RNSL65

Strange engine problems.
My beloved car (Sl65AMG) has now got the following problem:
Cold startup is fine, driving around for approx one hour fine, full acceleration and driving is fine - engine ok! But then suddenly MIL light on and almost all power are gone + strange sound in the exhaust (like only 6. cyl. is running). Right side bank (6 cyl.) running fine, left bank, some or all cyl. not running correctly. The smell from the left tailpipes (left bank) is unburned fuel, the right pipe (right bank) is ok! The below codes are stored.
Switch off and on the ignition – or restarting engine does not change the behavior. But waiting approx 1 hour to cool engine down, it starts up fine, engine ok – nothing wrong, but then after ½-1 hour of driving the whole story repeats!
Please help!
P2050 Misfiring,damages TWC P0300Lamp&Stored&Current
P2057 Misfiring of cylinder 7,damages TWC P0307Lamp&Stored&Current
P2058 Misfiring of cylinder 11,damages TWC P0311Lamp&Stored&Current
P2059 Misfiring of cylinder 9,damages TWC P0309Lamp&Stored&Current
C1A00 ?
C1B00 ?
C1C00 ?
U3400 ?
P2043 Misfiring P0300Lamp&Stored&Current

TMAllison

Not much love for you today.....out of my element, but I'll try.

Does a V12 have two crank position sensors? If so, one bank may be bad.

C codes are chassis codes.
U codes are CAN or BUS codes.

None of them are on my lists.

Ausmbtech

The ignition control unit and the ignition coils are common to fail when they get hot. Usually it just affects one bank at a time. This type ignition system isn't something you really want to be touching unless you are very familiar with it as it runs around 80,000v when running and to remove the coils is a bit more involved than it appears.


Best to be visiting your local dealer.

RNSL65

Good point, I'll ask the dealer to hear their opinion! I'll let you know what we find! Thank you!

RNSL65

The car only have one cranck position sensor!

I’ve done some measurements on the ECI system - output from ECI power supply (before the coil pack).

Then the fault are present (left bank of cylinders not running correctly) the 180V and 23V output from the ECI-Power supply to the left coil pack is missing. When engine runs normally (after approx one hour switch off), the 180V and 23V are back on!

This should indicate a bad ECI power supply, but I don’t know if the ECU tells the ECI-power supply to shot down?

RNSL65

I've now done a ECI power supply rewiring, swapping the 180V & 23V power from left to right bank and vice versa. The faults are present, the left bank coil still shows up to be the faulty one!
StarDiag tester showed the same error codes as my EU702 tester did!
Next move is a new coil for the left cyl. bank!

CoupeLeicht600

Coil packs, ignition related problems suck. Last time that happened to me, it ran about $7000 for my 02 CL600...V12s are ridiculously labor intensive.

Ausmbtech

Hang on!

If you swapped the wiring and it still says left coil then it's the ECI, if it was the coil then it would now say the right coil is faulty.

RNSL65

I swapped the wires from the ECI power supply (180V, 23V, 12V & GND) from left coil pack to right coil pack, using some homemade connector wires, to check if it was a faulty ECI power supply. As the missing 180V & 23V still remains on the left coilpack and the ECU shows the same error codes, it's the left coil pack that is faulty. If it was the ECI power supply that was faulty, the voltage would now be missing on the right coil pack!

Found part no. for the coil packs A2751500480 (right) and A2751500580 (Left)!

mbmastertech

to me it doesnt sound like a coil problem, The 65 engines, have some problems with fuel boiling in the fuel rail. Updated fuel pumps and fuel pump module out now for that. The other problem is that chances are there is some air in you intercooler cooling circiut. That will cause missfires and shut down cylinders if 2 or more missfires are detected. Coil issuse were a problem on the old v12 non turbo engines. not the v12 twin turbo.

RNSL65

The dealer diagnosed it to be the ignition coil unit, and changed the unit, but the fault was still present! Then the ECI power supply was changed, and now the fault is gone. This also is the logically solutions to my measurements where the 23V and 180V was missing!

nanochow

Glad your problem got fixed, but it seems from your previous experiment of swapping the left and right ECI power supply channels, the ECI power supply was vindicated and the problem was still the left coil pack?