Dead c200 w203 2006

[alphagemini]

I have a nice c200 w203 2006 with only 75k miles. Love the thing. But it is dead. I've checked all the relays and fuses, replaced the SAM to no effect. New battery. My OBD scanner will fire up but then shows 'unable to connect'. When I turn on the ignition the lights show OK. All the electrics work. Any bright ideas please. I can't get a specialist mobile MB guy to visit here in Folkestone.

 

[Petrol Pete]

A bit more detail please . Broken down on the way home ?

Was it running and driving or in storage before the fault arrived ? Had work done ? Been in a bump ?

 

[alphagemini]

A bit more detail please . Broken down on the way home ?

Was it running and driving or in storage before the fault arrived ? Had work done ? Been in a bump ?

I had just changed a reversing light bulb. I had also replaced the light switch module because the mirror folding function was dodgy.
It was parked on my drive. Nobump. Thanks for your response

 

[Petrol Pete]

OK , to be clear . You went from a running and driving car with no fault codes to a 'no crank , no start' after changing a reversing lamp and a 'light switch' module ' ?

 

[alphagemini]

Yes. I've checked all the relays and fuses and even tried a used SAM with the same part no. but no difference. The OBD port has power and fires up my reader but then it says no communication. All the electrics work, radio, lights, door locking, including remote. The headlights don't dim when I turn the key to crank. The battery is new. Thanks for your interest, I'm at a complete loss.

 

[markjay]

Did you consider fitting back the faulty parts?

Unless you've managed to short-circuit something (or blow a fuse) while doing the work, then removing the newly-fitted parts might resolve the issue.

 

[alphagemini]

Did you consider fitting back the faulty parts?

Unless you've managed to short-circuit something (or blow a fuse) while doing the work, then removing the newly-fitted parts might resolve the issue.

I've disconnected the new light switch. The Light bulb is the same onen with corrosion removed.

 

[alphagemini]

I have found that when I turn the iignition key to crank the syarter relay on the SAM doesn't activate.
Is this an EIS problem?