Help needed!!!

[Abbaso]

Hi guys
This problem just keeps coming back. When ever I drive the car hard the kompressor clutch disengages always in 3rd at around 4500 rpm. A quick turn of the key brings it back to normal again the code it throws out is P 0803. I've read that it is the supercharger bypass valve. None of the threads I've come across have come up with a definitive solution.
Any suggestions would be greatly appreciated.
Thanks

[RemoLexi]

There may be more to this that's -causing- the bypass valve to stay open (to not boost the engine)

Probably not the valve, could be caused by a transmission issue.

[Abbaso]

There may be more to this that's -causing- the bypass valve to stay open (to not boost the engine)
Probably not the valve, could be caused by a transmission issue.
Thanks for the reply Remo. Yes I've read that it throws that code as a default code.
It's a manual transmission.

[John Jones Jr.]

Hi guys
This problem just keeps coming back. When ever I drive the car hard the kompressor clutch disengages always in 3rd at around 4500 rpm. A quick turn of the key brings it back to normal again the code it throws out is P 0803. I've read that it is the supercharger bypass valve. None of the threads I've come across have come up with a definitive solution.
Any suggestions would be greatly appreciated.
Thanks


Sorry to hear about that Abbas.

I've done a bit of research on that problem and from what I can tell it's usually caused by either a fault in the ECU or possibly the K40 replay. Have a look at this thread too. http://www.benzworld.org/forums/r170-slk-class/1684378-supercharger-fault-help-please-2.html

[RemoLexi]

I have a spare K40 around if interested.

[Abbaso]

Thanks for the link John. My soldering abilities are pathetic to say the least. So there's no way I will take the chance doing it myself. Will check around and see if there's somebody who will do it at a reasonable price.
My question is why does it only happen when the car is driven hard..
If I drive decent but still fast it goes like a dream.

[Abbaso]

Question if I get another ecu will it start the car or will it have to be recoded? There is a 99/2000 model 230K at the local breakers.

[RemoLexi]

It's VIN locked. Sorry but you would have to send it out to be unlocked and after that variant code it for your car / vin.

[Abbaso]

It's VIN locked. Sorry but you would have to send it out to be unlocked and after that variant code it for your car / vin.
Thanks for the info Remo.

[John Jones Jr.]

Thanks for the link John. My soldering abilities are pathetic to say the least. So there's no way I will take the chance doing it myself. Will check around and see if there's somebody who will do it at a reasonable price.
My question is why does it only happen when the car is driven hard..
If I drive decent but still fast it goes like a dream.

No probs Abbas. I suspect the S/c is only disengaging at max torque and I recall Krum telling me that the ECU has an safe guard/protection built in for excessive boost/torque. So, if the ECU has a problem this safe guard maybe it. Remember, I too had sudden loss of boost (S/c disengaging) after dropping a couple of gears at WOT only. Switch off and restart the engine all was good again.

P.s. If you are crap at soldering and looking for someone to do it, try your local computer repair shop. I've used them once in the past on a very tricky repair of a throttle potenitometer and the repair was 100%.

[John Jones Jr.]

Question if I get another ecu will it start the car or will it have to be recoded? There is a 99/2000 model 230K at the local breakers.

It's not a major issue and a fairly common practice if you find a company like these http://www.allcarelectronics.com/ Also, I'd prefer to have my ECU tested & repaired rather than fit a 2nd hand ECU which you'll need to get the unlocked/decoded anyway due to the immobiliser.

[RemoLexi]

How does your S/c clutch look? Maybe it's wiped out ..

[Abbaso]

How does your S/c clutch look? Maybe it's wiped out ..
It looks ok..There's no fibres as such sticking out of the cover. What should I look for?

[Abbaso]

No probs Abbas. I suspect the S/c is only disengaging at max torque and I recall Krum telling me that the ECU has an safe guard/protection built in for excessive boost/torque. So, if the ECU has a problem this safe guard maybe it. Remember, I too had sudden loss of boost (S/c disengaging) after dropping a couple of gears at WOT only. Switch off and restart the engine all was good again.

