PCM exchange like for like

[Der S Class Dave]

Hello all, and thank you for helping me in advance!

My vehicle is a 2004 S 350 petrol 6 cylinder Mercedes in Mint condition.
Well was
Lately the engine control light appeared on my dash, and the engine runs idling. Error codes are
P201D-004
P2050 & P2051

My trouble shooting was
Coil replacement
Spark plug replacement
And fuel injector replacement

Cylinder one is still not entlightning the sparks. There is absolutely no power coming to the coil
Looking further in I bought a PCM from eBay whitch said it will fit my MB but it doesn't hence the numbers on the module do not match.

My question is, if I find the module with the exact same item numbers will that mean I don't have to reprogram the ECU?
Also please advise if anyone had had the same issue and what had been done to solve it?

 

[mioba]

Who diagnosed the fault codes and done the above jobs.

 

[Der S Class Dave]

Who diagnosed the fault codes and done the above jobs.

No, that is not quite the answer I was looking for....

 

[Doug1234]

Probably not the answer you required but he is asking maybe because he has an inkling you do not even need another pcm

 

[mioba]

Exactly.

Reading fault codes anyone can do - oh my code readers says xyz.

Diagnosing them and fixing the cause is another art for many things and may well require live data interrogation.

Otherwise you just end up chucking money down the drain.

From the first code alone - fuel adaptation could be many things - on a whim
-leaking injector
-maf
-regulator valve
-vacuum line

etc etc

 

[Der S Class Dave]

Exactly.

Reading fault codes anyone can do - oh my code readers says xyz.

Diagnosing them and fixing the cause is another art for many things and may well require live data interrogation.

Otherwise you just end up chucking money down the drain.

From the first code alone - fuel adaptation could be many things - on a whim
-leaking injector
-maf
-regulator valve
-vacuum line

etc etc

So if the MAF is faulty that would cause for coil on cylinder 1 has no power?

 

[mioba]

From the first code .........

i assume the injectors were coded?

 

[Der S Class Dave]

From the first code .........

i assume the injectors were coded?

Yes and I changed the one which was faulty. The wired thing is, I swapped the coil's and they work on Cylinder 2, it's only cylinder one coil which has no electric power supply to entlightning the spark plugs, all other coils and cylinder working fine... So after all my trouble shooting, I assumed it's the module PCM

 

[V6Matty]

Yes and I changed the one which was faulty. The wired thing is, I swapped the coil's and they work on Cylinder 2, it's only cylinder one coil which has no electric power supply to entlightning the spark plugs, all other coils and cylinder working fine... So after all my trouble shooting, I assumed it's the module PCM

If the coil work on another cylinder then have you done some basic voltage checks to see if there is continuity on the cables, may be a broken wire somewhere rather than a faulty module

 

[Der S Class Dave]

If the coil work on another cylinder then have you done some basic voltage checks to see if there is continuity on the cables, may be a broken wire somewhere rather than a faulty module

Good point, I'll be back

 

[Der S Class Dave]

All cables checked and all having connection. PCM is ordered and on its way.

MAF ordered just in case.

We tried to check the spark plugs cables, no chance on any. Inahve ordered a set as well just in case.

Back to my original question, can I change the PCM without any additional work?
Possible or not possible

 

[Der S Class Dave]

Just bought myself an endoscope to check if the cylinder might be faulty....

 

[mioba]

Did you check the cables for electrical continuity with a voltmeter, or just a eyeball (looks ok).
Not unknown that the connectors are a weak point and I am sure MB change connectors when changing the cables.

Endoscope for faulty cylinder check - waste of money for those fault codes.

Getting expensive&

 

[Der S Class Dave]

Thank you for your help, I really appreciate it!

All connections and cables are checked with a voltmeter.

You probably right about the waste of money, but I don't want to leave any options out. I opened the PCM and no smell of burns, of that is any use or help....
How do I measure if there is an air leak?

 

[mioba]

Thoroughly inspect all pipes for a crack, split,

in your hand, twist, tug, bend so on.

 

[Der S Class Dave]

Thoroughly inspect all pipes for a crack, split,

in your hand, twist, tug, bend so on.

Thank you.

What to do with the electrical issue on cylinder 1?

 

[mioba]

I am not a mechanic.
I have asked who read codes and diagnosed.
A decent MB indy would have this sorted in no time.

Keep the thread updated with your endeavours and solution.

Cheers

 

[alexanderfoti]

You cannot swap pcms. They are vin coded to the car.

Places like us can clone the old one to a donor new one.

Its best to match the part numbers, but we can check Bosch ecu compatibility and sometimes there are a few other (Bosch) part numbers that are compatible.

 

[mioba]

Thats where it gets expensive usually.
As a side about 5 years ago the ABS module failed in my w220. I was out in Germany then. Got a new one - had to be from factory as needed programming to VIN - wasn't cheap and not much change from a couple of thousand yoyo's