C-Class (W203) 2001-2007, C160, C180, C200, C220, C230, C240, C270, C280, C300, C320, C230K, C350, Coupe

Check Engine light after replacing the voltage regulator

Old Aug 25, 2014 | 01:12 PM
  #1  
Cruel-Merc's Avatar
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From: Lebanon
2009 C350
Check Engine light after replacing the voltage regulator

Hello folks, i have a c230k 2005, 2 days ago the alternator/battery flashed red when i first started up the engine at morning.The error went after driving for around 15.000Km,everything seemed normal.Next day i went to check on the Alternator and was told to replace the voltage regulator as a first step before replacing the whole alternator.

After installing a new VR, the check engine light came on and the car lost most of its power when driving it, it became so slow but weird thing was that everything was running good, such as lights, radio,etc...checked the alternator voltage and it was running fine, around 13.5V , the next day i had to scan it and the scanner came with an overvoltage error as i recall.Right now, i have no idea what to do? replace the whole valeo alternator and get a new Bosch one? or maybe the problem moved somewhere else , i.e. Kompressor? im in real need of help here.
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Old Aug 25, 2014 | 06:56 PM
  #2  
Glyn M Ruck's Avatar
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
These cars are extremely voltage sensitive.

First thing to check. Did you fit the correct VR for your VIN?

There are 3 different VR types these days.

There are 3 variants:

MFR (multi function regulators)
LIN (local interconnect bus)
BSS (bit synchronous bus)

BSS and LIN are used depending on the engine ECU type
either ME2.8 or SIM4, these regulators actually communicate with the engine ecu and transfer information between each other, the engine ecu has control over the alternator to be able to control the torque loading for emissions requirments. Especially during warm up.
So you cannot swap an alternator with a BSS regulator with one with say a LIN bus. No communication or faulty communication will take place.
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Old Aug 26, 2014 | 06:29 AM
  #3  
Cruel-Merc's Avatar
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From: Lebanon
2009 C350
Originally Posted by Glyn M Ruck
These cars are extremely voltage sensitive.

First thing to check. Did you fit the correct VR for your VIN?

There are 3 different VR types these days.

There are 3 variants:

MFR (multi function regulators)
LIN (local interconnect bus)
BSS (bit synchronous bus)

BSS and LIN are used depending on the engine ECU type
either ME2.8 or SIM4, these regulators actually communicate with the engine ecu and transfer information between each other, the engine ecu has control over the alternator to be able to control the torque loading for emissions requirments. Especially during warm up.
So you cannot swap an alternator with a BSS regulator with one with say a LIN bus. No communication or faulty communication will take place.
Makes sense to me, how do i know what type of VIN and VR please?i still have the old VR..
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Old Aug 26, 2014 | 09:56 AM
  #4  
Glyn M Ruck's Avatar
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Read your VIN through the windscreen of your car & give it to the dealer you buy your new VR from.
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Old Aug 26, 2014 | 10:21 AM
  #5  
Cruel-Merc's Avatar
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From: Lebanon
2009 C350
Originally Posted by Glyn M Ruck
Read your VIN through the windscreen of your car & give it to the dealer you buy your new VR from.
alright, got that.Thanks man, hopefully i wont have to get a new alternator.
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Old Aug 26, 2014 | 10:47 AM
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From: Toronto, Canada
2019 C300 Wagon; '75 Triumph TR6; previous: 2004 C230 6spd sold after 17 years of driving
I bought my VR from the link below for my 2004 c230 for about $56 at the time (it was $205 at the dealer in Canada) and had no issues it has been running for 4 years now. It is an OEM Valeo component.

http://americanenginesco.com/

There are 2 versions (I bought the first one)
http://www.americanenginesco.com/mer...-sg12b062-oem/

http://www.americanenginesco.com/mer...leo-oe-593395/

Last edited by Boom vang; Aug 26, 2014 at 10:51 AM.
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Old Aug 31, 2014 | 06:05 AM
  #7  
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2009 C350
Fixed it guys!! it was a loose kompressor hose , just plug it back into the other side and car worked like a charm. Thank you for all the tips and help folks. Appreciate it.
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Old Aug 31, 2014 | 11:34 AM
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Pleased it's sorted.
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