[Joda]

Hi!
I have in my garage a Skoda Octavia 1.6 TDI year 2011. with a CAYC engine.

The problem is:
The car was in limb mode because the P040800 - Exhaust Gas Recirculation Sensor B Circuit High
- Permanent
was in the memory.

We changed the whole EGR system with a new one.

Now we have another problem:
The P040300 DTC comes up and the car is also in limb mode but
sometime I can delete the error and the car is fine until I didn't
drive the car for a longer period over 3000rpm.
Then the glow lamp is shining on the dash and the car is in limb mode
and the P040300 is again on.

But when I put the old electromotor from the old EGR system to the new EGR
system then I got back the error P040800.

When I put back the new electromotor then I got the error again P040300.

The P040800 should be the G212 part but what is it?
The P040300 should be the N18 part but what is that??

So, what is actually going on?
Any idea?

Thank's...

[bobdinro]

Make a log of your DTC and post it.

[Joda]

This is the new DTC from VCDS 16787/P0403/001027 - Exhaust Gas Recirculation (EGR) Valve (N18): Malfunction.

This was the DTC before I changed the EGR whole system:
16792/P0408/001032 - EGR Potentiometer (G212): Signal too High

Is this N18 actually the motor?

"EGR Potentiometer (G212)"
Where is the potentiometer???
there is no potentiometer, the system is working with a rotary
position sensor IC from the family of 90316!

I changed the whole unit wit the cooling part too.

[bobdinro]

This is the new DTC from VCDS 16787/P0403/001027 - Exhaust Gas Recirculation (EGR) Valve (N18): Malfunction.

This was the DTC before I changed the EGR whole system:
16792/P0408/001032 - EGR Potentiometer (G212): Signal too High

Is this N18 actually the motor?

"EGR Potentiometer (G212)"
Where is the potentiometer???
there is no potentiometer, the system is working with a rotary
position sensor IC from the family of 90316!

I changed the whole unit wit the cooling part too.

As elsa say

The EGR valve -N18- consists of the mechanical valve, the EGR control motor -V338- and the EGR potentiometer -G212-.

Your part is new? skoda genuine part? wiring ok?

[mike_service]

Hi
just reset egr mass value with ODIS or VasPC and no more P0403 will be stored !

[Joda]

Your part is new? skoda genuine part? wiring ok?

No, the part is not new but from a donor car which has no DTC about the EGR
and it was in a working condition. The EGR system was tested before it was take off from the donor car.
It is a genuine part.
The wiring was checked and ok. But I will tomorrow check again.

Is the motor driven by PWM or is it a simple DC 12V driven motor?

I have ref. 5v between pin 1 and pin 3.
On pin 5 I have a 4-4.5V on my DMM.

Between pin 2 and pin 6 I have on my DMM a voltage spike
up to 9-11v then it go back to zero-almost zero when the ignition is on.

Should I check with scope for PWM signal?

Can I reset egr mass value with Delphi DS150 or with VCDS?
If it is possible with VCDS any description for that would be nice.

Can somebody send me a wiring diagram from Elsa for this type of Skoda?
Because I use the wiring diagram from a VW car with the same CAYC engine.
That should be the same, or?

The N18 should be the motor which is actually V338 in the VW diagram.
The G212 should be actually that half gear with the magnet on it?
Or is that the PCB which is on the motor?

The IC 90316 which is the rotary position sensor, can be set to analog output
and pwm output even to programmable output as a serial data out.

What type of signal should I expect on the Pin 5? Analog or PWM or some sort of
data output?

Thanks guys for help.

[golf481]

Hi. p0403 is a common problem throughout the VAG group, with the 1.6l + 2.0l common rail diesel engines. there is a known TPI (common issue) with these, and the proper fix for these is a new EGR cooler, with a software update for 01 - engine. the cause is due to the egr cooler interally leaking coolant, thus burning coolant within the EGR system causing the potentiometer/valve to stick either open/closed causing limp mode. on a few cases ive also seen the roller (behind the black cap on the egr cooler itself) break/fall off, causing the potentiometer to not adjust. hope this helps

edit: also it would be with checking the vacuum system which also operates the other valve on the cooler as there have been cases of pipes split/Crk/twisted or just been eaten by a mouse or something.

[Joda]

Hi. p0403 is a common problem throughout the VAG group, with the 1.6l + 2.0l common rail diesel engines. there is a known TPI (common issue) with these, and the proper fix for these is a new EGR cooler, with a software update for 01 - engine. the cause is due to the egr cooler interally leaking coolant, thus burning coolant within the EGR system causing the potentiometer/valve to stick either open/closed causing limp mode. on a few cases ive also seen the roller (behind the black cap on the egr cooler itself) break/fall off, causing the potentiometer to not adjust. hope this helps

edit: also it would be with checking the vacuum system which also operates the other valve on the cooler as there have been cases of pipes split/crcked/twisted or just been eaten by a mouse or something.

Hi!
Thank's for this informative answer.
I checked all the mechanical part, electrical part and the vacuum valve - pipe too.
Everything is moving and working in a perfect meaner.

The diag equipment says to me does there is a malfunction in the N18 part.
I disconnected all the electronic parts which have any connection with the EGR unit and checked which one is the N18.

There are only two options to disconnect.
1. The motor which have a rotary sensor electronic integrated pcb
2. The EGR cooling vacuum solenoid

When I change the new motor on the egr unit with the old one from the
old egr unit than I got the old DTC which was when the old egr unit was fitted on the car before, that DTC was P040800.
So, now, I have on the car a new egr unit + I put the old motor back then I got also the P040800. I assume the problem is not in the mechanical part of the egr unit but in the electronical part of the motor, even if I connect DC 12V to the motor terminal the motor is working great.

When I put the new motor on the same egr unit then I get the P040300 DTC.

Conclusion, the DTC is generated actually by the rotary sensor electronic which communicate with the ECU through the motor connector pin 5.

Could it be does the N18 part is actually the motor wit the electronic on it and not the whole egr unit?

I'm a bit confusing:
- old egr unit have the DTC P040800
- new egr unit have the DTC P040300
- interchanged motors then I get the old DTC P040800 on the new egr unit.

I also can't find in my diag tool any option to adaptation of this egr unit.
I use Delphi and VCDS for this task.

[golf481]

Heres a wiring diagram for a cayc engine.

[Joda]

Is the motor of the egr valve N18 driven by 12V DC or is there a PWM controlled voltage output?

The car is actually right now not by me and I can not check that line.

Thank's