C230K Supercharger problem?

[Camping]

C230K Supercharger or other problem?

Hi,

A friend asked me to look at his C230K W202. At first I thougt it was a MAF problem, but here are the symptoms and actions taken:

- Driving slowly and slow response on throttle, car is going fine
- High throttle @ low revs or driving above 4000 RPM performance is poor
- Supercharger was very noisy and had fault code on magnetic coupling
- Recondisioned supercharger, much better i.t.o. noise
- Magnetic coupling on supercharger kicks in when ignition is on and does not release when engine is runnig at idling (stays engaged all the time)
- Coupling resistance about 4 ohms
- Checked continuety to ECU and power to coupling, fine
- Checked points on valve and all fine except for connetion from ECU (stays on 0.6V even if throttle is turned to max, should increase in value when throttle is opened)
- Swapped MAF with two secondhand units and no difference
- Only fault that appears immediately when started is the magnetic coupling, thereafter misfiring, etc.

At this stage I think the ECU is faulty or more likely some signals to the ECU that are causing it to send the wrong signals to the Supercharger and its valve.

Will appreciate any help or experiences.

Tks
Johan

 

[bigasotonuk]

Hi,
What year is this C230K?

 

[Camping]

1999 ......

 

[bigasotonuk]

Hi,
So just to confirm your car has a 3 button electronic key?
Not to sure on this year vehicle as mine is a prefacelift model and one of the things that differ is the way the supercharger is actuated, i always believed that the later car supercharger was always in circuit as long as the engine is running, so you may be on the wrong track regarding this.
Though i,m a little confused regarding your sympton's, but do check all your intake ducting is clear of oil contamination as breather problems can put oil into it causing the MAF to become contaminated and could cause running issues. Sorry just re-read your post and seen you have replaced/tried the MAF.
The valve i presume you are talking about is the throttle control valve, these are not unheard of failling and i believe can be repaired, mine though not completely electrically operated like yours responded very well to cleaning.
You say that it has problems above 4,000rpm, it does go above this? as there is a feature on the car that will not allow it to rev over 4,000rpm when in neutral/park, and when this has occurred in normal driving operation i believe it was traced to a faulty ECU.
You say there was a fault code on the mag coupling of the supercharger was this read with a generic code reader? as i would recommend getting it read with the proper MB STAR computer before doing anything else as they can pick up far more info than a generic code reader.
I,m sure if i have wrongly assumed/diagnosed anything there will be someone along to correct me.
Hope this has been of some help to you, keep us posted how you get on.

 

[Camping]

Hi,
So just to confirm your car has a 3 button electronic key?

Yes it is 3 button

Though i,m a little confused regarding your sympton's, but do check all your intake ducting is clear of oil contamination as breather problems can put oil into it causing the MAF to become contaminated and could cause running issues.

The MAF does show oil contamination, but the others that I tested with were clean.

The valve i presume you are talking about is the throttle control valve

No, I am talking about the valve on the air filter that works with the supercharger. I think it is called the supercharger bypass valve.

You say that it has problems above 4,000rpm, it does go above this? as there is a feature on the car that will not allow it to rev over 4,000rpm when in neutral/park, and when this has occurred in normal driving operation i believe it was traced to a faulty ECU.

It has a manual transmission. It does it both while stationary and when driving.

You say there was a fault code on the mag coupling of the supercharger was this read with a generic code reader? as i would recommend getting it read with the proper MB STAR computer before doing anything else as they can pick up far more info than a generic code reader.

It was read with an Autoboss Star scanner which is claimed to be OEM coverage for MB.

 

[Camping]

Just spoke to a local guy who specialises on these type of faults and explained all the symptoms and actions taken. He claims that it is definately a faulty ECU. He talks about repairing it since it cannot simply be swapped with another ECU. Does that sound right?

 

[bigasotonuk]

Hi,
Yes the new ECU would have to be coded to the car, so yes he is correct in what he says. Lets hope this sorts the problem for you.

 

[Camping]

Problem was solved by fixing the ECU and replacing the MAF.

 

[bigasotonuk]

Glad its been sorted,
thanks for posting back on the outcome.

 

[Danvir]

C230k 1999 model

Hi,

A friend asked me to look at his C230K W202. At first I thougt it was a MAF problem, but here are the symptoms and actions taken:

- Driving slowly and slow response on throttle, car is going fine
- High throttle @ low revs or driving above 4000 RPM performance is poor
- Supercharger was very noisy and had fault code on magnetic coupling
- Recondisioned supercharger, much better i.t.o. noise
- Magnetic coupling on supercharger kicks in when ignition is on and does not release when engine is runnig at idling (stays engaged all the time)
- Coupling resistance about 4 ohms
- Checked continuety to ECU and power to coupling, fine
- Checked points on valve and all fine except for connetion from ECU (stays on 0.6V even if throttle is turned to max, should increase in value when throttle is opened)
- Swapped MAF with two secondhand units and no difference
- Only fault that appears immediately when started is the magnetic coupling, thereafter misfiring, etc.

At this stage I think the ECU is faulty or more likely some signals to the ECU that are causing it to send the wrong signals to the Supercharger and its valve.

can the magnetic coupling be repaired and the supercharger serviced?

Will appreciate any help or experiences.

thanks

danvir

 

[Camping]

Tried to send you a private message, but it did not want to go through. Yes it can be serviced. Call me on 082 805 5895 (this number will be removed from this post soon)