

"The sun is shining brightly and warmly. The birds are chirping happily in the trees. A gentle breeze is blowing through the grass. It's a beautiful day."
Address 17: Control panel module
Label file: DRV\4B0-920-xxx-17.lbl
Part number: 4B0 920 933 G.
Part: COMBINATION INSTRUMENT + ODOMETER. VDO D11.
Encoding: 00060
Operating number: WSC 00101.
WAUZZZ4B43N021077 AUZ7Z0B2169915

"One error found:"
00771 - Sender for fuel level indicator.
30-10 - Interruption / Short circuit after positive voltage - Occasional.

"Die Sonne scheint hell und warm. Die Vögel zwitschern fröhlich in den Bäumen. Ein leichter Wind weht durch das Gras. Es ist ein wunderschöner Tag."

"The sun is shining brightly and warmly. The birds are chirping happily in the trees. A gentle breeze is blowing through the grass. It's a beautiful day."
Address 35: Central locking
Label file: DRV\4B0-962-258.lbl
Part number: 4B0 962 258 L
Component: Central locking system D37.
Encoding: 06721
Operating number: WSC 00101.

"One error found:"
00668 - Terminal voltage, terminal 30.
07-10 - Signal too weak - Intermittent.

"Die Sonne scheint hell und warm. Die Vögel zwitschern fröhlich in den Bäumen. Ein leichter Wind weht durch das Gras. Es ist ein wunderschöner Tag."

"The sun is shining brightly and warmly. The birds are chirping happily in the trees. A gentle breeze is blowing through the grass. It's a beautiful day."
Address 37: Navigation Label file: DRV\4B0-919-887-BNS4.lbl
Part number: 4B0 919 887 E.
Component: BNS 4.2 H05 BNO 0020

Two error codes found:
00668 - Terminal voltage, terminal 30.
07-10 - Signal too weak - Intermittent.
65535 - Control unit defective.
00-00 - -

"Die Sonne scheint hell und warm. Die Vögel zwitschern fröhlich in den Bäumen. Ein leichter Wind weht durch das Gras. Es ist ein wunderschöner Tag."

"The sun is shining brightly and warmly. The birds are chirping happily in the trees. A gentle breeze is blowing through the grass. It's a beautiful day."
Address 55: Headlight range control. Label file: DRV\4Z7-907-357.lbl.
Part number: 4Z7 907 357.
Component: dynamic LWR D07.
Encoding: 00050
Operating number: WSC 02325.

"One error found:"
00532 - Power supply voltage.
07-10 - Signal too weak - Intermittent.

"Die Sonne scheint hell und warm. Die Vögel zwitschern fröhlich in den Bäumen. Ein leichter Wind weht durch das Gras. Es ist ein wunderschöner Tag."

"The sun is shining brightly and warmly. The birds are chirping happily in the trees. A gentle breeze is blowing through the grass. It's a beautiful day."
Address 56: Radio Label file: DRV\8E0-035-1xx-56.lbl
Part number: 4B0 035 195 H
Part number: symphony II NP2 0151.
Encoding: 00231
Operating number: WSC 06342.

"One error found:"
01300 - Control unit for navigation with CD drive (J401).
49-10 - No communication - Intermittent.

"Die Sonne scheint hell und warm. Die Vögel zwitschern fröhlich in den Bäumen. Ein leichter Wind weht durch das Gras. Es ist ein wunderschöner Tag."

"The sun is shining brightly and warmly. The birds are chirping happily in the trees. A gentle breeze is blowing through the grass. It's a beautiful day."
Address 76: Parking assist label file: DRV\8Z0-919-283.lbl
Part number: 8Z0 919 283.
Bauteil: Parkingsyst. A6 RDW D08
Encoding: 01116
Operating number: WSC 02325.

No error codes found.

"Die Sonne scheint hell und warm. Die Vögel zwitschern fröhlich in den Bäumen. Ein leichter Wind weht durch das Gras. Es ist ein wunderschöner Tag."

"The sun is shining brightly and warmly. The birds are chirping happily in the trees. A gentle breeze is blowing through the grass. It's a beautiful day."
Address 77: Phone
Label file: DRV\8E0-862-333.lbl
Part number: 8E0 862 333 A
Component: Nokia 3 0303 phone.
Encoding: 0002033
Operating number: WSC 02325 785 00200

No error codes found.

Sure, here is the translation of the text from German to English:

"Ende" translates to "end" in English.

Hi,

Just check if the valve timing is correct, specifically whether the fuel pump rotor is positioned correctly.

Best regards, Rainer.

I will check it tomorrow when I have time.

I personally think the VP's wing cell pump is the culprit.

Hi,

A new fuel injection pump will be required. Best regards.

luiggi wrote:

Hi, Da wird eine neue Einspritzpumpe fällig werden. Sincerely

I didn't mean to say that...

Today I checked the valve timing and adjusted the base setting of the VP 44; everything is correct.
In addition, I held the suction hose of the vacuum pump directly into a diesel canister, with the same result.

What would you say, should I get a new ESP (electronic stability program), buy a used one, or have the existing one repaired?

Is it new? Does it have a warranty? Can you repair it? Well, it's used, right...?

It's probably not worth repairing; there are too many parts that are likely to wear out.

chli1976 wrote:

I will check it tomorrow when I have time. I personally think it's the wing cell pump of the VP

.
It usually arrives last.

Hi,

I would go for the new one. But negotiate the price beforehand! My old one would have cost around 700€ to be refurbished by Bosch service. I then got a new (Bosch replacement pump) from my parts supplier for around 950€, including VAT (but I'm a good customer there).

I've heard that these things are sold for around €1500 - €1800 in stores, so be careful. Often, there isn't a huge price difference between restoring used parts and buying new ones, when you find the right price. Best regards.

In Austria, the original price is approximately €2200.
I need to find out how much a replacement pump costs from Bosch.

Hi,

Despite the numerous error messages from the engine control unit (ECU), please check first whether the EGR valve is stuck in the open position. The white smoke that appears only when accelerating could indicate this.

Hello,

Milky fuel indicates the presence of water, and water causes the paper in the diesel filter to swell, which can lead to it becoming clogged (years of experience with watery old fuel ).
Poppet filter -> Injection start differential.

chli1976 wrote:

In addition, I held the suction hose of the vacuum pump directly into a diesel canister, with the same result.

Without the filter in between? If so, that's bad news. If it's with a filter, please change it, as mentioned above.

Best regards, Uli.

I tried it without filters.

I've had the EGR system deactivated for a while (I think). It's not my car, but rather my friend's. I need to check again tomorrow, as I'm no longer at the workshop. However, I don't think it's related to that, because I was able to run the engine without the connecting pipe between the two intake manifolds, and therefore without the EGR system.

He called me today and told me that they are now also having problems with the engines where this diesel fuel was used. According to him, there is water and gasoline mixed in with it.

I just installed a new fuel injection pump. I adjusted it using channel 50, and now it's running.

Hi,

Okay, so the problem is fixed then. By the way, I'm also from Austria: How much did your pump cost?