Windscreen Washer S211 E320

[E240estate]

Hi, odd problem with the windscreen washer.
Fluid full, jets clear.
When I turn on the ignition, washer works fine, ie I hold the button down and the spray is strong and continuous.
When I start the engine, a press of the button only gives about half a second of water and it switches off.
It will repeat this five times then refuses to work at all, until I stop and switch off and restart.
At that point it works fine again with the ignition on, then start engine then five short bursts then nothing.
Pretty certain it's an electronic issue with the pump switching itself off or controlled by the computer, and not a physical problem like leaking or lack of pressure.
Any help appreciated

 

[Petrol Pete]

Not sure about your car but on some MB the washers will not operate under certain conditions , bonnet open , door open etc . on some convertibles if the roof is down the spray only happens on the downward stroke of the wiper blades. Headlamp wash not working if the lights are off etc.

Now . all of this has to be controlled by something my guess is the fault lies there ...but where . ? Might be worth getting the codes read .

 

[mersum1es]

Do you have headlight washers? Do they operate every 5th windscreen wash? Just a thought... codes would tell if there is such short circuit which put system to fail safe... though never heard this kind of malfunction earlier.