Brake Light Switch Wiring Diagram AFN vs 1Z

Hi,

I have a wiring harness that was originally designed for an AFM-MSG. With the AFN engine, the MSG requires two brake pedal signals, which must be achieved simultaneously using both a normally open and a normally closed contact.
I integrated an opening relay and a closing relay into the brake pedal circuit to simulate that.
"In the meantime, I've installed a wastegate turbo and switched to a compatible 1Z transmission. Unfortunately, since then, I've had an error code related to an implausible brake pedal signal, and consequently, the GRA (presumably a system related to the engine) is no longer working."

What changes do I need to make to the brake pedal signal to make the error message disappear?

Regards,
Jens.

Hello Jens,
Please provide the part numbers of the control units (I hope you have them).
Voluntarily installed a plastic box / MSA12; then it's better to use a suitable 1Z data set.
into the AFN STG).
Best regards, Micha.

Hi Jens,

If I can just get this right now, it's like this:
There are two options for the opening contact (connected to pin 20 of the main control unit).
To the best of my knowledge, the older F47 model is powered by a mass-produced engine, while the newer F47 model is powered by a Plus engine.

I initially connected the mass version and encountered the same problem.
You probably need exactly this version.

Best regards,
dieter

Data from the original MSG:
Vehicle registration number, year of manufacture: 1997.
MSA15
VW ET number: 028 906 021 GL


Data for the currently used MSG:
AHU, manufactured in 1997.
MSA15
VW ET number: 028 906 021 AT

dieter wrote:

As far as I know, the older F47 model is powered by a mass-produced engine, while the newer F47 model is powered by a Plus engine.

Hello Dieter,

Just the opener?
I don't have the wiring diagram memorized, but I believe that both of the relays I installed would either pass or block the +12V. I can take a look at how it's wired if you like.
Instead of switching +12V, the normally closed contact then disconnects the ground (or vice versa)?

Regards,
Jens.

Jens 16syncro wrote:

Just the opener?

Yes.

Jens 16syncro wrote:

However, I believe that both of the relays I installed are switching the +12V either on or off.

One provides 12V, which is equivalent to the original brake light switch. The other is connected to 12V and opens when the pedal is pressed.
That's how it is for me too.

Jens 16syncro wrote:

Instead of switching +12V, the normally closed contact then disconnects the ground (or vice versa)?

Yes, the opener is connected to ground when at rest and opens when the pedal is activated. This is F47/Pin 20. The other one remains connected to the brake light switch, providing 12V when the pedal is activated.
"This is also stated in the plan for the AfD's industrial initiative, and that's how I originally wired it (I think). It's all been so long ago, and thankfully I haven't had to touch that wiring since."

Greetings,
dieter

The 021AT engine is used in the Passat B4 (with a transverse engine, like the G3), while the 021GL engine is used in the Passat B5 (with a longitudinal engine).
like A4).
In the B4 module, there is a pull-up resistor (approximately 12V) in the control unit, and F47 disconnects a connection to ground.
In the B5 module, there is a pull-down resistor (connected to ground), and F47 disconnects a connection to 12V.
Since you've wired it in a B5-like configuration, you need to adjust the potential at the relevant contact.
Connect the F47 relay from 12V to ground.

Best regards, Micha.