ECU Coding: Where to Find the Code Table?

Vehicle: Passat VR6 syncro.
ABS Block: 3A0 907 379 D

Okay, I've now obtained an ABS control unit that fits and is recognized by the VAG-Com system. However, I can't seem to code it: Using the Golf III codes (03604 and 3704), I only get a 'Control Module Incorrectly Coded' error in the diagnostic memory, and the Passat code (04505) isn't accepted at all.

'With the diagnostic tool, I'm only getting a code for a faulty ABS sensor in the error memory, but I'm not even sure if that sensor is working properly.'

Can someone tell me how to code the module or control unit? Or do you have a table that explains what all the settings mean? Or can you tell me if using '00000' will work without any problems?

Best regards, WarLord.

lappen wrote:

Take a look at openobd....... Vw->Passat(3B)->Brake electronics. Maybe it will help

.

Since he has a Passat 3A, that won't be much help to him...

The problem is that control units with stored error codes typically cannot be coded, and a coding of "00000" is not permitted.

'I can already code the control unit with the sensor error to 03604 and 03704, but then I get the message 'Control Module Incorrectly Coded.' I can't code 04505 at all, neither from 00000, nor from 03604, nor from 03704. I've already tried coding 04604, but it accepts that too, but then displays the message 'Control Module Incorrectly Coded' again.'

Best regards, WarLord.

Could you please provide more specific details?
- Year of manufacture of the car,
- Has the control unit been replaced (with the same one), or has it been upgraded to include ABS?
- Is the part number shown at the top when logging into the ABS module using VAGCOM?

Okay.

The vehicle's manufacturing year is 1995 (likely between August and October).

The control unit, or the entire ABS module, has been replaced. The original module contained both ABS and EDL (Electronic Differential Lock) functions. The replacement module only has ABS. This was necessary because the contacts on the original module were corroded due to water ingress (caused by a missing sealing grommet and a broken connector housing).

The number above appears when logging in with VAG-Com.

Best regards, WarLord.

Well, that's not going to happen today or tomorrow.
The system installed in the Passat is not compatible with the control unit with index D, and I doubt that a similar unit was ever installed before; it was probably more likely a unit with index B. The control unit with index D has now been replaced by the 3A0 907 375 and is only used in the Golf/Cabrio and Vento, but never in the Passat, because the Passat uses either a Teves or an ITT brake hydraulic system.

The system installed in the Passat is not compatible with the control unit with index D, and I doubt that a similar one was installed before; it was probably more likely one with index B.

I don't understand why the system is reporting a code 00000 and displaying an ABS sensor error, while another code indicates 'Control Module Incorrectly Coded.' What I also don't understand is why the system installed in the Passat is supposedly incompatible with the engine block or the control unit. What does the control unit even know about the rest of the system?

Incidentally, there was a control unit with index A installed previously.

Where can I get coding data along with the corresponding vehicles?

Best regards, WarLord.

The problem probably lies...

a) Regarding the control and potentially also the allocation of cables from the control unit (STG) to the hydraulic system.
b) Communication to the engine control unit (ECU).
c) From certain production years onwards, the engine control unit (ECU) changed, and there were also modified sensors ('T').
d) other sensors between the Golf and the Passat.

By the way, the 379 A is a replacement for the 379 C, not the 379 D, and it's for vehicles manufactured from 1996 onwards (VIN T 000 001 and above) - check your vehicle registration document.

Differences (now referring to vehicles starting with the letter 'T'):

The hydraulic unit is available with or without Electronic Stability Control (ESC), and there is a dedicated Transmission Control Unit (TCU) for it.
You cannot connect a standalone ABS module to an ABS/EDS block.

The code 0000 may not function correctly and is designed by VW as a default delivery code with a 'permanent' error message, so that the warning light illuminates and no one can 'forget' to code the control unit 'correctly'!

A: That can't be right, it's just a part.
B: There is none available, it's an autonomous system (unless we're talking about the K-line, which I don't think we are).
C: Okay, I'll let that slide, especially regarding the sensors. But why aren't all of them displayed as faulty, but only the one in the front right or left?
D: Maybe.

I completely replaced the entire hydraulic unit with the control module, not just the control module itself. This means the block is ABS and the control module is also ABS, and the whole assembly came from a Golf III manufactured in 1997.

I have the ABS system, where the control unit is bolted to the engine block.

Best regards, WarLord.

Okay, what does your VIN (Vehicle Identification Number) say? It starts with 3AZ????.

a) good.
b) Hmm, no connection from the ABS to the engine? I'll have to check that.

3AZTE000407

The wiring diagram does not show a connection to the engine control unit, and the engine control unit also does not report any ABS fault.

I know that control unit A is not being replaced by D (since it doesn't have an EDS), but the EDS thing isn't relevant anyway, because I don't even want that feature.

Best regards, WarLord.

Okay, so that means you've now got an engine block and a transmission from a 1997 Golf in a 1996 Passat.

The fact is, the sensors are definitely different.
I also don't believe that the Golf has the exact same pin configuration for its connectors as the Passat.

But I'll take another look at everything on Monday.

'I don't have any problems with the sensors themselves, but I don't understand why only one sensor is showing up in the error memory (with the code 00000, which I'm leaving as is for now) and not all four. Another question I have: ABS sensors are being offered on eBay. These are supposedly compatible with all Golf III models, Golf IV models, Passat models from 1994-1997, and others. This would suggest that they are the same, which would support my suspicion that the front ABS sensor is defective (I'll measure the sensors to confirm this).'

The pin configuration should actually be the same, but I'll double-check the wiring diagrams again.

Best regards, WarLord.

Did you flip any pins, or did you just unplug, remove the module, insert a different module, and plug it back in?

Okay, so I looked at it today and I think I found the error.
Specifically, they installed a coding bridge in the wiring harness.

On the Passat, the connection from pin 15 to pin 21 is located on the control unit (STG) connector.
AND FOR GOLF:

from pin 6 to pin 22.

All other contacts are configured identically.
Reverse the polarity of the two contacts, and it should then be able to code properly for golf.
It might then report faulty sensors (because they are likely different in 99% of cases), but perhaps it will work even with those, and the part number is just different due to variations in cable lengths, shapes, etc.

Hey, that's a dumb question, but what's the point of using different control units (for Golf and Passat) for just ABS, but using the same control units for ABS with EDS?

Best regards, WarLord.