Help! I am about to give up on my R107 350SL

Hi James,

sounds to that your workshop has increased idle-rpm to overcome rough idle of your car. If we shall help you, you should answer questions 1-7 from above. Otherwise I should have magic telemetric hands to heal what is wrong.

Hi Volker,

Am trying my best to get all this info from my workshop however they really aren't competent enough to provide these!

Anyway, after so many months of troubleshooting, now the workshop recommends changing the ECU as part of the connector is burnt. Please see the pics here: www.facebook.com/groups/MercedesR107/per...k/10154891174294801/

What could cause this, and is it salvageable? I need a replacement urgently to get my car road legal so if anyone here has one to ship to Singapore please let me know... I need a 0280 002 004 but I think if it ends with a 001 or 002 it works too.

Merry Christmas all... Cheers! (despite dreary times with my R107)

Hi James,

I cannot look at your picture as I am not registered on Facebook.

If ECU connector is burned, how does wiring harness look like? There should be a reason for that. I could give you another 0 280 002 004 ECU or test and repair yours but I fear that such a failure will happen again. Wiring harnesses tend to break and loose isolation. That can create shortcuts. Other than that I can right now not think why connectors should burn.

Hi Volker,

Apologies, please see the pics below. Hope this is clearer.

I too am so puzzled why this has happened. I have virtually chased every possible lead and left the ECU to the last. And I was quite sure it was functioning OK. More importantly, I don't want the problem to surface again so I want to be sure what the problem is.

Hi James,

that is severe damage ! What I see it is pins 11 and 12. They are shortcut on ECU. 11 is ground IN, 12 is ground OUT to trigger contacts and throttle switch. When they are so burnt, I can only assume that somehow 12V were applied to the cable connected to 12 and thus caused a heavy shortcut. It looks like it has damaged both connector contacts and ECU. In worst case also your wiring harness. It can also have damaged more on your ECU. Being so far away I would definitely recommend you to

1. swap ECU
2. swap 2 contacts in connector housing (you are so lucky that I have just found such contacts after years of searching)
3. verify wiring harness, especially path from pin 12 to T.C. and throttle switch Remove both connectors and measure 12 to ground and +12V on your car. Both should be open. Verify with both connectors applied function of throttle switch and T:C. Still there should be open end to +12V.
4. I can also have a look at your broken ECU whether it has caused the problem. but I do no think so. In that case you need to send it to me DECLARED AS A GIFT. We have such an embarassing customs duties process.

and someone has also opened your ECU. I can see that from missing sealing on those screws.