Hi

Trying to track down cause of poor running and would like to check the electrical inputs to the solenoid valve block (containing N18, N75 & N345 - think that's the lot unless there is anything else lurking in there).

 

I know what each of the vacuum pipes controls but can't find any info on the (6 pin) electrical connector, other than an old post which gives pin 2 as being to the N345 valve.

 

Anyone know what is what for the other pins?

 

Thanks

Edited 12 May, 20169 yr by Octy0GG

What's the part number of the solenoid valve block?

What's the part number of the solenoid valve block?

 

This is the one I bought. Used in a lot of cars including mine - Octavia BXE 105

 

Genuine VW 1.9 & 2.0 TDI Vacuum Solenoid Block  

 

Unlike earlier models, the Mk5 Platform as well as the Polo / Ibiza / Fabia vehicles have a combined Vacuum System, which controls the Turbo Actuator (N75) and the EGR Vale (N18)

Common symptoms of failure are boost issues, EGR / Emissions Faults or a buzzing / vibrating noise coming from under the bonnet

 

VW Part Number

 

6Q0 906 625 E - 6Q0906625 E - 6Q0906625E

 

6Q0 906 625 - 6Q0906625

 

 

 

To fit the following Engine Codes:

 

VW Caddy - BJB 105

 

VW Golf Mk5 - BRU / BXF 90, BKC / BXE 105, AZV / BKD 140

 

VW Golf Mk5 Plus - BRU / BXF 90, BXE / BKC 105, BEE 130, BMM / AZV / BKD 140

 

VW Jetta - BXE / BKC 105, AZV / BKD 140

 

VW Polo - ATD 100, ASZ 130

 

VW Touran - BRU / BXF 90, AVQ 100, BKC / BLS / BXE 105, AZV / BKD 140

 

Audi A3 - BXE / BKC 105, AZV / BKD 140

 

Seat Altea - BRU / BXF 90, BKC / BXE 105, AZV / BKD 140

 

Seat Cordoba - ATD 100, ASZ 130

 

Seat Ibiza Mk4 - ATD 100, ASZ 130, BUK / BPX 160

 

Seat Leon - BXF 90, BXE / BKC 105, AZV / BKD 140

 

Seat Toledo - BJB / BXE / BKC 105, AZV / BKD 140

 

Skoda Fabia - ATD 100, ASZ 130

 

Skoda Octavia - BJB / BKC / BXE 105, AZV / BKD 140

 

Skoda Superb - BXE 105, BKD 140

Edited 13 May, 20169 yr by Octy0GG

I should be able to find out for you from there. I haven't got wiring diags for octy2 but I am fairly sure some of the ones I've got will cover some of the ones cross-referenced.

OK, so from a Polo ASZ engine diagram from 2004-ish, we have:

N18, pins 1 & 2, pin 1 12V, pin 2 to engine ECU (pin 81),

N75, pins 3 & 5, pin 3 12V, pin 5 to engine ECU (pin 62),

N239 (Variable intake manifold flap change-over valve), pins 4 & 6, pin 4 12V, pin 6 to engine ECU (pin 61).

 

Each solenoid coil is shown with a resistor in parallel with it, presumably something to do with fault detection?

 

I don't find any reference to N345 in the Polo diagrams.  Will have a look at Mk1 Fabia ASZ one in a sec, but I expect it'll be the same.

Spoke too soon there...

 

On Mk1 Fabia they're in a different order.

N18 pins  4 & 6 (6 to ECU pin 61)

N75 pins 3 & 5 (5 to ECU pin 62)

N239 pins 1 & 2 (2 to ECU pin 81)

 

1, 3 and 4 12V as above.  So N18 and N239 swapped compared to Polo??  Must be an error somewhere??

Edited 13 May, 20169 yr by Wino

Wino

 

Many thanks for going the extra mile.

 

Have not done full tests yet but checked the voltages at the connector - disconnected from solenoid block, with key at run position but engine not running.

 

Pin 1:      12v

Pin 2:      3.51v

Pin 3:      12v

Pin 4:      12v

Pin 5:      3.25v

Pin 6:      3.26v

 

So definitely agrees with wiring diagrams regarding 12v pins

 

Slightly puzzles me how there is no ground to solenoid valve block, with plastic case and rubber mountings there can be no other ground.

Edited 13 May, 20169 yr by Octy0GG

The way it works is that each wire going to the ECU is connected to a transistor. This transistor is switched under software control, connecting that wire to ground inside the ECU (energising the solenoid coil as it does this). It may just be on/off, or it may be done in a Pulse Width Modified (PWM) way, allowing variable degrees of on-ness/off-ness. Have a look on wikipedia for a more thorough explanation.

 

Apart from establishing connectivity, which I think you've just done, I'm not sure how much you can do without an oscilloscope, and a specification of what is 'supposed' to be going on.

Think I might be getting somewhere - or possibly just brain is fried.

 

Did some output tests using VCDS

Looking at vacuum outputs from N75 (Turbo actuator) N18 (EGR actuator)

 

So started engine to build up pressure in reservoir then run tests with engine off (as required for these tests) but still with vacuum in reservoir.

