Hello everyone,

My car is a 2006 Fabia Classic 1.2 HTP model. Some time ago, the check engine light came on and showed a P0403 Open Circuit error. The EGR valve was first replaced with a Delphi brand one, but after 15-20 km, the P0403 error reappeared.

Then it was replaced with an original Pierburg, the error code cleared, and after another 15 km, the check engine light came on again and showed the P0403 error.

Measurements i took with a multimeter:

With the valve not connected to the EGR socket and the ignition on, and the engine off:

Pin 1: 0.24V (With the ignition on and the engine off, should I be seeing 12V here?)

Pin 2: 5V

Pin 3: Empty - not used

Pin 4: 0V

Pin 5: 4.33V

Pin 6: 0V

First of all, I want to ask; are these values normal? When I try to perform an adaptation in VCDs, the 0.70V values in the first box and the 4.40V values in the second box remain unchanged, resulting in an adaptation error within 5 seconds. My other question is: When the valve is not installed, and I check the pins on the ECU socket from the EGR socket, I hear a beep sound on 4 pins except for pin 1. I don't hear a sound from pin 1 on the ECU socket. Could it be normal that pin 1 isn't reaching directly the ECU?

Thank you.

Don't have access to circuits right now, but pretty sure one side of the solenoid should have ignition switched 12V on it.

Check cabin fuses one by one, especially ones that may be marked ambiguously on the fuse card or in user manual.

Photograph the current layout of the fuses before removing any, as a reference in case of "wait, which slot did I pull this one out from?" moments.

12 minutes ago, Breezy_Pete said:

Herhangi bir sigortayı çıkarmadan önce, sigortaların mevcut yerleşiminin fotoğrafını çekin; bu, "Acaba bu sigortayı hangi yuvadan çıkardım?" gibi anlarda referans olarak kullanılabilir.

Hi Pete,

Thank you for your answers. I found a previous comment you made about the Fabia 1.4 16v BBZ. I think it's the same for the 1.2, but your opinion is important to me as well.

Thank you very much.

“Try pin 1 to battery negative/chassis, should be 12ish V, same as what you might measure at fuse 7 with ignition on.

Wiring as follows:

EGR pin Wire colour(s) Destination/source

1 Black/red Ignition 12V via Fuse 7

2 Red/green +5V (from engine ECU, I should think, working on that, yep pin 98)

4 Brown/blue 0V/earth, also to ECU pin 108

5 Purple/white ECU pin 114

6 Green/white ECU pin 100

Try pin 1 to battery negative/chassis, should be 12ish V, same as what you might measure at fuse 7 with ignition on.

Wiring as follows:

EGR pin Wire colour(s) Destination/source

1 Black/red Ignition 12V via Fuse 7

2 Red/green +5V (from engine ECU, I should think, working on that, yep pin 98)

4 Brown/blue 0V/earth, also to ECU pin 108

5 Purple/white ECU pin 114

6 Green/white ECU pin 100”

For your engine, fuse #17, 15 Amp rated is the supply to check with ignition/contact on.

I wonder if this has been checked at some time in the diagnosis, and put back in the wrong position?

Edited 20 March20 Mar by Breezy_Pete

Hi Pete,

I'll check as soon as possible.

Thanks.

Hi Pete,

I've attached a photo of the fuse panel. Do you think there's a mistake?

Thank you.

It should be that ringed one in top row I think, check if it has blown. Wiring info said 15A rating, not 10A.

Hi Pete,

After changing the fuse, 12V came to Pin 1, thank you very much. Adaptation was also successful in the VCDs, even though the voltage and load values didn't change. After that, I got the P0403 error again 😔

Keep playing with it, sometimes you just need to do something twice!

Hi Pete,

I apologize for bothering you. I've tried maybe 10 times, the adaptation is successful but the voltages on the screen (Vcds Lite 1.2) remain unchanged, and the adaptation is successful within 10 seconds. With the pin 6 socket plugged in and the contact open, the voltage is 0.75V. During the output test, it fluctuates between 0.80-3.80V with different voltages. Is it possible for the adaptation to be successful without the values on the Vcds screen changing at all, or is something going wrong?

Thank you.

I'm not sure.

Maybe I can check on my car soon.

I think there are some pre-conditions for the adaptation, like perhaps coolant temperature being >80°C, I can check that this morning in a document I have.

Have you checked the steel output pipe at the point it discharges under the throttle body? Blockage there may be preventing any EGR flow.

Ignition on, engine stopped.

That is all I'm seeing. No reference to coolant temperature. (My) Memory failure.

Hi Pete,

I'll check.

Thank you again 👍