Hello,

I am having a similar problem to ones found in the following posts:
[ul][*]https://mercedesforum.com/m_8762/tm.htm[*]https://mercedesforum.com/m_52462/tm.htm[*]
http://www.benzworld.org/forums/r170-slk-class/1191515-help-intermittent-start-engine-stall-problem.html?highlight=died[/ul]
My SLK230 will randomly choose to not start sometimes(no crank, no sound, just some loud fan noise from under the hood) and itstalls out on me somtimes while driving. It finally didn't start for me last Friday night for about a 1 hour period and I had it towed into the dealer. Of course it started this morning when the dealer tried it and they said it has been starting every time they tried it today. I had it in a couple weeks ago for the same thing (except I was able to drive it in that time) but they said no codes were showing. This time they are saying that three codes are showing: C1022, B1701, B1040. They are wanting to replace the Engine Control Module and the K40 relay. altogether they are saying it will be $1734!!!! for just the K40 they are quoting $263.

I told them about what i had found online about the Crankshaft Position Sensor but they are saying that since it is not cranking then it can't be that.

Not sure what to do from here, can anyone shine a little more light on these codes (from what they told me that have to do w/ CAN communication with the ECM). Should I override their suggestion and instruct them to just order and replace the CPS? Any help would be appreciated. Especially from those with prior experience with this problem. Thanks.

 

Hi,
I don't have a silver bullet solution.

However i believe the key is "intermittant" and "no crank".

The CPS is when you have crank but no start.

C1022 is likely a communication error but I don't have the actual code definition i.e. between what modules. Maybe the dealer told you? Possibly the immobiliser.
Once again I don't have B1701 but 1703 is the immobilser.
B1040. I don't have a definition.

You state no crank.

Do the usual warning lights illuminate and do they remain illuminated when you attempt to crank or do they dim out / flash etc. If so a main battery connection / starter motor solenoid etc would be on the hit list.

Maybe the "no crank" is actual "no power" since the instrument warning lights are also not functioning.

Please try to add in some more data. e.g. Make, model, mileage, history and if you have the exact code definitions. The dealer "print out" gives this. I'll add it to my less than comprehensive list of body / chassis codes.

In the interim I would check the main power cable from battery to starter motor at each connection point.
I would remove, check, clean and replace all fuses/relays etc.
I would unplug, inspect replug the connections to the main EMS and ignition switch etc.

It is possible that a module has gone faulty but once these units "burn in" they are extremely reliable so I feel it is more likely an external connection. Dealer often replace a unit and it is the unplugging/replugging that cures the problem, not the new unit!

Could be the k40...this provides the start sequence...not just the fuel supply which most people associate it with.

Is the problem always when hot or cold or just intermittant and engine temp is irrelevant?

Stuart.

 

It is a 2000 SLK230 with sport package, it has about 64,000 miles and i have only had it since August 06. i haven't had any "real" problems (tail light recall, drivers window came off track) up until now. i don't believe its the battery or anything power related as everything electrical works fine when attempting to start the car - all lights come on, radio works, etc.

The only error described to me was C1022 and it was a communication with the ECM on the CAN bus. Not sure about the other two, but the immobliser was never mentioned.

Maybe I will have them replace the K40 relay and unplug/replug the ECM and give that a try. But please reply if anyone else has any other info. Thanks.

 

Hi! I didn't get much respond in this forum at that time to my question which is the same as your question now. But I did read some of the previous comments about the car that wont start. Your problem described was exactly the same as mine. I had the SLK 230 1999 sport package. I didn't have them diagnostic at that time b/c from what I heard if they couln't figure out the problem they still charge you for the diagnosis fee or if they found the problem, the dealer still charge you for the diagnosing fee ontop of what they are going to fix. So I was still driving on and off. Up until 6 months later, I had a rear-end accident. I got hit by someone. I brought it to the dealer for the back bumper to fix and it died at the MB bodyshop which associated with the Cherryhill-MB dealer. They had the mechanic came to diagnose the problem so they said it was the control mole K40 relay. So I had them replaced. Up until now the car was fine after that for 5 months. But just 2 weeks ago, when I started the car, I heard that fan noise under the hood again but nothing else happen so far. I hope nothing gonna happen again.

P.S. So I guess your problem probably the K-40 thing. They charged me about $225 including the labor. One more thing, when I picked my car up after they fixed, a panel was missing in the trunk and the trunk won't close and they were trying to blame that it was like that when I brought it in. I think they tried to mess my car up and say that if I want it fixed I had to pay for it. I had a big argument with those guy. I had to call the manager of MB Cherry Hill, the MB headquarter so finally they put it back together the way it was. I was stressed out at that time for a few weeks just to clear everything with those guys. So make sure bring your car to the place you can trust and make sure those people dont' rip you off because they think you driving Mercedes so you had a lot of money. Just a tip to watch out. Let me know how things work out for you.

 

uofmrapper.

So "power" remains on during "no crank"

You didn't reply to the following.
... Is the problem always when hot or cold or just intermittant and engine temp is irrelevant?

The other post also stated... "Fan noise under the hood"
Are you referring to the electric cooling fan. Is engine hot or cold?

Stuart.

 

Yes, I did say my car symptoms was the same with the slk230 2000. Doesn't matter hot or cold with the engine. Usually after I drove for 5 or 10 min then stop by someplace then couldn't restart or just died in the middle of the street.

 

CPS or K40 relay

Bazzle

 

It was K40 relay that was replaced in my car.