STG (Engine Control Unit) on a 96 Passat (1Z) responds intermittently. Why?

Hi,

Okay, I have another question right away, now that I've been helped so well with the GRA.
With the interface I purchased from DRV in Berlin, which is presumably a high-quality product, I only get occasional access to my TCU (Transmission Control Unit) in my Passat. In a T3 that I modified with a 1Z unit from an Audi A4, I didn't experience any problems at all. However, the difference between the two models is that the Passat has a WFS (which stands for...), while the Bulli does not.
Does anyone have any idea what might be causing this?
VW mechanic Fritze mentioned earlier that it might possibly be related to the radio's GALA connection.

Regards,
Thomas.

'The 1Z devices sometimes act up. What kind of interface do you have? A hex-com adapter or a simple one? The former shouldn't cause problems, the latter more likely. Check the adapter's documentation; it might have suggestions for adjusting the settings. Otherwise, just try experimenting a bit.'

btw: what kind of error message are you actually getting?

Hello,

Kussi wrote:

Hi, Okay, I have another question right away, now that I've been helped so well with the GRA. With the interface I purchased from DRV in Berlin, which is presumably a high-quality product, I only get occasional access to my TCU (Transmission Control Unit) in my Passat. In a T3 that I modified with a 1Z unit from an Audi A4, I didn't experience any problems at all. However, the difference between the two models is that the Passat has a WFS (which stands for...), while the Bulli does not. Does anyone have any idea what might be causing this? VW mechanic Fritze mentioned earlier that it might possibly be related to the radio's GALA connection. Regards, Thomas

Well, what does DRV say about this problem? Probably nothing, because he's too busy trying to trip me up and reading my manuals.
You could have found an original Ross-Tech HEX-COM / HEX-USB interface here in the online shop for quite a bit cheaper.
If you've installed a different (non-original) radio that doesn't have a diagnostic connector, it's important to ensure that the diagnostic line isn't simply short-circuited. This is because while the radio connector might fit mechanically, the pin might have a completely different function. Of course, this only works if the radio connector in your car also has a diagnostic pin... I'm not familiar enough with the Passat to know for sure.

What specific adapter are you using, and what operating system are you running on what kind of hardware?

Best regards, Rainer.

Hi Rainer,

Yes, I'm sure I could have gotten the interface for a cheaper price, especially since they are sold for a very low price on eBay. I got one of those as well. It worked perfectly in the VW bus, but it doesn't work at all in the Passat, which is hardly surprising.
I bought the DRV product back in 2000, so everything was quite new at the time.
Therefore, it was likely one of the first models.
The hardware is an old laptop with a 486 DX4/100 processor and Windows 95, which worked perfectly fine in the VW bus.
So, overall, I think it might be related to the radio, because there are two thin wires on the plug that aren't needed, and I haven't removed them yet. I will do that during the next check and see what the laptop says.
Otherwise, the error memory is okay; I read it the last time I had access, and there were no errors stored.

That's all for now.
Regards,
Thomas.

The two thin cables are for lighting and GALA. The radio in the Passat 35i B4 cannot perform diagnostics. Diagnosis of the radio system is only possible starting with model 98, as these models were upgraded to the new generation of radios (Alpha V, Beta V, Gamma V).

I would just disconnect the GALA module. But, as sensitive as it's always portrayed, the 1Z from 96 isn't. Ours worked without any problems (if you ignore the usual issue with the 575 - the difference between intake manifold pressure and the setpoint).

Best regards, WarLord.

The hardware isn't really the most suitable for that.

Try adjusting the settings. Your problem might be solved that way.

Okay, then it probably won't be a HEX-COM adapter, but something else (like the eBay adapters, meaning it won't have its own intelligence, and if you're unlucky, it might be a slow optocoupler version).

Set a start baud rate of 240 in the VAG-COM options...

Best regards, Rainer.