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· Registered
2 Posts
Discussion Starter · #1 ·

I have a 2006 C230 Sport with the 2.5L V6 engine. It started randomly shutting down while driving making it very dangerous to drive. Typically it shutdowns after 5 min of driving (approx) after leaving the car to rest for at least 1hr. Otherwise it will last less or not crank right away. When it shutdowns the engine cuts off and I lose power steering and brakes. The dash lights up and then I get ESP failure message and visit workshop. Then I get low coolant message. Once this happens I cannot start the engine again right away. It will not crank. While in ON position the radiator fans will go full blast. I may go into ON position and start all the accessories, but it will not try to crank when put into START. To start the car again I have to pull out the key and wait. The longer I wait the longer the car will drive before this happens again.

The car is good on coolant. When this happens the engine temp is always under 50% so it is not heating up. I have checked the fuel pressure on idle and it stays at around 45 psi solid. I can even increase rpm on parked without any issues on fuel pressure or hesitation. I tried changing the 4 camshaft sensors, with original Bosch, but the problem persists. I do not think this is camshaft, or crankshaft sensor related. This seems 100% electrical. I feel like something is heating up and needs to cool down for the car to start again. It seems as is the ECU detects something wrong and shuts the engine off. Could this be an engine ECU problem? I have read about the ECU overheating. I don't know what else to try, but I know the ECU route is probably expensive...

I do have a few engine codes:
  • o2 sensor codes (downstream) - always been there
  • something about being unable to learn the throttle position

Right now, I cannot read any codes because as soon as I go into ON position the radiator fans go into full speed and I get link error on the OBD scanner. So it seems that the ECU is non-responsive

Any thoughts on this? I am really at a loss on this one.

Thanks in advance!

· Registered
'03 E320, '05 ML350, '11 GL450, '13 ML350
114 Posts
If it has the M112 engine, than it is most likely the Crankshaft Position Sensor.

That part is about $35 and is located on the drivers side of the engine back towards the firewall.

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· Outstanding Contributor , SDS Guru
1998 MB E300TD, 1997 MB E36 AMG, 2001 MB E55 AMG. 2011 BMW 335d
8,714 Posts
He has the M272 engine.

Once this happens I cannot start the engine again right away. It will not crank. While in ON position the radiator fans will go full blast.
That's definitely bad ECU. Find a indy nearby who can replace the ECU for cheap, because otherwise dealer route is like $1800.

· Coupe/Convertible Forums Moderator
CURRENT: 2011 SL550 FORMER: C300, ML350, CLK550 Cabriolet, C240, ML320, 300TD
25,449 Posts
Unplug the coils and try reading codes. If that fixes it, you have a shorted coil which will mess with the ECU.
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