W211 Sat Nav Switches off at night

[ChrisUK01]

Hi,

I have a 2002 W211 with Sat Nav at night the stereo switches itself off and then comes back on. It is intermittent so sometimes it will not do it other times it will happen many times in a single journey.

No body seems to know what the problem is and when I took it to Mercedes it did not happen.

I am desperate to get this sorted out does anyone have any ideas please?

Thanks

Chris.

 

[Brian WH]

It may well be going into "Night Mode" which is intended to reduce the brightness for night-time driving.

Have a look at the settings and turn the night vision setting off.

 

[ChrisUK01]

I have tried that and unfortunately that did not work.

 

[cplnoonoo]

Could be some dodgy wiring maybe coming loose but is only causing the unit to turn off and back on at night as the illumination feed is active due to the headlights being on. This feed would automatically dim the screen etc when the headlights were turned on as it would be thinking it is night time.

Any loose connections may be your answer but just to be sure...do you do any driving during the day and i take it it doesnt do it then? If so you could try manually turning on your headlights during the day and see if it turns off etc.

 

[ChrisUK01]

No it has never done it in the day in the 18 months I have had the car for.

Shall try the lights idea thanks problem is though it is intermittent.

 

[Diesel Benz]

This is a W211 car, the illumination signal should be coming as a CAN bus message and the CAN bus should be working if the device turns on and off from ignition.

Have you tried to cover the light sensor to make the car change between day and night mode repeatedly?

 

[ChrisUK01]

Where is the light sensor?

It is like the Sat Nav stereo is rebooting itself and only at night.

Yeah def a W211 the first one with all the bugs.

 

[Diesel Benz]

Where is the light sensor?

It is like the Sat Nav stereo is rebooting itself and only at night.

Yeah def a W211 the first one with all the bugs.

The light sensor is at the windscreen along with the rain sensor at the top/centre of the windscreen.

I don't think the bugs on early W211 models should be overemphasised, a few SW updates are a must, some wiring improvements for SBC brakes and it should work pretty much like the later, more reliable models. I'm not sure some of the early AGWs have to be swapped or if a SW update would be necessary. If you have issues like this night mode, I'd suggest to check at a dealer or independent workshop who has Star, if all relevant control units have their latest SW (in this case Comand and AGW specifically).

 

[cplnoonoo]

Its on the windscreen just behind where the rear view mirror is.

 

[ChrisUK01]

It has been hooked up to a Star machine and no faults was showing for the Sat Nav/Stereo

 

[cplnoonoo]

If it doesnt have any problems during the day then it must be something to do with either the time on the stereo clock or an operation of one of the systems that only takes place at night (eg when headlights are turned on etc).

Not sure how deep star would be able to diagnose like if its a loose connection somewhere im not sure if star would be able to tell that a loose connection existed.

 

[Diesel Benz]

It has been hooked up to a Star machine and no faults was showing for the Sat Nav/Stereo

So do you believe there is no fault then? Are you sure they diagnosed all relevant control units? Codes are not always present, specifically if an issue appears because of a bug in the control unit SW.

I'd check the SW release for the mentioned units, almost useless to speculate about other issues before that. Specifically if you are sure that the issues only come at night.

Is your battery and alternator good? Are you driving without headlights during daytime? Try to switch lights on, perhaps other consumers too like rear window defroster.

 

[ChrisUK01]

It has only ever happened at night and it is not as soon as the lights go on. I can be driving for 20 minutes before it does it. There does not seem to be a logical pattern behind it to say its when the lights go on or when the CD plays. The secondary battery has been replaced and it did almost stop doing it for 10 months now its back to doing it again.