Crank and stalls
I have this c300 car will crank and run for 1 second and then stalls . when this happens the instrument cluster goes dead and you loss circuit 15 for relays in front same box . cycle the key and every thing starts working again in tell you crank it again . Any ideas thanks in advance
Have you performed a complete scan for codes can you connect to ecm?
no codes any modules
Do you have tool to check transponder in key and what type of key do you have ie aftermarket or factory
Yes I have checked the key and it is oem
Check the battery!
Does it have fuses or breakers? If breakers... maybe weak breaker feeding the 15 circuit. If 15 circuit feeds the run relay possibly weak relay...? I don't work on Mercedes much. Recently had an older jeep that had similar issue... it would run for awhile intermittently, then @ times would experience these symptoms. No faults. Just die like no signal. Finally caught it running and messed with…
Does not use breakers . And relays have been swapped
You got any scan or scope data to share?
Scope what ? Scan data all looks good no codes the only scan data thats weird is in the electronic ignition switch it shows 5 pids for circuit 15 . With key on all are active when you crank pids go in active
Got a wiring schematic I can see?
here are some more
I would check the Front prefuse box.
That was my thought but my friend at mb said it could not be that do to losing circuit 15