2.0 TDI EGR Issue

[Muran]

Hi All,



I am having a massive problem with my EGR which I can't resolve for few months now.



Few months ago, while I was driving on motorway, my car went into limp mode and got coil light flashing. When I turned off my car, fault disappeared and I was able to continue my normal drive for another few km, then car went into limp mode again. When I have scanned an errors, both were related to EGR so I after reading forums etc. I have decided to replace it with brand new part ( same as original made by Valeo ).



I have done adaptation on VCDS and run all test - no issues, so I went for a test drive. Unfortunately after 25km, car went into limp mode again.. and got same error codes as initially.



My mechanic suggested to change N18 and N75 valves as these might have caused some issues. Both have been changed but no luck with fixing this issue...



I have also changed Mass Air Flow sensor and DPF pressure sensor too ( suggested by some colleague ) but still the same.



There were few topics where people were reporting faulty new EGR valve ( non-OEM ), so I thought I could have been unlucky with my OEM part too ! I have purchased OEM used EGR ( tested ). Done another adaptation but got same errors...



When I am running tests on VCDS, I can hear that EGR works (electronic) and one which lifts by vacuum ( it does fully open and shut ).





Could someone suggest what else could be a problem ? I have no idea what else should I change. I attach log from my car with error codes. Some values have minus % so it does looks strange... I had the same on new and current EGR.



Other mechanic suggested checking injectors but can't see these would cause an issue.



Just to add - I didn't get this error while driving in town or during short distance. It only appears after 25-30km. Just once, I have managed to do 80km without an error - I was driving constantly around 140km/h.




2 Faults Found:
4891 - EGR Valve (N18)
P0403 00 [096] - Malfunction
Intermittent - Not Confirmed - Tested Since Memory Clear

4892 - EGR Valve (N18)
P0403 00 [096] - Malfunction
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 307836 km
Date: 2024.04.06
Time: 18:33:30

Engine RPM: 1977.00 /min
Normed load value: 30.6 %
Vehicle speed: 88 km/h
Coolant temperature: 90 C
Intake air temperature: 25 C
Ambient air pressure: 990 mbar
Voltage terminal 30: 14.380 V
Unlearning counter according OBD: 40
Air mass: actual value (mg/stroke): 363.1 mg/stroke
EGR Vacuum Regulator Solen.val.: activation: 15.00 %
EGR Solen.val.: actual value: 37.44 %
EGR valve: offset closed: -4.11 %
Actuator for high pressure EGR: status-Bits 0-7: 55
Actuator for high pressure EGR: status-Bits 0-7: 0
Actuator for high pressure EGR: status-Bits 0-7: 0
Actuator for high pressure EGR: status-Bits 0-7: 0
High press EGR actuator: actual unconditioned volt val: 3171.8 mV





Thanks in advance for any help !

Log-WAUZZZ4G3DN042614-307869km-191300mi.txt

[Crasher]

So you fitted the full Valeo cooler 700436 and then a used 03L 131 512 DN

[Muran]

Hi Crasher,

Yes, that's correct

Thanks

[Crasher]

I have been fighting the same type of ECU with a similar problem. It came in from another garage with the auto start not functioning and a code for the manifold flaps which were new aftermarket, they reported as being stuck open and stuck closed at the same time. I told them to fit a genuine manifold and no luck so they brought it back and they had fitted Febi which should be OK.

With the auto start always generating a code I could not perform basic settings and I decided it was a faulty ECU but the owner would not spend that much so I fitted and coded a used ECU which cleared the auto start fault but not the manifold.

Convinced it was the ECU I bought another and it was the same but now with other codes for the N75 and G70!

I sent the second ECU to ACTronics and they said there was nothing wrong with it but when I plugged it in I got two more codes for the air box flap and EGR valve… FFS! I took the cover off the EGR motor and it was full of oil and the gear stripped and the air box flap solenoid was unplugged so they had been faulty with three ECU’s and not shown up.

I fixed the new faults and fitted a genuine manifold, performed basic settings (the flap motor worked) and then went back to the fault codes and now had the stuck open/stuck closed faults right back from the first manifold but if I plugged in the Febi manifold I got a range/performance error, this was getting stupid.

A Polish chap I know came around and dealt with the fault code sending it where it belongs.

I know it is the ECU but the owner won’t spend that amount of money on the car.

[Muran]

Thanks for your response. Is there any way to say that my ECU is faulty ? What tools are needed to code 2nd hand ECU?

I think my original EGR was faulty as EGR vacuum valve had loose metal seal(?) .

Screenshot 2024-04-07 180125.jpg

Screenshot 2024-04-07 180125.jpg

I seen that EGR adaptation looks different on VCDS on non-UDS modules. I am going to have ODIS soon - do you know if there is an another option for adaptation?

It is really annoying as can't go anywhere outside town as driving in limp mode is not ideal..

Thanks

[Crasher]

I was able to match a used ECU using ODIS with GEKO security access but this is not always possible. My Polish friend Lucas comes to my rescue for odd requests… sometimes you have to give up and find an alternative way out.

[Muran]

I have got ODIN yesterday but adaptation looks the same as on VCDS, so can't see it did help.

Any idea why this value is minus? Is that correct?

EGR valve: offset closed: -4.11 %

Where could I find diagram for EGR plug so I can check if voltage is correct on all pins etc. ?

Thanks
Marcin