ManiacGT

So I'm sat in the car waiting for a shop to open. Listening to music I turn off the engine and pre ignition just leaving the COMAND screen running. As usual the main binnacle display goes dark after a few seconds.

After a few minutes I reclined the seat to be comfortable and as I did that the car woke up and the binnacle showed the usual information. Thinking only hm unusual I ignored it. That is, until it started doing this;

Glyn M Ruck

You woke up one of the CAN networks.

ManiacGT

I figured the seat movement woke something up. The question is why not just power down again or stay powered on. The shutdown/power up cycle didn't stop until I opened the car door. I was concerned that the sidelight lamp was actually showing the external lights coming on and off while it was doing it.

Merlin1

At least the car didn't do any more miles - that would have been interesting!!

angeloxnet

hrmm maybe the light sensor was detecting changes in light and turning on the park lights? a

digitallust_aus

how do you get the km/h in the top left corner?

jolt8631

That's the default in the UK market.

DBOC205

That's the first thing I noticed too... I've never seen that before on mine either. Who else gets this config?

rustycruiser

It's available in US cars as well. It is available via the Additional Speedometer sub menu. It is always inverse to the main speedometer setting. So if you Aussies have your car set to kilometers, it will only allow you to display MPH.

Glyn M Ruck

All the CAN networks have a duty cycle after which they will hibernate again to save power. They usually wake up when you unlock the drivers door as an example. If you then don't get into the car within a preset time they will lock the door & go back into hibernation. I placed an operational paper from Benz to the W203 Wiki if you are interested in their basic operation with the SAM's, cluster etc. They are of course steadily becoming more sophisticated.

You wanted to move the seat so the CAN network had to wake up to perform the operation. Saves miles of hard wiring. Every module in the car operates via one of the CAN networks.

ManiacGT

I can understand that Glyn, but as per my video, why would the car then power up and power down then power up and power down in a continuous cycle? If you watch the entire video you'll see what I mean. I had moved the seat, which woke up the car, but then did nothing further and for several minutes, until I opened the car door, the dash powered up then down then up then down etc.

Glyn M Ruck

Yes I noticed that in your video. Might be a microprocessor EPROM programming glitch. Watch it. Newer software might become available for SAM's etc. Try & compare with another car & see if you can replicate conditions. The hibernation trigger might be a little too sensitive.

This is why new models need to be dealer serviced. They will always connect to a Star & do software updates as they become available. You would be surprised at how many there are early in a model's life cycle.