ABS Failure: No Impulse Signals Detected

Hello there,

It's probably always the case that you write your first post only when you yourself have a problem, .

Okay, so I have an ABS control unit, model MK60, installed in my car. The coding is 0019970. Now, I wanted to connect my navigation system (an MFD) to it. According to the wiring diagram, I connected it to pins 8 and 10. But there are absolutely no signals coming out! The error memory is empty, and the ABS, etc., are working correctly. I then put my car on jack stands and, with the engine running and the wheels turning, I measured the signals using an oscilloscope. But there's nothing, just a clean zero line. What's going wrong here? Can you help me?
The navigation forum doesn't have any answers either, and the search function didn't help me much either.

Thank you everyone!!!
Dad.

Hi,

'Just out of curiosity, what does the navigation system need with ABS impulses? I always thought it only needed the speed pulse and the reverse gear control signal.'

Hi!

Unfortunately, I don't know the year of manufacture of the car, but at least in the newer models, active ABS sensors are installed. This means that if you disconnect the connector from the sensor and try to read the signal directly from the sensor, you won't get a value. You need to tap into the signal while the sensor is still connected. Perhaps that was the problem?

Good luck.
Dirk.

@ Marco

For example, the 'Navi Plus' or the 'MFD' systems from Audi and VW receive signals from the ABS (Anti-lock Braking System).
I believe you can also use the speed signal, but you just need to adjust it in the navigation system or multifunction display. My VDO Dayton used a speed signal as well.

'@paps - so, if it's an original navigation system with a TFT screen, then it's possible to adjust that setting.'

Regards,
arne

@paps

If you use VAG-COM to display the measuring block data (I believe it's either block 1 or 2) in the ABS control unit, and you're driving slowly (around 20 km/h), will you then see the speed for each wheel?

@m3, slow down.

Okay, on channel 1, I'm seeing the speed. On channel 2, nothing is happening. It was showing 2 km/h everywhere, even though the vehicle was stationary. I also looked at channels 11-14. Apparently, something is supposed to be counted on those, up to 65535 or something. But nothing is being counted on my device.
Is that perhaps a pulse count?

@Arne, brezelmann01

The vehicle is a Skoda Octavia Combi manufactured in 09/03, and the goal is to install the original Skoda navigation system. As far as I know, it's very similar to the VW MFD D, except for the front panel, startup logo, and lighting.
I'm not connected to the sensors because the ABS control unit (MK60) provides a dedicated output for the navigation system (pins 8 and 10).

Best regards,
Dad.

@Paps

Then the ABS sensors should be working correctly. Perhaps only a calibration is needed due to the 2 km/h difference when stationary. However, I can imagine that the ABS control unit might need to be activated to allow the signals to be output. Maybe that's the problem.

Hmm, I was also wondering if something needs to be unlocked. But the coding seems correct, at least according to my mechanic. However, maybe a value still needs to be adjusted in the settings.

I really don't know what to do anymore, .

Best regards,
Dad.

Can anyone really help me anymore?

Best regards,
Dad.

Okay, I tried using my VAG-COM again today. It's not possible to adjust individual channels; it just says 'Error, not available.'
Okay, so I reconnected my oscilloscope. I connected it to the rear sensors. Then I made the wheel spin, and I got a nice sine wave. Then I checked pins 8 and 10 of the control unit again, and still nothing. Tomorrow, I'll start by removing the navigation system. I don't want that thing to be broken and be pulling the signal down to ground. Then we'll see. It would be funny if that was the problem...

In this spirit.
Dad.

Hi,

Alternatively, there might be a speed signal available at the car radio that you could tap into, due to the speed-dependent volume control. As far as I know, most navigation systems (VDODAYTON definitely does) self-calibrate based on the pulse rate per speed and the polarity for reverse gear.

Best regards, KAi.

I just wanted it to be the same as it is from the factory. I'll only look at the Gala signal if I really can't figure it out. It looks like it's going to be a long day tomorrow...

Best regards,
Dad.