Hougaard

My 2002 W210 M112 has a misfire on cylinder 3 which seems to be caused by a lack of pulse.

When starting all is good, but after a few seconds, cylinder 3 shuts off. I have tried with a test light to the injector plug, it blinks as it should for a few seconds, but then goes off. I have also tried to connect a fuel injector to the plug, clicks fine for a few seconds, then shuts down.

Connection to ECU is checked and good.

DTCs found:
P0203 (Y62y3 cylinder 3 fuel injector) - MIL on & current
P0300-80 (Misfire cylinder 4) - MIL on & stored & current
P0304-82 (Misfire cylinder 4) - MIL on & current
P0303-83 (misfire cylinder 3) - MIL on & stored & current
P0303-67 (Misfire cylinder 3) - current
P0304-69 (Misfire cylinder 4) - current

All spark plugs and coils were replaced about 2,000 km ago.

I hope it doesn't require a new ECU.

Plutoe

if its not the injector than its the ECU----loads of used ones on ebay simply check MB EPC for all the applicable ECU for your VIN

Hougaard

I suspected that.

However, I believe ECU swapping will not work - only a new virgin from MB dealer will. Do you have any experience to suggest it would be possible to simply swap ECU with same part number?

Plutoe

you can believe what you want,but my experience says it does work.However you still dont know if your ECU has an electronic or software issue and you have never posted a short test suggesting and ECU issue.I dont know how to determine that other than flash your ECU---does the ECU accept the flash and solves your issue or the flash is not accepted for what ever reason
All my comments are based on my working knowledge of the MB DAS and XDOS diagnostic systems. If you dont have either of those tools and or experience then sell the car or go to someone who has the tools and experience