W210 stopped & wont start

[NotAnumber]

Good memories of a W210 for several years before I eventually moved onto a S212 but I got a call today from an old freind who bought his W210 at the same time as me but sensibly hung onto it. It's been problem free for years but the other day the engine cut out whilst it was idling (he was pumping the tyres up at the time). When he went to restart there were the expected dashboard lights but no noise from the starter.

He first suspected the battery may have suddenly failed as it was a few years old but a new battery made no difference. He is 40 miles away and ive been trying to help him diagnose it over the phone and the guy doesnt use a computer so Im having to look things up for him..

Does anyone have any pointers please ?

To recap so far its a W210 E320 cdi.
The car is used regularly and has been problem free.
It cut out whilst idling (which it has never done before)
The starter motor does not turn, click or make a sound. No previous issues expereinced with the starter
Low voltage was suspected but neither a charge nor a new battery has made a difference
Has checked all the fuses he can find (and was not doing anything at the time likely to have caused a fuse to blow)
Has tried the spare key and had also tried changed the batery on the first key.


Im wondering if the power distribution ECU could be a likely culprit.
Are they known for sudden failure and adoes anyone know if a 2nd hand one be swapped in or does it need to be dealer coded to the vehicle ?

Any other thoughts as to what it might be please ?

 

[ChipChop]

Quick look online for no crank on a w210 brings up possible K40 relay fault or perhaps an EIS issue.

 

[mersum1es]

Measure you are having healthy 12 voltage in engine bay (no troubles in battery leads, feed cable under drivers seat or ground strap behind transmission). Try direct 12V feed to starter (though faulty starter should not kill the engine). As above K40 is common to fail.