Hello,

I have one problem with my polo classic model year 2000.
I drove it a couple of days ago and everything was normal. Yesterday I tried to start it up and car just cranks but it is not starting. When I was starting it before, glow plug light always lit up for a couple of seconds but now glow plug light does not light at all and I don't hear relay click. The battery is new and voltage is good, I opened fuse box and all of the fuses are good. I don't know which relay is for what, I read on the forums that relay 109 could be bad but I don't have that relay number.

What could be the cause of this and what should I check next ?

SDI or TDI?

 

The fuel pump relays do fail over time. They're nothing special though, and a replacement shouldn't cost much. Try giving it a tap with something metal, or you can bridge them out as a temporary measure. I can't think which one it is without looking, but there's no harm in giving them all a tap. 

 

 

Sorry, I forgot to mention it is 1.7 SDI engine. 
It is pretty hard to find out which one is for what, I looked at some photos on the Internet but the numbers on my relays don't match.
For example, this PHOTO resembles a fuse box but for example, relay number 167 in this photo is relay 103 inside my fuse box. 
I tapped every one of them and the problem still persists. Could it be that ECU is not getting power or maybe it is gone bad ?

You haven't done anything to the airbag system have you ? as the airbag ECU controls the fuel shut-off relay #405 in this picture and it's not a normal relay as it has 6 pins to account for the airbag ECU control,  There are 7 fuses for the engine controls #1, 2, & 6 50 amp fuses on the battery box and fuse #1 10 amp, #23 & 24 5 amp, & #37 30 amp in the interior fusebox, the fuses on the battery box are known to fracture and a visual check doesn't always show the crack

 

1 hour ago, nige8021 said:

You haven't done anything to the airbag system have you ? as the airbag ECU controls the fuel shut-off relay #405 in this picture and it's not a normal relay as it has 6 pins to account for the airbag ECU control,  There are 7 fuses for the engine controls #1, 2, & 6 50 amp fuses on the battery box and fuse #1 10 amp, #23 & 24 5 amp, & #37 30 amp in the interior fusebox, the fuses on the battery box are known to fracture and a visual check doesn't always show the crack

No I haven't touched airbag at all. I parked the car a couple of days ago and haven't touched it since yesterday when I tried to start it.

I'm looking at this relay plate in this photo and it seems like it is not the same as mine. One more thing, I don't have any fuses on battery inside engine compartment, just the battery.

I took the photo of my relay plate, I hope it will help:

RELAY PLATE PHOTO
Note: for some reason blue fuse in bottom left below relay number 19 looks like it is blown but it is not, probably the angle of the camera.
 

That picture of the relays is not from a 2000 year more like a 1997 or earlier ?? and that will explain why there are no fuses on top of the battery

2 minutes ago, nige8021 said:

That picture of the relays is not from a 2000 year more like a 1997 or earlier ??

I don't know, inside car ownership card (I don't know how you call it in English) says it is manufactured in 2000.
INTERIOR
This is how it looks on the interior, it is not facelifted as 6n2.

This is your relay panel, if the terminal 30 relay has failed it will stop the engine ECU from getting any power and that is why you are not seeing the glowplug symbol lighting up when you try to start 

 

Also the picture of the speedo that is a pre 1997 version due to the position of the fuel & water temperature gauges 

I tried new relay number 3 and problem still persists.
Do you, by any chance have pinout of the ECU for 1.7 SDI engine so I could verify that ECU is not getting power ?

Can you confirm what engine code you have so I can ensure it's the correct diagrams

17 minutes ago, nige8021 said:

Can you confirm what engine code you have so I can ensure it's the correct diagrams

Where I can find engine code ? I think it is AKU but I'm not entirely sure.

Edit: Sorry I meant AKW

Edited 14 March, 20224 yr by LoOdaK

Can you feel/hear that "Terminal 30 relay" when you put the ignition to the ON (not start) position ? 