P.s. If you are crap at soldering and looking for someone to do it, try your local computer repair shop. I've used them once in the past on a very tricky repair of a throttle potenitometer and the repair was 100%.

I've read that ecu's have built in torque dampners there's a company called chiplogic here that advertise removing the dampener. Gonna go s3e them today. Will report back on what they say.

[John Jones Jr.]

Abbas, any news?

[Abbaso]

Chiplogic haven't got back to me. I'm in contact with eurocharged of USA. Emailed Adam of Eurocharged on Saturday he replied today. They can flash the ECU on the C43 without removing the ecu. So hoping it can be done to the 230K as well. Just waiting on he's reply now. Finally fitted the walbro pump aswell.

[John Jones Jr.]

Chiplogic haven't got back to me. I'm in contact with eurocharged of USA. Emailed Adam of Eurocharged on Saturday he replied today. They can flash the ECU on the C43 without removing the ecu. So hoping it can be done to the 230K as well. Just waiting on he's reply now. Finally fitted the walbro pump aswell.

I did check out their site before http://www.eurocharged.com/component/virtuemart/c-class/c230/c230k-2-3-performance-engine-software-w202-detail?Itemid=90

Do reckon the Walbro is quieter than the original Bosch? Did you use a banjo fitting to gt the 90 degree turn or just fit a longer fuel hose to get the turn?

[Abbaso]

I did check out their site before http://www.eurocharged.com/component/virtuemart/c-class/c230/c230k-2-3-performance-engine-software-w202-detail?Itemid=90

Do reckon the Walbro is quieter than the original Bosch? Did you use a banjo fitting to gt the 90 degree turn or just fit a longer fuel hose to get the turn?
The walbro is quieter and no I just used a longer hose to make the bend.

[John Jones Jr.]

Abbas, a little update. I decided yesterday to remove the K40 reply unit. I took the casing off and checked all the solder joints (under a lit magnifying glass just to be sure) and couldn't find any cracks or fusing.

[Abbaso]

Abbas, a little update. I decided yesterday to remove the K40 reply unit. I took the casing off and checked all the solder joints (under a lit magnifying glass just to be sure) and couldn't find any cracks or fusing.
Glad to hear you finally working on the 230K John. Yeah it seems only the slk's have that problem. I had to deal with voltage regulator going bad on my alternator this week and could not find a new Valeo one anywhere. So matched a set of brushes filed them down to fit and got a friend to solder them on cost about 2$ and works like a champ again. pray you have have the Bosch alternator in your car spares are so much easier. Will be looking out for a 115 amp used Bosch alternator to upgrade in the future.

[RemoLexi]

Speaking of alternators I may have a spare bosch off a 99' komp.

[John Jones Jr.]

Glad to hear you finally working on the 230K John. Yeah it seems only the slk's have that problem. I had to deal with voltage regulator going bad on my alternator this week and could not find a new Valeo one anywhere. So matched a set of brushes filed them down to fit and got a friend to solder them on cost about 2$ and works like a champ again. pray you have have the Bosch alternator in your car spares are so much easier. Will be looking out for a 115 amp used Bosch alternator to upgrade in the future.


Abbas, it might be worth bearing in mind that you current alternator is spinning faster due to having the larger crank pulley. Don't know what real difference that makes but just though I'd mention it. Anyway, why are you upping the amp rating?

[Abbaso]

Abbas, it might be worth bearing in mind that you current alternator is spinning faster due to having the larger crank pulley. Don't know what real difference that makes but just though I'd mention it. Anyway, why are you upping the amp rating?
No particular reason just see it as I got to get a Bosch alternator as spares are available might as well just up the amp from 90 to 115 while I'm at it.

[John Jones Jr.]

No particular reason just see it as I got to get a Bosch alternator as spares are available might as well just up the amp from 90 to 115 while I'm at it.

Yeah, why not.