1.6 TDI AGR module cannot be programmed

Hello,

I replaced the AGR module in a Skoda Fabia 2 with a 1.6 TDI engine. After installation, the error memory was cleared, and a test drive was performed. After a short time, the vehicle went into limp mode, and the error code "Potentiometer for exhaust gas recirculation signal too low" was read. I then tried to calibrate the AGR system using the basic settings in the engine control unit. This didn't really work, as the error is constant. If I clear the error memory while the engine is running and then try to select the basic settings, the engine speed increases slightly, but there is no response. I'm not sure how long the calibration process takes, but it doesn't seem normal to me.

I will perform another car scan tomorrow and also check the connection to the control unit. However, it is probably quite unlikely that a broken wire or something similar will occur during the test drive.

A MagnetiMarelli EGR module was installed, and I'm assuming it's not already broken, but I don't know how to determine that without disassembling it.

Maybe someone has some advice.

Regards,

Lukas.

Hi,

Please post the Autoscan data and search for the signal corresponding to the potentiometer in the engine control unit's measured values.
You might have a cable or connector problem.

Best regards, Rainer.

Hello,

Here's the car scan data. Some values are already included. Unfortunately, I haven't yet obtained a repair manual or wiring diagram, so I'll report further progress tomorrow.


Address 01: Engine Control Module
Label file: DRV\03L-906-023-CAY.clb
Control unit part number: 03L 906 023 NG
Hardware: 03L 906 023 LK
Component and/or version: R4 1.6l TDI H33 9978.
Encoding: 00114016002400080000
Operating number: WSC 13765 031 00015
ASAM Dataset: EV_ECM16TDI02103L906023NG 003011 (SK25)
ROD: EV_ECM16TDI02103L906023LL.rod
VCID: 78F82575C365538FA1-802C
Sure, here is the translation of the text from German to English:

"1 error found:"

7343 - Potentiometer for exhaust gas recirculation (G212)
P0407 00 [165] - Signal too low.
Warning light ON - unconfirmed - checked since last reset.
Environmental conditions:
Error status: 00000001
Error priority: 2
Error frequency: 2
Date: 2000.00.00
Time: 00:00:00

Motor speed: 0.00 rpm.
Normalized load value: 0.0%
Vehicle speed: 0 km/h
Coolant temperature: 55 °C
Intake air temperature: 29 °C
Atmospheric pressure: 970 millibars.
Voltage at terminal 30: 12.649 V.
Lost count after OBD: 40
Exhaust gas recirculation (EGR) valve: Actual value - ANG_EGRV[0]: -12.219 %.
Exhaust gas recirculation valve: Control signal - ANG_SP_EGRV[0]: 0.000 %
High-pressure exhaust gas recirculation valve control: PWM_HBR_EGRV[0]: 0.000%
High-pressure exhaust gas recirculation valve: Actual value of raw voltage - V_EGRV[0]: 0.684 V.
Exhaust gas recirculation valve: Offset closed - V_EGRV_BOL[0]: 1.001 V
Exhaust gas recirculation valve: Offset open - V_EGRV_TOL[0]: 3.999 V.
High-pressure exhaust gas recirculation valve: Status-LF_STATE_EGRV_DISP[0]: 2


Regards,

Lukas.

Hi,

This is not an automatic scan. Just check the actual and target values of the position sensor during normal operation.
If the actual value remains stuck at the same value even when the valve is being activated, then the problem is either a mechanical issue with the valve or there is a cable/contact problem.

Best regards, Rainer.

Tip: Like the mass airflow sensor (MAF), the AGR valve should ideally be installed by the original equipment manufacturer (OEM), which in your case is likely Pierburg.

Rüdi wrote:

Tip: Like the mass airflow sensor (MAF), the EGR valve should ideally be installed by the original equipment manufacturer (OEM), which in your case is likely Pierburg.

While my EGR valve in my A6 4F, when replaced with an aftermarket part at 1/3 of the price, always lasted for exactly the same amount of time as the original part.
The plastic gears would always break at a specific point, regardless of which part was involved.

It depends, therefore.

Best regards, Rainer.

Rüdi wrote:

Tip: Like the mass airflow sensor (MAF), the EGR valve should ideally be installed by the original equipment manufacturer (OEM), which in your case is likely Pierburg.

Well, you were probably right in this case. After a wrong module was initially delivered/shipped for my Skoda, I installed the correct one, and so far, I haven't received any error messages during a 10 km test drive. I'm going to drive at least another 100 kilometers to make sure the problem doesn't reappear.

It's quite a mess, because with similar background stories, some threads from other forums also featured aftermarket AGR modules/valves. It probably only has to do with the motor or its potentiometer.

I'll probably only be sourcing these modules directly from VW from now on. Price difference in this case: €240.

I'll drive it again tomorrow and report back.

Regards,

Lukas.

The OE (Original Equipment) part from VW doesn't necessarily have to be used; they don't manufacture it themselves, it's just from the same manufacturer.

I've also learned some lessons the hard way with AGR components of unknown origin. Most recently, it was with a Lupo with an AUC engine. I ended up installing a used Pierburg part, and everything has been fine since.

Okay, so both of the original VW parts have Bosch stepper motors, and the housing and radiator, but I don't think any other brand was used. There was nothing stamped or printed on the MagnetiMarelli motor, which is already suspicious. Now I have to deal with the hassle of trying to return this thing. Taking it out and putting it back in isn't a quick job either. Axle carrier needs to be removed, DPF needs to be removed, driveshaft, oil supply line to the turbo, and intercooler hoses.

It's definitely running smoothly now, having covered 60km without any issues.

Thank you for your support.

Regards,

Lukas.

Thank you for the feedback!