VW Golf 3 Immobilizer Wiring Diagram - 1994

Hello forum,

My wife's Volkswagen Golf occasionally malfunctions; it sometimes turns off and won't start.
Starter motor is turning, no warning lights are illuminated, but the engine won't start.

He's already been to the workshop three times, and it has cost 400 euros.
The error is still there.

Nowadays, I prefer to troubleshoot and find the errors myself.
Now I think I've narrowed it down.

The connection for terminal 15 is not coming from the ignition switch to the central electrical system.

The 1.5 mm² black and white cable connects to a 2-pole connector located behind the main electrical panel.
From there, turn left and go uphill towards the vocational training center (WFZ), then come back down.
into the second pin of the plug and from there into the central electrical system.
Measurements have revealed that in the event of a fault, there is voltage present on the return cable.
There is no tension.
If I bridge all four of these cables, the Golf works perfectly fine.
Apparently, terminal 15 in the control unit will be switched again.
Is this a deliberate action or is it due to a faulty connection? There's also a relay clicking near the WFZ (presumably a specific component); can that be replaced?
What could be the reason why terminal 15 of the WFZ is not being activated?
Is there anything wrong with simply soldering these four cables together to put an end to this problem?

According to my wiring diagram called 'Now I'll help myself,' terminal 15 is actually supposed to be connected directly.
from the ignition switch to the central electrical system. But in reality, it probably looks different. Does anyone have a wiring diagram that shows what this detour is supposed to achieve?

I found this in the forum:

According to Volkswagen's documentation, a Digital Wireless Access (DWA) system with Window Film System (WFS) was available starting in January 1994.

The occupancy is:
T12/1 1.0 A, normally open/closed relay for starter motor.
T12/2 0.5 gn connection, cable harness, central voltage.
T12/3 1.0 rt/ws at 17 (let's see where this goes).
T12/4 1.0 br Mass DWA.
T12/5 0.5 red/green to T32/9 - Check lamp DWA.
T12/6 available.
T12/7 0.5 mm terminal block, brass/white connection, push-button contact switch.
T12/8 0.5 mm pitch - Connector for horizontal relay module - Switch.
Trunk lighting.
T12/9 0,5 br/bl - Steckv. ht Relaisplatte - Kontaktsch. Trunk.
T12/10 0.5 gn Connection, wiring harness, central locking system.
t12/11 1.0 RT sig 91 up PLUS 30.
T12/12 0,5 br/rt auf T4/3 - Kontaktsch. DWA

T8/1 1.0 sw/ws Left turn signal.
T8/2 1.0 sw /gn Turn signal, right.
T8/3 1.5A push-in connector, high temperature. Relay module connected to Plus 15.
T8/4 1.5 mm² black/blue connector, high temperature. Relay terminal block. Ignition switch with 5 connection.
T8/5 1.5 mm² screw terminal to horn.
T8/6 1.5 rt/bl on Sight 91 plus 30.
T8/7 connector, high temperature relay module for MSTG.
T8/8 0.5 g/cm³ on KPR. However, there's still a lead pipe on the TDI 1.0.
ge/gn up plus 15.


The connectors that are relevant to me are the t8/3 and t8/4 types.

Regards,

Michael.
*I hope that a competent person reads this.*

Hello,
Okay, I had the same problem with my Passat 1Z, manufactured in July 1994. Here's what happened in my case:
The anti-theft system has a contact on terminal 15 that provides voltage. This is intended to prevent the car from starting in case of theft. This contact probably switches off intermittently due to a cold solder joint in the alarm control unit. I then simply bridged sw/bl T8/4 (which comes from the ignition switch to the alarm system) and sw/ge T8/3 (which goes from the alarm system to terminal 15). Also, T2d/1 and T2d/2. In my case, this doesn't cause any further issues except that in the event of an alarm, the car would start if the ignition lock is short-circuited. I don't know if it's the same on your Golf. I don't have a WFS.

Hope I was able to help!

Yes, I also think it might be a DWA in my case...
What does 'DiebstahlWarnAnlage' even mean?

That's exactly what I intend to do, and it seems to be working well so far.
I was just worried that the alarm might go off at some point.
Since I essentially bypassed terminal 15.

A schematic diagram would be really helpful.
Why isn't this included in the book 'Now I Help Myself'?
'Published? Legal reasons? To prevent car thieves from...'
Do you have instructions on how to bypass something?

Regards,

Michael.

Hi there,

My first Passat, manufactured in 1995 and equipped with an alarm system (DWA), also had this problem. I then removed the control unit for the DWA, which is located behind the light switch in the Passat, and resoldered the cold solder joints on the relay. The error disappeared afterwards .

Best regards, Gregor.

That would also be possible, of course.

It's in the same spot for me too.

But I think I'll just bypass that part.
Then there will be no more loose connections.

I might also completely re-solder the circuit board.
Just out of interest, I'm trying to see if I can find the cold solder joint.

Can you open the control unit of the car alarm system and take a look inside?
Or is this part already cast and can only be soldered from the bottom?

Regards,

Michael.

I opened up the device (it still uses standard electronics, no surface mount components).
Clearly visible was a completely broken solder joint on the...
Relay closes contact 15.

After soldering, verschandeln it up .

But I still managed to bridge 15 gaps, so hopefully this is the end of it.
someday it starts...