Data Bus Error 01336: Single-Wire Solution

What does this error mean?

Which car? Engine code? Year of manufacture?

Hi,

Normally, the control units communicate with each other via a CAN bus using two wires, and a differential transmission takes place.
http://www.gsi.de/informationen/wti/dvee/exp_kontrol/bus_can.html

In cases of intermittent reversion to "single-wire" operation, such as with your car, a possible cause could be a break or short circuit in one of the wires.
-> Intermittent connection or chafed cable.

Best regards, Rainer.

Good evening.

I would like to test my Comfort CAN bus because I am unable to clear the following error codes.

Car: Skoda Octavia 4x4 1.8T

VAG-COM Version: 409.0

Control unit part number: 1U0 920 841 H.
Component or version: KOMBI+SPEED SENSOR VDO V07
Software coding: 31112
Workshop Code: WSC 31480.
additional info: TMBKL21U728567906 SKZ7Z0A133175906
Sure, here is the translation of the text from German to English:

'1 error found:'
01336 - Corporate Data Bus Comfort.
80-00 - in single-wire operation.

respectively / or rather / that is to say

VAG-COM Version: 409.0

Control unit part number: 6N0 909 901.
Component or Version: Gateway K<->CAN 0001.
Software coding: 00006
Workshop Code: WSC 31480.
Sure, here is the translation of the text from German to English:

'1 error found:'
01336 - Corporate Data Bus Comfort.
80-00 - in single-wire operation.


The original thread was about this:
/viewtopic.php?p=64860#64860


I have a 2-channel oscilloscope (analog/mixed signal) up to 30 MHz and various multimeters available.

http://www.gsi.de/informationen/wti/dvee/exp_kontrol/bus_can.html

I understand the basic principle of how it works, to some extent.

Is there a VW repair manual available for troubleshooting?

Otherwise, I would measure both wires against ground and use the oscilloscope to examine the differential signal, i.e., H relative to ground and L relative to ground.

Given that the entire system is a bus, in my opinion, I can only diagnose a break by measuring the resistance between the H or L terminal at the end of the bus and the beginning of the bus using an ohmmeter.

Is that correct?

The CAN bus must always be closed and is terminated with a resistor (120 ohms) at each end. It somehow reminds me of the good old BNC network cabling.

One end of the CAN bus connects to my diagnostic connector. However, I couldn't detect any resistance there. I'll need to study the wiring diagrams.

Hello,

'But everything is working perfectly fine in the car, right?'

I suspect a faulty gateway control unit, which essentially 'manages' the CAN bus. Especially when using non-original VW diagnostic tools to access the CAN bus, it can sometimes lead to failures. The CAN components in the control units (particularly the gateway) are extremely sensitive to voltage spikes and static electricity on the CAN lines.

Is that the new Octavia, or is it still the 'old' model?

You can only check if there is signal activity on the CAN lines. If you measure approximately 2.5V DC on a CAN line, then it is defective.

Everything seems to be fine with the car, except that the ESP warning light is on and sometimes flickers. The car is from April 2002, which means it's an Octavia I facelift model.

see thread.
/viewtopic.php?t=9625&highlight=4x4

I thought the error was gone, but yesterday it flickered again .

After that, I checked the most important standard operating procedures.



DO I need to measure the CAN lines against ground, or should I measure the 2.5V directly between CAN-H and CAN-L?

Hello,

You need to measure the CAN lines against ground.

I'm reviving this old thread.

I'm having a problem with the CAN bus in my Golf. The CAN-Low line is directly connected to ground when the ignition is off.
Is this how it's supposed to be? Can I take measurements with the ignition on?

Hello,

Which CAN bus are you measuring?
Do you have any error codes stored?

How did you measure?

You shouldn't have any short circuits to ground, regardless of whether the Kl15 is active or not.
The CAN_Low signal on the comfort CAN should be at 0V, but it should not have a direct connection to ground.

Best regards, Jochen.

p.s.:

Sure, here's the translation:

'Perhaps a few additions to what was written above:'

Single-wire operation is only possible with the Comfort-CAN, as the data transfer rate is limited to a maximum of 250 kBd in single-wire mode.


A high-speed CAN bus (e.g., the engine CAN) is typically terminated with approximately 60 ohms in total.
This means that, depending on the bus configuration, either two ~120 Ohm resistors are connected at the ends, or a ~60 Ohm resistor is connected at the star point.
You cannot measure a 120 Ohm termination resistor on a properly configured CAN bus; you will only measure the total resistance, which is approximately 60 Ohms.

A low-speed CAN (Comfort-CAN) in a passenger car is significantly slower, e.g., 125 kBd or less, and may have different voltage levels. Therefore, it does not necessarily need to be terminated.

Thank you.

I would have been surprised if that was okay, given that the CAN-Low line is connected to ground.

I systematically disconnected all devices connected to the Comfort-CAN, one by one, and repeatedly took measurements.
After I had disassembled half of the A-panel, I realized that the glove compartment was pressing a cable from the TMC box against the metal .

Bugs fixed and I am happy .

"Edit: I measured the continuity to ground on pins 8 and 9 of the microcontroller."

I found the same error today in my Octavia 2003. It was exactly as described above, logged in the CAN gateway and the instrument cluster. Now the troubleshooting begins.

Do you know if the radio is integrated into the comfort CAN bus? I'm not sure if I have the diagnostic cable properly connected (I don't remember), and my aftermarket radio is giving me problems.

Everything is working perfectly for me, so I'm wondering if I should even bother troubleshooting.


EDIT: The radio is not related to the diagnostic issue, so it can't be the cause. As far as I can tell, in the Octavia 1, the CAN gateway is integrated into the instrument cluster, which would be problematic if the gateway is faulty. The Skoda repair manual states that you should first replace the gateway and then see if the error reappears. If it does, you should check the wiring. So far, I haven't been able to find any damage.

Which control units are definitely connected to the comfort CAN bus in the Golf IV generation?


I'm certain that all four door control units, the radio, and the instrument cluster are included. What else is included?


And: Does anyone have wiring diagrams for the Komfort-CAN? I can't find anything about it.

Cause of the error found by chance.

The cable routing in the front doors, at least on the right side, has a protective edge and is thickly padded with foam.

On the left side, this wasn't the case - the cable was frayed and resting on the body. I re-insulated it, added a protective strip around the sharp metal edge, and stuffed a foam cube in there, just like on the other side - the problem is solved.

It would be interesting to know if this was "forgotten" in all Octavia models.

At least the error is gone, and most importantly, the CAN gateway (and therefore the speedometer!) is working properly.

Okay, then thank you for the feedback!