Think you're right on the fault codes inhibiting the adaptation. 

 

Glad to be of assistance, I feel sure that you'll let us know the outcome. 

Just thought I would finish off this topic with the result. Went to GSF to buy the earlier EGR valve. The guy there said no way. Won't work. So I told him the correct one I bough on 27 aug didn't adapt. He looked it up. Said you bought a Vtech one from us. They're rubbish. Buy a Pierburg. So I did. Ran VCDS and it adapted first time with no bother at all.

 

Moral of the story. Vtech are rubbish. Pierburg are fine.

Lessons. You can buy brand new and get faulty parts.

Gains. I now know quite a lot more about EGR valves, how they work and fault chasing.

 

Nigel

 

Wonder what the 1.94V business was all about?  Was that with EGR connected to the loom or not? I assumed not at the time you were measuring.

 

Plug disconnected. Will try probing the wire with it all running if this rain stops.

Pierburg EGR part number is 7.28248.17.0 That's for BBZ engined 04 Fab chassis 6Y 7 44131231

Edited 8 September, 20178 yr by LB123
Edited to add part number

Grumble. The saga is not resolved. After MoT and 50 miles the engine light is on again and ECU shows a fault code for EGR excessive flow. Drives fine but the idle is rough as rats!

 

16786  - EGR System

P0402 - 35-00 - Excessive flow

Readiness; 1010   0101

 

I think the rough idle is due to excessive flow. The fault I'm beginning to think lies in the loom or the ECU. Both a pain to diagnose and remedy. That 1.94V is bugging me. I am thinking it should be 5V.

 

Nigel

Just curious, sorry if not welcome. Are you getting the 5 V reference on the MAF and Cam sensor too (pins 3 and 1 respectively I think)? I believe that 1.94 V should be 5 V all the time.

Just checked. Yes there's a 4.94v on one of the MAF pins and cam sensor pins.

With the EGR plug connected the pins read as follows;

1. 12.3v

2. 4.94v

4. 0.0v

5. 12.3v

6. 1.26v

So there is a near 5v reference voltage in each.

Guess that clears the loom and ECU perhaps.

I'm baffled. It ticked over best in its unrepaired state. Beginning to think I should have just ignored the warning light as the car was running better than it does now.

I'd say the ECU is fine, wiring can be tricky. In current carrying circuits voltage can still get through even if current can't (in the case of this component that would be the solenoid).

 

Does your model allow actuator tests? If so, run the EGR test and check the measurements while that is happening (if it happens at all). What I think should happen (bear in mind I don't have documentation for your specific model).

1. stays at battery voltage

2. stays at 5 V

3. stays non-existent 

4. should stay at 0 V

5. should drop to 0 V when actuated and stay at battery voltage when unactuated

6. I don't know, this is the wiper of the position potentiometer, so should change in conjunction with actuation and un-actuation, but how I can't say.

 

That's what I'd do for now.

If the OP has performed adaption using VCDS, he could repeat that and make a note of the measured end stop voltages - would that be enough?

 

I think, no matter how logical/illogical it might sound, when I had an excessive flow being logged, I ran adaption again on the new EGR valve and the TB and I cleaned)

 

Edit:- nice to hear that GSF don't think much of their "economy" range of bits - I've never been tempted, though GSF is 30+ miles away and ECP is only 10 miles away - though I do avoid their special own name stuff as well - except their brake cleaner and AC cleaner.

Edited 15 September, 20178 yr by rum4mo

2 hours ago, LB123 said:

Just checked. Yes there's a 4.94v on one of the MAF pins and cam sensor pins.

With the EGR plug connected the pins read as follows;

1. 12.3v

2. 4.94v

4. 0.0v

5. 12.3v

6. 1.26v

So there is a near 5v reference voltage in each.

Guess that clears the loom and ECU perhaps.

I'm baffled. It ticked over best in its unrepaired state. Beginning to think I should have just ignored the warning light as the car was running better than it does now.

 

Relax, when you cleared the CEL you also cleared the dynamic map, give it a while to relearn all the correct values again and it'll be better than ever.

You are saying to wait. Not clear the fault codes. Leave it to relearn the dynamic map adjustments and the engine light will eventually go off? How long will this take?

I had no idea that clearing the CEL wiped the 'learning'.

No, I'm saying yes, clear ALL the fault codes since you've now fixed the problem, this also wipes the dynamic map of which the EGR is a part.

 

If you haven't already cleared the codes then that's why it's running rough.

 

It takes about an hour of mixed driving to write a stable new dynamic map.

Sorry. I think I'm not getting it. I did not know that clearing codes wiped the dynamic map.

I have done perhaps three hours of driving since fitting and adapting the new EGR successfully. The CEL came back on after about an hour driving. I have cleared it about four times but each time it comes back on after a few minutes.

I will drive it more and see what happens but although it's fine over about 1500 rpm and goes well and smoothly the idle has got worse.

Check your brake servo vacuum hose.

OK. Will do. You are suggesting unmetered intake air leak?

Yep. My understanding (from a log of my Polo/BBY) is that the EGR valve is closed below 1500rpm. That makes me doubt it's involved in your described behaviour. 

Interesting but relevant? Doesn't look big enough to let in much air although enough to reduce servo vacuum. Rest of hoses are good. (Explains why the normally very fierce brakes are a little more controllable). I will seal temporarily and have a drive.

Edited 16 September, 20178 yr by LB123
Correct spelling

I don't know what I was thinking about when I edited my last posting on this thread, but when I was getting low EGR valve flow being logged, I cleaned up the EGR port in the TB area, ran adaption on the original EGR valve and the TB and everything returned to being okay  right away, no low flow EGR warnings as you are finding.  Quite a few months later, I checked the condition of the MAP sensor and for convenience replaced it with an earlier version as the original was badly covered with gunge, the idea was to take some time to clean up the original and swop it back in, that never happened.  Again after a few more months, In connection with another issue, and as I had grabbed a NOS VAG EGR valve from ebay when one turned up cheap, I fitted that and ran adaption on it, the car was happy enough with that right away.

 

One thing I did do was to replace all the associated gaskets when I checked the original EGR valve and again when I replaced that EGR valve with a new one some months later.

I cleaned throttlebody and EGR pipe and replaced gaskets. Did TB and on the second EGR valve adaptation, both successfully. Found the split in the hard portion of the servo hose this morning and temporarily sealed it. So I cleared the code and it's taken 15 miles of town driving for the codes to return. Same again; Idle rough as rats. Almost stalling.

16786  - EGR System

P0402 - 35-00 - Excessive flow

Readiness; 1010   0101

Hello everyone,

 

I know this topic is nearly 7 years old, but maybe someone still can help me. I measured the pins of my EGR valve.

 

1. 12V

2. 5V

4. 0V

5. 2V

6. 0V

 

I cannot adapt the EGR, because it doesn't even ''clicks'' when the adaption is running and it is only 3 years old.

 

I do not know if I have to buy a new one, but the voltage on pin 5 (2V) is bothering me, because I don't know if it should be 2V, 5V, 0V, 12V or any other voltage.

 

I need help in this case, I could not find anything relevant for me in other threads.

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 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 that pin 1 isn't reaching the ECU?

Thank you.