ECU location W209 230K

[leemorgan]

Hi I Have a clk cabrio and have a problem with a misfire at around 2500 to 3000 rpm. I have had an independent diagnostic and told it is missing on 2 and 4 cylinder. I changed the MAF and it seemed a little better but not great. I have now been told it could be a damaged ECU due to a spike in the coil packs. I have changed the packs but this has not solved the problem. Can anyone give me any ideas of the location of the ECU for a part number or any other suggestion of the cause. thanks Lee

 

[BlackC55]

What year 209?

Have you cheked the leads?

Plug caps?

Spark plugs?

Fuel pressure?

Compression test?

Do ALL of these first before thinking of an Engine Control Unit. They are mega money.

 

[leemorgan]

thanks all these things have been checked. I have been told it could be a ERV or a lambda sensor. But because the fault is only on 2 and 4 cylinder it is probably linked to the coil packs. Apparently a common fault. when these spike they damage the ecu. they dont work properly after being replaced due to the ecu being damaged. But this is what i have been told by an ecu repairer. Its a 2001 by the way.

 

[television]

I have not got a 209 230k but on a 208 C230k its 53 in the link
http://www.detali.ru/cat/oem_mb2.as...GM=717.460&CT=F&cat=45Y&SID=54&SGR=080&SGN=08

 

[leemorgan]

thanks television i would assume it would be in the same place. I understand it will either be a bosch unit or VDO. are they interchangeable?

 

[television]

thanks television i would assume it would be in the same place. I understand it will either be a bosch unit or VDO. are they interchangeable?

I do not think that I made my self clear, that is I have no info on a 209 c230k

Are you sure that it is a 209 as I do not think that it is, better to be as exact as possible

 

[leemorgan]

the part number quoted me by a local MB dealer after giving my chassis number is the same as the part number on the diagram Thanks Lee

 

[leemorgan]

Sorry television i have just picked up on my typo I have a W208 cabrio Thanks Lee

 

[television]

Sorry television i have just picked up on my typo I have a W208 cabrio Thanks Lee

Then the one in the link is correct.

Only ECU's marked with both a MB number and a Bosch number are compatible the VDO is not,it will be marked

 

[miro]

Hi I Have a clk cabrio and have a problem with a misfire at around 2500 to 3000 rpm. I have had an independent diagnostic and told it is missing on 2 and 4 cylinder. I changed the MAF and it seemed a little better but not great. I have now been told it could be a damaged ECU due to a spike in the coil packs. I have changed the packs but this has not solved the problem. Can anyone give me any ideas of the location of the ECU for a part number or any other suggestion of the cause. thanks Lee

This engine is M111 based same as the first W203. Therefore I would also check for oil infiltration into the engine harness. It is entirely possible that the cam magnet is leaking oil.

I also recall that igntion coils can damage the ECU on that series. I also know that there is an obscure but easy fix in some cases. There may be some wires touching the engine and after a while they rub through and earth onto the block. Have the wiring harness inspected carefully for wear and short circuits. I think also that the insulation can crack off from other parts of the harness and cause problems too.

 

[leemorgan]

i have checked for oil leaks and everything seems ok.When you say the leads can short out, are you talking anywhere on the wiring loomor on the connecting leads to the coil.

 

[BlackC55]

The coil shorting is not a problem on your car as the coil design is VERY different.

Did you get a bosch Air mass sensor?

Its there any oil in your air intake?

 

[miro]

The coil shorting is not a problem on your car as the coil design is VERY different.

Did you get a bosch Air mass sensor?

Its there any oil in your air intake?

How can the coil design be that different when it is the same engine used in the R170 SLK which had similar problems. It was also the same engine used in the W203 when launched in the USA as the base model.

 

[leemorgan]

Not sure what make sensor i bought as i wasnt aware it madea difference. There is no oil on the air intake.

 

[television]

Its a known fact that non Bosch MAFs can give poor results not even working in some cases

 

[leemorgan]

ok I'll check it when i go home. Any other ideas besides the ECU or does that still sound the most likely.

 

[television]

ok I'll check it when i go home. Any other ideas besides the ECU or does that still sound the most likely.

I refer to your first post where you say that you changed the MAF and there was a little improvement.

The MAF cannot alter or cover up for the ECU. we have known many cars have problems after fitting an incorrect MAF.

As it is always better to start with basics, as most faults are, wait until you check on the MAF

 

[miro]

ok I'll check it when i go home. Any other ideas besides the ECU or does that still sound the most likely.

If you do not diagnose the fault correctly you will damage the new ECU also.

 

[BlackC55]

How can the coil design be that different when it is the same engine used in the R170 SLK which had similar problems. It was also the same engine used in the W203 when launched in the USA as the base model.

Because I know the cars very well and the coil design is different.

 

[BlackC55]

Not sure what make sensor i bought as i wasnt aware it madea difference. There is no oil on the air intake.

Check it is a bosch item. This is a MUST!