 

ECU Pin 47 12v Ignition ON supply via fuse #14 15amp 

ECU Pins 28 & 2 12v supply via that "30 supply relay" it also splits and feeds the following, Coolant heater relay, EGR valve, Speedo sensor, Fuel pump metering valve, Throttle body switch & if fitted Cruise control brake switch

Okay I measured pin 2 voltage and it shows about 9V so there is some kind of a voltage drop. Could that cause ECU to not work ? I suppose ECU has some kind of under voltage lockout system so that could explain this behavior. What could cause this voltage drop ?

Is it only on pin 2 that it is 9v ? I can't imagine the ECU is going to like 9v and almost certainly wouldn't work

 

 

As you can see the supply comes out from the "30" relay on plug G1 pin 10 then splices together to feed the two pins on the ECU and the other users I mentioned before.

 

I would remove the connector G1 from back of the relay panel and measure the resistance from pin 10 to the ECU Pin 2 & 28 and see if there is high resistance causing the voltage drop, then if there is, it will be a case of undoing the outer wrapping of the ECU loom to find that splice point "F28" and repair as required

 

Picture of the back of the relay panel

 

 

I finally got car electrician to look at it (pretty hard to get to one where I live) and as it turns out, my ECU is bad. Water somehow got into it and when we wiggled and cleaned the board a little bit glow plug light came right away but car starts and stops immediately. I will try to find another ECU.

If I may ask, where did you find those diagrams ? Is there any program I could download ?

The engine starting and then almost immediately stopping is classic immobiliser kicking in and stopping the engine.

 

The wiring diagrams are from a program called ElsaWin, it is a copy of the main dealer workshop manuals for all VAG models from around 1994 to current, it can be found on some torrent sites to download, I bought a copy from eBay UK it is a very large program around 90 Gb and if you are running Windows 10/11 you have to run it on a virtual Windows 7  or you can go onto https://erwin.volkswagen.de/erwin/showHome.do  pay I think it is 7€uros for an hours use of the site and download all the relevant files for your car based on the VIN, as a matter of interest on your VIN what is the 10th digit it will be a letter ? 

2 minutes ago, nige8021 said:

The engine starting and then almost immediately stopping is classic immobiliser kicking in and stopping the engine.

Does that mean that ECU may not be the problem for starting and stopping the engine ? I mean ECU looked bad when we opened it.
 

 

3 minutes ago, nige8021 said:

The wiring diagrams are from a program called ElsaWin, it is a copy of the main dealer workshop manuals for all VAG models from around 1994 to current, it can be found on some torrent sites to download, I bought a copy from eBay UK it is a very large program around 90 Gb and if you are running Windows 10/11 you have to run it on a virtual Windows 7  or you can go onto https://erwin.volkswagen.de/erwin/showHome.do  pay I think it is 7€uros for an hours use of the site and download all the relevant files for your car based on the VIN, as a matter of interest on your VIN what is the 10th digit it will be a letter ? 

Thanks for the info. By the way I entered my VIN on some websites today and apparently car is manufactured in 1999, but inside my owners book it says 2000. I really don't know how that could be possible but it looks like it is hahah.

Here is my VIN: WVWZZZ6KZXR564295

By the way, thank you very much for your help and for your time

It is quite possible the water damage has caused the immobiliser problem or the low voltage you measured has meant the immobiliser & ECU have lost their matching, a reading of the fault codes might say "Start blocked by Immobiliser" 

 

Yes that VIN does confirm (XR) that it was built in Spain in 1999, strange that it has the pre 1997 speedo ?? but the 6K classic is more of a Seat Cordoba than a VW Polo 6N

VIN plate says that it is 6KV not 6K. I don't know if that makes things different.

12 minutes ago, LoOdaK said:

VIN plate says that it is 6KV not 6K. I don't know if that makes things different.

 

Your previous post said Z WVWZZZ6KZXR564295  that is the usual "filler code" used Digit 9: Z (fill-in digit) for Europe and most export markets, including Australia

Starting and stopping right away might be the fuel shut off valve. They don't last forever and the wire to them is prone to damage. Try taking it out and removing the plunger before refitting it. Not saying it definitely is that, but for the two minutes it takes, it's worth a go