AGR throughput too small... Passat CBAB engine

Hello,

"On our Passat 2.0 TDI 140hp, manufactured in 2010, the exhaust gas recirculation system, including the valve, pipes, and water cooler, has now been replaced by Volkswagen for the second time! Error in the engine control unit:"

VCDS Version: DRV 12.12.3

Address 01: Engine Control Module
Label file: DRV\03L-906-022-CBA.clb
Control unit part number: 03L 906 022 QC. Hardware: 03L 907 309.
Part and/or version: R4 2.0L EDC G000SG 6208.
Encoding: 0000072
Operating number: WSC 21964 124 86395
VCID: 76E7912701F5A9AEB11-8023
Sure, here is the translation of the text from German to English:

"1 error found:"

001025 - Exhaust gas recirculation system.
P0401 - 000 - Insufficient flow - Intermittent.
Freeze Frame:
Error status: 00100000
Error priority: 2
Error frequency: 44.
Lost Counter: 255
Mileage: 106381 km
Time: 0
Date: 2060.14.16
Time: 02:13:03

Freeze Frame:
Speed: 1725 RPM.
Speed: 60.0 km/h
Voltage: 14.06 V
Last: 14.9%
Last: 100.0%
Air mass/flow rate: 290.0 mg/H
Air mass/Flow rate: 400.0 mg/H

The first time was at 18,000 km in 2011, and the second time was now at 106,000 km in 2014.
"Maybe someone knows what might be causing this, because VW just replaces parts without investigating the root cause. I don't want to spend another 1500 euros on a new system, so I'm hoping to get some help here..." VW attributes it to frequent short trips, but in reality, the car is mostly used for journeys of over 50 km per day; it's only occasionally driven for short distances.
Thank you in advance.

Were there any noticeable signs of damage, buildup, or deposits on the AGR parts during the exchange? Otherwise, there's no point in exchanging.
Can you reproduce the error after clearing the cache?
Also, after clearing the error memory, also record the target/actual measured values for air mass, EGR mass, and boost pressure for a longer period.
What is the exact engine model (MKB)?
hg
Herbert.

Apparently, everything is blocked. Unfortunately, I haven't been able to check it. The error occurs sporadically; it works fine for days, then the error reappears. Now, of course, everything is working correctly again after the replacement. The question is, how long will this last? I need to check the MKB.

03L906022 QC = CBAB

Some parts can certainly be cleaned (by yourself). The intake channels in the cylinder head should be checked; they are probably clogged.
Is the engine otherwise in good condition? The carbon buildup could also be caused by other issues, such as incorrect valve timing, low compression, or faulty fuel injectors.
hg
Herbert.

With my premium product featuring a BRE engine, the EGR module always fails after only 70,000 to 80,000 kilometers.
Mostly long-distance routes. The cause of the problem with my motor is the plastic gears that are wearing out.

Since there are different designs, disassembling the device to identify the defect would be a good approach; this would help determine whether the problem lies with the module itself or if something else is causing the issue.

-> You can find the exact same modules in regular parts stores for about half the price. Just swap them out, check for any dirt or leaks, and you're good to go.

... to buy something that is "defective in a different way."

If the pinion gear is damaged, sometimes shifting it can help.

The teeth on the camshaft of the recently replaced AGR on the 1.6 FSI were worn .

m;

In my case, this part is called a "turbocharger intercooler for exhaust gas recirculation" (with an integrated servo motor and potentiometer). Hopefully, in the event of a problem, you won't have to replace the entire thing.
By the way, what's the actual difference between a CBAx engine (in the Passat) and a CJCx engine (in the Audi)?
I'm asking because a control element test might be relevant, involving the observation of air quality readings.
hg
Herbert.

AH

Then it's not the AGR valve, which regulates the airflow into the intake manifold, but the radiator (I just thought it was a flap).

Do you have a part number?

I'll take a look at it over the weekend. In the RLF (presumably a type of engine), there is no AGR valve installed, only the flap.
hg
Herbert.

ARG

Did they save that on the CR?

The PDs have a digital bypass valve (open/close) and an adjustable valve directly in front of the intake manifold.

It appears to be set up like this on the CJCD. The AGR (Abgasrückführung) line runs from the cooler, through the cylinder head, and directly into the intake manifold, without any additional valve. According to the RLF, this should apply to CJCx, CGLC & D, CMFA & B, and CMGB.
Only the component in the AGR cooler is being activated (it appears as N18 in VCDS, which is the valve for the AGR system). The actuator diagnosis affects it, and when the connector is pulled, the corresponding error message is logged.
On this occasion, I also noticed that the lever for the coolant control valve is adjusted in such a way that, when fully engaged, the pressure sensor is noticeably raised in its rubber mount.
hg
Herbert.