How to diagnostic the AdBlue system with VDCS ?

[Jey]

Hi!

I had an orange light on the dashboard.
With VDCS, the error code (too low pressure) says it's the AdBlue system (confirmed by VW).
VW was not able to check/do the diagnostic because the problem was when it was very cold (-25°c) and when I came to VW it was only -8°c so I went back home...

Now it's -30, the problem will probably come back soon.

I would like to do myself the diagnostic.

Do you know how to do it?
What to check ?

Thanks

 

[jimc91]

Only -8 ….

 

[Jey]

yes (-30 currently).

Tha AdBlue freeze at -11/-12°c so it's probably linked.

 

[mmi]

With VDCS, the error code (too low pressure) says it's the AdBlue system

What's the exact code? Please post complete engine section with fault code from VCDS Auto-Scan

What to check ?

The pressure build-up while driving? IDE10241 - Reducing agent pump module relative press.

 

[Jey]

31150 [0x0079AE] Archive (inactive)
P20E800: Reductant Pressure Too Low
Status bits: 1
Priority: 2
Frequency: 5
Unlearning index: 255
Odometer: 287799 km
Date, time: 2019.01.23 09:43:18
Engine RPM: 824 rpm
Calculated engine load value: 47.84 %
Vehicle speed: 0 km/h
Engine coolant temperature: 69 ℃
Engine oil temperature: 18 ℃
Barometric pressure: 97 kPa
Klemme 30 voltage: 14
Paramteric values: 20 96 27 44 54 00 23 3B 4E 03 A9 70 27 00 50 29 AA FF FE 19 7A 00 FF 41 D6 04
Status: Test failed since last DTC clear, Test not completed during this operation cycle

----------------------------

31157 [0x0079B5]
P20E800: Reductant Pressure Too Low
Status bits: 1
Priority: 2
Frequency: 2
Unlearning index: 255
Odometer: 287950 km
Date, time: 2019.01.24 10:28:43
Engine RPM: 827 rpm
Calculated engine load value: 33.33 %
Vehicle speed: 0 km/h
Engine coolant temperature: 78 ℃
Engine oil temperature: 8 ℃
Barometric pressure: 97 kPa
Klemme 30 voltage: 14
Paramteric values: 20 96 28 44 54 FF C4 3B 4E 02 9D 70 27 00 52 29 AA FF EC 19 7A 00 FF 41 D6 04
Status: Test failed, Pending, Confirmed, Test failed since last DTC clear, Test not completed during this operation cycle, Warning indicator requested

Strange, the date in the log is wrong, but not the mileage.

The pressure build-up while driving? IDE10241 - Reducing agent pump module relative press.

Sorry, what do you mean?

 

[mmi]

Strange, the date in the log is wrong, but not the mileage.

The "incorrect" date is diagnostic tool issue - as date coding varies on different modules.

The pressure build-up while driving? IDE10241 - Reducing agent pump module relative press.

Sorry, what do you mean?

The "IDE10241 - Reducing agent pump module relative press" was referring to measurement values in VCDS - to have a closer look to verify that there is at least some pressure build up. The pressure should rise in a few minutes to 6...7 bars.

 

[Jey]

Ok, thank you.

Do you know hot to check it?

 

[mmi]

VCDS > Engine > Advanced measurement values > Select: IDE10241 - Reducing agent pump module relative press

Then engine running monitor (or make a log) the pressure.

 

[Jey]

Thanks !

 

[Jey]

After many minutes with nothing, staying on the parking, I had to drive few Km to see the pressure coming.






Thanks !

 

[mmi]

After many minutes with nothing, staying on the parking, I had to drive few Km to see the pressure coming.

So basically working correctly - perhaps? Perhaps you could turn logging on and do a bit more driving to see if there are any noticeable drop-outs in the pressure?