Comfort Bus Emergency, Door Control Unit or Lock?

Hello,

I've been reading here for a long time, and I have to say that I really appreciate this forum!


Now, I'm having a problem with my KomforElektrik system, and I need some help making a decision, but so far, no one has been able to really assist me.

The problem is, my door would sometimes just lock itself. I know about the locking mechanism, etc., but I don't think it's a problem with the locking mechanism itself.
Otherwise, the function is perfect; it can be locked in "safe" mode, and it switches between "safe" and "unsafe" modes even when locked.

I have the following errors in the memory:

Engine Control Unit Part Number: 1J0 959 799 L

Component and/or Version: 0W Central-SG Comfort.0002

Software Coding: 04097

Workshop code: WSC 00000

Zusätzliche Information: 1U4959801A 0W Tõrsteuerger. FS0022

Zusätzliche Information: 1U4959802A 0W Tõrsteuerger. BF0001

Zusätzliche Information: 1U0959811A 0W Tõrsteuerger. HL0022

Zusätzliche Information: 1U0959812A 0W Tõrsteuerger. HR0022

2 errors found:

01329 - Data bus, comfort functions in emergency mode.

35-00 - -

00931 - Rear right central locking latching unit (F223)

54-00 - Incorrect equipment.

Sometimes, there can be sporadic errors such as "HR closing unit failure" or "implausible signal."

I have made the following observations:

1) The signals from the door lock in MWB 7 are plausible.

2) The bus emergency mode only disappears when you disconnect the TSG HR.
MWB 12 also states that the bus is okay ("i.O." - in Ordnung) as soon as the TSG HR is no longer connected.
If the TSG HR device is inserted, whether the lock is engaged or not, the bus immediately goes into emergency mode.
The "incorrect configuration" error can be deleted, but it reappears after a while.

Here are the questions that come to mind:

1) Is it generally the case that the TSG (Technical Safety Group) puts the bus into emergency mode if connected actuators are not functioning correctly? Because the communication on the bus itself is not actually impaired?

2) How can the "Incorrect Configuration" error occur (which could indicate incorrect wiring), even when all signals from the lock appear to be valid?

3) If the lock exhibits occasional malfunctions, the TSG (presumably a diagnostic system) can only detect them once they have occurred. So why does it immediately switch the bus into emergency mode as soon as it is connected?

4) Since there are specific error messages for bus interruptions and short circuits, can I exclude those possibilities?

Can I assume that the TSG itself is the source of the problem, based on the symptoms? The wiring and connectors look okay to me. Interruptions or short circuits in the lock or in the wiring to the lock should not affect the actual communication on the bus, and therefore should not trigger a bus error mode.
Wiring defects in the bus connection to the TSG should generate bus error messages such as "short circuit after..." or "single-wire operation." However, these error messages are not present.

If the answer to my question 1 is yes, then why does the TSG (Transmission Control System) put the bus into emergency mode BEFORE it detects any errors in the locking mechanism?

Regards,
Malte.

...because the CAN interface in the TSG is probably defective. Based on your description, nothing else seems to be broken.

CAN-Bus fail-safe mode = single-wire operation.

Has the TSG (Type Approval Mark) ever been replaced? Incorrect equipment, huh? Are you sure the TSG is actually the one for the right rear?

Hi Thomas,

"When I pull the TSG (throttle shaft guide) out, the bus emergency brake fault disappears. The error message 'incorrect equipment' clearly indicates that it's an HR (high-range) system."
However, I didn't experience any issues with the wired connection, but only with the emergency mode and the other two modes.

I don't know if the TSG has ever been replaced before.

Regards,
Malte.

Hello Malte,

Just replace the TSG unit, and that should fix it; it's definitely defective.

I'd be interested in some information about the vehicle. Generally, I'd also initially lean towards the TSG HR.

Could you please provide some details, such as the build/model year and, most importantly, the specific vehicle?

I would initially suspect the Octavia. It's also interesting to see the differences between the firmware versions of the door control units. The index/color code of the control unit in the rear right door seems okay, so I would first try to resolve the emergency error. If that works, the corresponding error (incorrect equipment) might also disappear. Please carefully examine the wiring, as that is most likely where the problem lies, and everything else is probably just a consequence.

Hello,

It's an Octavia, manufactured in May 1998. If the weather is better, I'll take another look at the wiring.
The fact that the bus is going into emergency mode suggests that the TSG HR (presumably a system or component) is not having proper communication. However, the bus connection to that component is neither interrupted nor briefly disconnected, otherwise we would see corresponding error messages.

Or, a question that remains unanswered for me is whether the TSG (Traffic Signalling System) always switches the bus into emergency mode if its actuators are defective (which, in my opinion, would be ridiculous, but one shouldn't rule anything out). So, could everything potentially be controlled from the locking system?

Here's the translation:

"How can you determine the firmware version of the control units? Which TSGs (Technical Service Bulletins) refer to newer firmware?"

Regards,
Malte.

Hello,

I replaced the wiring harness in the door. Everything is fine now, and after 5 days, there are still no intermittent issues with the door lock, and the door isn't opening on its own anymore.

"There was actually a broken CAN bus line in the wiring harness. I had become so fixated on the idea that I would have to see the 'single-wire mode' message that I missed it."

Regards,
Malte.