2013 T5 - No crank situation

[elqwan]

Thanks for your reply. I hooked up a multimeter to the control wire and read 0 volts while the key was in the crank position. So I know at least there is no voltage at the very end of the wire. When I get my tone generator tomorrow I will trace the wire and see if I come up with something.

I actually had a broken engine mount a few months back, but I dont know how long it was like that for. I was replacing a broken tensioner and just happen to grab onto the mount and saw it was cracked. But the control wire does not seem to be anywhere near the engine block.

 

[elqwan]

Alright guys, here is where I am at. But before I start pulling more apart I need your help to confirm something. Because unless I am looking at the wrong WD then the J433 (507) and J434 (645) relays are not in the WD.

In the relay holder in the engine compartment underneath the battery I have two separate starter inhibitor relays. One is the J433 (507) Starter Inhibitor Relay and the other is the J434 (645) Start inhibitor relay, clutch pedal switch. (There is one more start inhibitor relay but that J207 but that is not for my specific model)

Relay 645 has 12 volt power to the 30 pole on the relay as it should but
Relay 507 has 0 volts to the 30 regardless if the key is on, off or in crank position. BUT it gets battery voltage to the 86 pole.

Is there a reason the 507 start inhibitor fuse does not have power to the 30 pole, but has power to the 86 pole? I cant follow the WD because I dont see this relay on the WD. And which start inhibitor relay sends power to the starter, 507 or 645? I dont want to start jumping relay terminals without knowing where they go first.

Here is the engine compartment relay holder diagram.

https://imgur.com/j27JKpO

 

[dnoermann]

Alright guys, here is where I am at. But before I start pulling more apart I need your help to confirm something. Because unless I am looking at the wrong WD then the J433 (507) and J434 (645) relays are not in the WD.

Page 1680 of K0058984400-Grundausstattung__ab_August_2009.pdf shows exactly those Two Relais.
Like i said in my first post.

J434 gets 12V on Pin 2 of coil via Fuse SB23 which gets Power form Klemme 15
J433 gets 12V on Pin 1 of coil via Fuse SB23 which gets Power form Klemme 15

The Engine ECU is than "Switching" the Gnd Signal to those two relais.

 

[elqwan]

Ok, my WD shows something slightly different, the relay numbers are not the same. I think this is why I am confused. I am in the correct section of my WD but for some reason it is different than the German WD. So relay J433 pin 5 should send power to the starter control wire. So theoretically if I put 12 volts to the 5 pin on J433 relay the starter should turn over. Or am I mistaken once again?

https://imgur.com/xLUTbYO

 

[dnoermann]

Ok, my WD shows something slightly different,

That is really strange.
Pdf Page 1680 which is Nr.171 / 16 in German Plan looks identical.
But
J907 is J433
J906 is J434

I believe we found Error in Translation.
But hey you are from Austria, so download the German Diagram, you can understand it.

 

[dnoermann]

I put 12 volts to the 5 pin on J433 relay

Yes

 

[elqwan]

Im an American living in Austria. I speak German but its easier for me to read an English WD.

So I put direct power to Pin 5 on J433 and nothing happened at all. I did not jump the wires from pin 3, I hooked a wire to the + battery and touched Pin 5, but nothing.

I got my tone generator and hooked it up to the control wire down at the starter and traced it back to pin 5 on J433, so the wire should be in good shape. No Idea why the starter would not go if I put direct power to Pin 5.

As I was typing this, I decided to try one more test. Keep in mind my battery is now a bit low. Since you need to remove the battery to get to the relay panel, I have jumper cables hooked up. So right now the battery is reading around 9.5 volts.

So my next test was to hook my voltmeter up to the starter control wire down at the starter, then I put direct battery power to J433 and only read around 6.5 volts. So there is a volt drop of 3 volts, and this is with the key off so no load. This leads me to think it is a ground issue, but as I mentioned in my first post I am able to hook a jumper wire directly from the battery to the starter and it starts no problem at all.

What am I missing here? What would cause a loss of 3 volts in that single wire? I guess the answer is that there is resistance somewhere in the wire. Does this relate to my no crank issue which started as an intermittent problem and then to no crank all the time?