 

VCDS output test cycles       on off on off ........ until you move onto next thing to test

 

For N18 vacuum gauge needle barely moved off zero - slight flicker if you really focused 

For N75, off gave 0 inHg, changing to on shot up to high teens dropping slightly until falling abruptly to zero for off, continued cycling but dropping each time.

 

Slightly concerned that N75 dropped, but thinking if pump was running to maintain reservoir vacuum this should not be a problem. 

N18 a bigger concern - surely it should have behaved in a similar way to N75.

 

Does that seem reasonable? or am I missing something?

 

Thanks

they work the opposite way round  generally   note the turbo goes to full vac until the revs/pressure start to build then backs off to prevent overboost

Hi, 
Can anyone help me please?
With this topic I discovered a problem of my car. The turbo actuator doesen't work fine. I checked the vacuum tubes and the system is ok.
I haven't 3.3V on 6q0906625 connector. I have 12V, 12V, 3.3V and 0.1V.
Can anyone say me what is the ECU that drive these 3.3V wires??
I would open it for check. I would also check the continuity of the wire. I will change the ECU if it resolve the problem but I don't know which is it.
Thanks a lot

Sorry..
I have a Polo 9n3 1.9 TDI (2005)

Engine code please. Look at the sticker on your upper cambelt cover. Three letters in front of the engine number. Example below.

 

Thanks for your reply

I'll check it but I haven't the car now.

 

However I think my engine is AXR.

 

I'm going to check the sticker as soon as possible.

For AXR in 2005 Polo there's only two solenoids inside the vacuum box, no N18 valve.

The N75 charge pressure control solenoid has its 12V feed on pin 3 of the connector, blue/black wire, and its engine ECU connection on pin 5, a lilac/white wire going to ECU pin 62.

The N239 Variable intake manifold flap changeover valve has its 12V feed on pin 4 of the connector, blue/black wire, and its engine ECU connection on pin 6, a brown/white wire going to ECU pin 61.

Edited 5 August, 20213 yr by Wino

many thanks!
I knew about only 2 valves.

 

Is this the ECU?

thanks

Yes, but extremely reliable internally, so wires and connections would always be best suspects if things aren't behaving.

Hi!

Yesterday I thought that the ECU was in error and then was it that pushed the wire to 0.1V. So I erase the ECU error. The line was to 0.1V another one time because the connector to 6q0906625C box was open and another error was in ECU. So I measured the pin 6 during the ECU error erasing procedure and.... the voltage went up for a moment then it went down to 0.1V because the error return. It is good?

I don't have a VCDS tool for drive the vacuum valve box via ECU but I think that I must replace the 6q0906625C unit. What do you think?

I discovered a second hand ones but it was of a polo with ATD engine. Is it compatible with mine AXR??

Thanks a lot

 

Attached the error before the first ECU erase

 

 

 

 

 

 

 

 

 

You need to measure the resistance of each wire between ECU connector and valve block connector. Close to zero Ohms is what you hope to see.

 

Unless you know that the wires have good continuity, it's difficult to know if the voltage at the valve block is 0V because the ECU is switching the valve fully on, or because there is no connection because the wire is broken.

 

Thanks

 

The continuity is ok 

 

Now I remember that a friend close the EGR for me a lot of years ago. He remap my ECU.

So, the 0.1V on pin 6 (N239 valve) can be ok.

Sorry!

I thought my friend close the EGR instead he fully open it?

 

What difference between engine code AXR and ATD?

Can I use the 6q0906625C unit from and ATD engine?

I don't think I understand the two systems well enough to advise you on all the differences, but the two parts diagrams show AXR having a 'throttle body' upstream of the EGR (item 3 here vacuum system; exhaust gas recirculation - Fabia(FAB) [EUROPA 2005 year] (7zap.com)). The ATD engine doesn't have this, but instead has a solenoid valve additional to the vacuum block (item 10 here; vacuum system; exhaust gas recirculation - Fabia(FAB) [EUROPA 2005 year] (7zap.com))  Note that this additional solenoid is described as N239 in one of the columns of that table.  

 

The wiring diagram section that covers both looks like this: and the * next to N18 is defined as "only on models with engine code ATD".  I wonder if that's an error, and that asterisk should be next to N239 on the diagram instead of N18?

That seems to make more sense, I think. What are the wire colours that you have, and which pin numbers of the 6-way connector do they come from?

 

 

 

 

 

 

 

 

 

 

Edited 7 August, 20213 yr by Wino

On 13/05/2016 at 07:58, Wino said:

Hi has any got the pin number for a n75 on a bxe edc16ecu 

 

What car, what year?

Hi mate it came out of that 

Iv put a asz 1.9tdi pd130 in my 2.0sdi caddy 

Caddy is a edc16ecu so I had to get the ecu out of a Sharan 2007 what is a edc16ecu so the sdi loom plug plugged into the Sharan ecu the sharan has a vac box and the caddy hasn't and I need the pin numbers to wire a vac box or n75 into the caddy can you help please