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I got little problem with my 2011 E350 4matic engine m272. The check engine light come and the vehicle just can not start, no crank. I check the fuse box first and find the fuse #23 (engine electronics) blown. Fuel pump is working, I can hear the sound when turn the key to ON.
I have my OBDII scan (image attached). I start with bank 1 intake and exhaust adjuster also the position sensor. I unplug them all, replace new fuse, open the door, and the fuse blown right the way. I also try unplug the fuel pump at back seat. fuse keep blown after open the door.
I really need some advise on this situation, any clue so I can just try.
In the meantime get a copy of WIS/EPC off eBay... you'll need it. We can pull the engine wiring diagram and start tracing fuse circuit #23. Essentially try to isolate, as much as possible, down to the module which is drawing too much current.
I see engine electronics, which could be more than just the ECU and fuel pump/s on a 20A circuit on the fuse layout diagram.
When does the fuse blow, as soon as you put it in or when you turn the key to a specific position? You say the fuse still blew after disconnecting the fuel pump? I would imagine the draw is greater due to the pump/s than the ECU.
See what happens when you leave the fuel pump/s connected and disconnect the ECU on top of the intake manifold. It certainly won't crank, but again depending on when the fuse blows it might be insightful.
Also make sure you using the correct size and a quality fuse.
In the meantime get a copy of WIS/EPC off eBay... you'll need it. We can pull the engine wiring diagram and start tracing fuse circuit #23. Essentially try to isolate, as much as possible, down to the module which is drawing too much current.
I see engine electronics, which could be more than just the ECU and fuel pump/s on a 20A circuit on the fuse layout diagram.
When does the fuse blow, as soon as you put it in or when you turn the key to a specific position? You say the fuse still blew after disconnecting the fuel pump? I would imagine the draw is greater due to the pump/s than the ECU.
See what happens when you leave the fuel pump/s connected and disconnect the ECU on top of the intake manifold. It certainly won't crank, but again depending on when the fuse blows it might be insightful.
Also make sure you using the correct size and a quality fuse.
The car stop yesterday. This morning I try new fuse for first time it crank once and no start, fuse blow. After that every time I put new fuse in, soon I open the door, no key in the ignition, fuse blow.
I got atc fuse 20amp from autozone so I believe it not bad fuse.
The way fuse blows when waking up the car with ignition still off, make this short circuit part of the waking up power sequence carried by sleepless F-SAM.
Luck comes in with....
- seems to be purely electrical and not CAN related
- Fuse being restricted to engine right side (if true as described and applicable to this VIN).
- All related devices already disconnected... good job on that step!
- Fuse still blowing because unplugged deviced are controlled by GND signal.
- The common rail positive is powered at once by relay.
My guess would be to...:
- focus on the wiring harness for a pinch or shafing and the like
- Try to trace the engine harness in question where it bridges over to chassis
- Can you continuity test with a DVM buzzer and wiggle the line while listening to the tone
- Compare that with engine Left bank circuit.
Test, test and... test.
✌️
Last edited by CaliBenzDriver; 11-15-2021 at 09:26 PM.
11-15-2021, 03:10 PM
W212 Fuse 23 keep blown
