A Class no power on ignition
 

Hi There,

I wonder if any of you can help.
I have an A Class (w176) A180 CDI (2013) which had an accident front left but nothing major. I have tried to start the engine but nothing happens when turning the ignition key even though I do have lights on the dashboard.
I know there is a prefuse to cut power from the battery in case of accident but I am not sure if this is the cause. Is there a way I can test this fuse? Does anybody knows where is it located and what colour this fuse is? Also is there anything else I should check that could be causing this problem?

Thanks in advance for your help!!! http://www.aclassclub.co.uk/forum/im...face_smile.png

I spent a couple of hours again and can give more details.
Pyro fuse in the battery is ok. Both wire from the battery negative and positive have continuity when tested.
Alternator - has also power from the battery cable.
Starter - both thick wires are ok. I have power on the positive wire and negative is also earthed. When I checked the thin wire that activates the starter motor, there is no live. Having a direct cable to the battery does kick start the starter motor.
Tracing this wire, it comes from the ECU.
On the dashboard I have only basic lights but turning the ignition key does not change anything else.
Do you think it is the ECU that cut power to these elements following the accident? What needs to be done if that is the case or is there something else I need to check?

Many thanks

Just an update on this issue if it can help someone.
The problem was narrowed down to the Electronic Steering Lock. The car had been jump started with the key inserted in EIS and damaged the handshake between EIS and ESL.
I was not able to recode a second hand ESL, and getting a new one could only be done by MB which would go up to a thousand pounds, very expensive. So I was able to get an emulator and a garage here in London were very helpful in getting the emulator recoded to the EIS so it could get a successful handshake. The engine now starts, I have all lights on dashboard and everything is working as it should be. London Code were very knowledgeable and specialises in MB so they know what they do. It is rather strange that a failure to the ESL could cause such a lack of power in the car as I wasn't even able to power the windows or the radio but there you are. Thats Mercedes for you!!!

Problem solved and hope this will help someone with the same problem.

Mercedes tech documents I've read specifically call for the key fob to be removed from the ignition when connecting jumper cables or installing a replacement battery. With key fob inserted the circuits are energized and susceptible to voltage spikes; you may get lucky and suffer no consequences, or you may have several fuses blow, or you may have one or more modules destroyed.

Glad you were able to work around it and here's hoping your experience will serve as a lesson for others.

Mercedes A180 W176 1.5 diesel AMG line
 

Mercedes A180 W176 1.5 diesel AMG line