 

[dnoermann]

3V Drop it really to mutch. (Assuming this drop was on the Cable between J433 and Starter and that is what it looks like)
Change the Cable.
As you see the Cable startes to be 4mm² from Pin 5 J433 ==> D210 (That is a Point where Cable is connected to 2,5 mm²) ==> Connector T10l Pin 1 and than to Starter Pin 50.
You can only Check easy if Connector T10l is ok.
As Test i would wire a new 4 mm² as compleete replacement from Pin 5 J433 to Starter Pin B and Test.
If it works, make it beautiful ....

And Load your Batterie ...

 

[elqwan]

Yup sounds like a plan. I am charging the battery tonight.

1 question just to be clear I am reading the WD correctly.
Lets work from the starter to the Pin 50.
Starter solenoid (2.5mm²) --->connection D97--->T10l Ten pin connector Light green ---> connection D210 4mm²--->Pin 5 on Relay J433

So the idea of putting direct power to Pin 5 would only work if all the other connections were good. I was under the impression that Pin 5 wire went directly to Starter Pin B. But that is not the case. So I need to start tracing these wires for a potential break.


- I just went out a did a resistance test of the control wire from the starter to pin 5. I did have two additional wires attached to each side of the voltmeter in order to reach the connection.
But I first tested the two additional wires and they had 0.000 ohms of resistance, then I hooked the wire up to the start control wire and read the resistance between between the 5 pin and Pin B and get nearly 4 ohms.
Since my voltmeter read 0.000 ohms when testing the leads, then the 2 additional wires attached to my meter read 0.000 ohms when tested and once I hooked them up to the 5pin to B pin I got 4 ohms. That should mean I have a bad wire or connection

I thought my tone generator would have picked up a bad wire, but who knows.

Does any of this make sense oder bin I ein trottel?

 

[dnoermann]

Starter solenoid (2.5mm²) --->connection D97--->T10l Ten pin connector Light green ---> connection D210 4mm²--->Pin 5 on Relay J433

Exactly right.

Does any of this make sense oder bin I ein trottel?

No Trottel.
For the Tonegenerator 4 Ohm is still ok. hey it is still one Digit Ohm, so not so high ...
And for shure under Load this 4 Ohm will rise.

 

[elqwan]

Alright sounds good. Tomorrow I will start tracing wires and see if I find something. I hope I find something. Maybe it was the same Marder that ate the wires for the add blue injector on my wifes Tiguan!!

Thanks!

 

[elqwan]

All fixed!

Here was my process. I checked continuity from T10L/1 and Pin 5 on J433 (all good), then from T10A/4 to Pin 5 (all good), T10 to T4 connector (all good). So now I knew the bad wire had to be from T10L/1 to the starter. After first examining in the engine compartment relay locations everything looked good. So then I began undoing the tape work from the starter back, I got about 10 inches from the starter and was able to pull the starter wire apart. Fitted up a new wire to fresh original wire which only began in the relay area in the engine compartment, it rotted itself back pretty far. But now it fires right up. I have an airbag light now, but that could just be from taking the battery out.

The WD is not always 100 percent accurate, for example the Relay numbers were incorrect in my english WD but correct in the German WD. Also the T10A connector was supposed to be light green but it is a light blue. But if you know what you are looking for you can see there are only a couple red wires coming from all of the connectors.

Thanks for all of the help. I for sure took the long way around, but I did learn a lot here. So thanks for that. Learning to read a WD is KEY!

I should add that you can't always rely on a tone generator as in my case. The generator told me the wire was good by sending signal throughout the entire wire, but clearly the wire was not good enough.

Paul

 

[Uwe]

I should add that you can't always rely on a tone generator as in my case. The generator told me the wire was good by sending signal throughout the entire wire, but clearly the wire was not good enough.

Yes, a tone generator is an excellent too for knowing which wire is which and determining whether there is at least some continuity, but it does show that the wire is capable of carrying current. That's why it is necessary to load-test wires as well.

-Uwe-

 

[elqwan]

Yes that is true. I wasnt really thinking in terms of locating wires as much as I was trying to see if the wire was broken. But load testing is for sure the way to go.
Thanks again to the people who helped out and led me to learn new things.