Odd E350CDI MOT test experience.
Discussion
Have just had my 25,000 mile 2011 E350 Sport coupe for it's MOT test. Was absolutely astonished to be told it had failed on the headlamp washer system being inoperative.
Upon returning home I decided to investigate the 'fault'.
Whilst I have never taken great heed of this system's idiosyncrasies. This experience has now acquainted me with them.
After a spot of googling we established that with the engine and the headlamps switched on and after the tenth press of the screenwash button, out popped the headlamp washers spraying the headlamps liberally with screenwash.
I immediately took this up with the MOT tester who eventually stated that neither he nor the VOSA tester examiner were familiar with this systems operating procedure.
Upon returning my vehicle to the test centre and a quick spray of the headlamps after following the above procedure, I was promptly issued with my test certificate.
The odd thing was the same tester has tested my vehicle on the last three occasions and saw fit to pass it first time on the previous two!
Has anyone had a similar experience?
Upon returning home I decided to investigate the 'fault'.
Whilst I have never taken great heed of this system's idiosyncrasies. This experience has now acquainted me with them.
After a spot of googling we established that with the engine and the headlamps switched on and after the tenth press of the screenwash button, out popped the headlamp washers spraying the headlamps liberally with screenwash.
I immediately took this up with the MOT tester who eventually stated that neither he nor the VOSA tester examiner were familiar with this systems operating procedure.
Upon returning my vehicle to the test centre and a quick spray of the headlamps after following the above procedure, I was promptly issued with my test certificate.
The odd thing was the same tester has tested my vehicle on the last three occasions and saw fit to pass it first time on the previous two!
Has anyone had a similar experience?
Edited by disad-vantage-d on Monday 21st March 20:39
Mr E said:
xjay1337 said:
That must be the first time they ever check washer systems. Never heard of a fail before.
Bit anal if you ask me.
Mandatory for modern headlights (along with the levelling system). Bit anal if you ask me.
Pretty sure mine don't behave like that but I'll check
Ironically last year the same tester failed my wife's Polo on a headlamp bulb. The bulb was working but had a fngerprint on it. I was informed that it affects the spread of the beam. You live and learn...
Edited by disad-vantage-d on Monday 21st March 20:40
disad-vantage-d said:
Mr E said:
xjay1337 said:
That must be the first time they ever check washer systems. Never heard of a fail before.
Bit anal if you ask me.
Mandatory for modern headlights (along with the levelling system). Bit anal if you ask me.
Pretty sure mine don't behave like that but I'll check
Ironically last year the same tester failed my wife's Polo on a headlamp bulb. The bulb was working but had a fngerprint on it. I was informed that it affects the spread of the beam. You live and learn...
Edited by disad-vantage-d on Monday 21st March 20:40
The rule is "if fitted they must work".
donkmeister said:
On my 2004 E500 it happens every 10th squirt, plus there is an additional button near the lighting controls to squirt at will. Have they removed the additional button on newer variants?
Vot, are you saying zat zee car lets you, a mere humanoid, control something?
. Madness. Votever next 
DKL said:
Mine does James so it must be that they trust the users of newer cars less than those of older ones. Makes sense really!

Probably. Or I can't see it, which would be your fault. I do remember the Saab ran the light washers if the lights were on, and as a result went through pints of washer fluid.
donkmeister said:
On my 2004 E500 it happens every 10th squirt, plus there is an additional button near the lighting controls to squirt at will. Have they removed the additional button on newer variants?
Yes they have - my 2006 CLS has the 10th wash / manual operation button, my wife's 2009 E class has the same light switch (and is mechanically identical) but the manual button has disappeared. xjay1337 said:
disad-vantage-d said:
Mr E said:
xjay1337 said:
That must be the first time they ever check washer systems. Never heard of a fail before.
Bit anal if you ask me.
Mandatory for modern headlights (along with the levelling system). Bit anal if you ask me.
Pretty sure mine don't behave like that but I'll check
Ironically last year the same tester failed my wife's Polo on a headlamp bulb. The bulb was working but had a fngerprint on it. I was informed that it affects the spread of the beam. You live and learn...
Edited by disad-vantage-d on Monday 21st March 20:40
The rule is "if fitted they must work".
For instance reversing lights aren't tested, if it hasn't xenons the headlamp washer system not tested.
Incidentally if lower power xenons (Audi A1) then they don't need a washer system.
Edited by PositronicRay on Monday 28th March 18:18
PositronicRay said:
No such rule
For instance reversing lights aren't tested, if it hasn't xenons the headlamp washer system not tested.
Incidentally if lower power xenons (Audi A1) then they don't need a washer system.
We (ukmkivs.net) forum have spoken to VOSA about thisFor instance reversing lights aren't tested, if it hasn't xenons the headlamp washer system not tested.
Incidentally if lower power xenons (Audi A1) then they don't need a washer system.
Edited by PositronicRay on Monday 28th March 18:18
As a lot of people were retrofitting OEM Xenon lights without retrofitting the washer system (for obvious complexity reasons).
Officially if less than 2000 Lumens the washer units are not needed but if over 2000 they are, however MOT test stations can't test lumens, so must assume they are lower than 2000 units.
If a headlight washing system is fitted it must work.
That was direct from Vosa about 3 years ago? May have changed now though

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