S6 C6 2006 5,2 v10 - Air flow/Fuel pressure errors

A6 All/ S6 All
#1

Hey everyone,

The last time I drove the car, it ran perfectly. But after sitting idle for a week, it could hardly start and gave all these errors. (Carista app)

Basic OBD
Basic OBD1170×2532 184 KB
Engine (2)
Engine (2)1170×2532 171 KB
Engine
Engine1170×2532 172 KB
Transmission - ABS
Transmission - ABS1170×2532 164 KB

It is clear that the mixture between air and petrol is not correct. It has very low rpm and does not accept acceleration at all.
So I thought it would be the MAF sensors that needed cleaning. I therefore removed both air filters and cleaned the MAF sensors with “contact cleaner”, but it did not help.

When I try to reset the errors they come back immediately.

No air hoses have jumped off. (As I see)

ESP and ECP also light up.

Is it possible to see which maf sensor is reporting an error? and why does it also report errors on ESP due to ECP?

Is there an error that triggers something else?

Please help if you have any ideas :slight_smile:

#2

So the car is running? If yes you would need to log what MAFs are showing and log the fuel pressure. Remember car has 2 ECUs, so you need to check for MAF readings in both of them. Unfortunately I will not be able to help in terms of how to do it with the program you have. In VCDS you would need to log group 003 in both ECUs, and group 140 in one of them (it does not matter as there is only one fuel pressure sensor)

#3

Yes, the car is running, but very bad!
(Sometimes it stops right away when I touch the accelerator.)
I was drive to work and back again, 2x18 km. But that was pure luck I made it! With a lot of stops during the way…

I dont have VCDS.

Could i unplug one of the MAFs to see if the error code will be shown?

Is there any other way to try something out, to see if the senor is bad?

Will the car drive that bat, if only ONE MAF is broken? What are the odds, that both sensors are broken same time, since last trip?

Seriusly, the car was driving perfect last time, with NO errors.!

#4

Try unplugging both of the MAF sensors and see if it makes any difference.

#5

I would try that!
If the same errors shows, will that indicate the MAF sensors is broken? Or will the errors not be shown if the MAFS are broken?

And how will I figure out, if it is only one or both sensors that are broken?

#6

Another question @Dlugi11

I see that on the left MAF sensor, there are only 4 wires. (The fifth plug is covered?)

And the right MAF have 5 wires.

Is it possible to switch them? Or is there a ‘Left and Right’ one?

Because, when I searh for the OEM number ‘07C906461A’ I can’t find a ‘Left and Right’ one?

#7

I belive they are the same part. When you unplug them there will be errors, but if it is mafs that are the issue the engine should run better, becouse engine will then use calculated air flow mass based on rpm, temperature and height above sea

#8

@Dlugi11
I have just unplugged both MAF sensors, and filters… And it is exactly the same symptoms!

It starts for a few seconds, with very low rpm, and then stops…

So, do you think it is another problem, than the MAF sensors?
I think it sounds odd, that it makes no differents at all, to remove both filter/sensors?

I have read something about a fuse for the sensor, but I can’t figure out where it is?!

image|666x500

#9

My guess would be you either have a fuel pressure issue, throttle body issue or some other electrical gremlin. It would be great if you could provide your fuel rail pressure on running engine, and also check if the throttle bodies work correctly. If both would check out to be fine than I would search for some electrical issue.
PS. Check for water under ECUs, maybe you have clogged water drains

What is this fuse for?
#10

@Kimovitzh @justincredible
Hello guys, you have helped me before, do you have any andeas?:blush:

And thank you for you help so far @Dlugi11

#11

The ECU is totally dry😊

image
image1512×2016 1.34 MB

I am not sure how to check the orher things you say.?

Can I do anything by myself?

#12

I try to check the fuse, and actially one was blown… I changed it, but same symptoms… But the fuse was blown again… Only few seconds after…

So why did that happen?

image
image3024×4032 2.77 MB

#13

You probably have a short somewhere. Maybe when the car was sitting you had an unwanted guest under the hood?

#14

The car was actually standing still one week. And the battery is 1,5 years old.
Could it be bad/low battery?

In the beginning the mmi said 100%, but I dont know if that i true?

Now it says 10% because of all the ‘turns’…

Maybe I should try to charge the battery, to full?

Do you think that could help?

#15

Doesn’t hurt to try, you have to charge it anyway. However I doubt it’s a culprit, because unless you had very low temperatures during that week, the battery would not drain in a week

#16

Morning Blackwidow,

Batt needs to be over 70% charge at all times. Deff charge or replace with new and code appropriately. That is not issue popping fuse though. I had similar issue with bank 2 fuel pump Regulator shorted out popping same fuse once b4. On a separate issue, in trunk rt side fuse panel one day I decided to install a fuse in a open spot because why the hell not I thought. After I installed said fuse in trunk panel she kept blowing 15a under hood. I removed fuse in trunk that I randomly installed and all issues have since cleared over 2yr now…

Hope it helps steer u in proper direction, GoodLuck

#17

Also, I would unplug both HP fuel pump reg’s, then replace 15a fuse in LH plenum fuse box and turn car on and plug in HP pump reg’s 1 at a time while watching 15a fuse, essentially checking for shorts in said circuits…

#18

Hello guys,

I just have an update!

I was looking at the battery, saw that the ground was tight as it should be. (That would have been nice if that was the problem…)

So I put all together, MAF, air filters etc.
And changed the fuse again.

And guess what. It started, with NO errors!

I drive about 1 km. home, so I could charge the battery. On my way home it was drivng fine. Normal rpm. But it has still a bit struggle to handle too much trottle.

Back home I stop and started a few times, and no errors…

But… After a few times, same errors, and the fuse was blown again…

So… Something kill that fuse!
But that means that both MAFs are fine, and the fuel pumps also…

But something burn the fuse?

@seaton83 I am not sure exactly what you did with the fuse in the trunk?

When you say that I should unplug the fuel pumps, do you mean this connector? (See photo).

image
image1170×1510 1.16 MB

Just a question: if I unplug both fuel pumps, would it even start then?

#19

Once happened to me while driving, clip on that plug cracked and unplugged, EPC light come in and car didnt pull, managed to get home and park car, switch
off car, try to start and it and after some time it start like 3 cylinder diesel tractor working on 2 cylinder and shut off by itself, reconected plug, reset error and no issues

1 Like
#20

yes thats the