Hello,

I have a 2003 (1st gen) w203 C180 Kompressor that I'm having some electrical problems with. I would greatly appreciate any feedback you can give.

I'm not sure if these issues are related.

1. Check engine light coming on. Approximately once a week the check engine light is coming on for anywhere up to 1 hour then goes away. There is no change in power from the engine when this happens. I have the upper and lower engine breather hoses replaced about 6 months ago by a MB dealer.

2. Cruise control has stopped working. A few months ago at the time I had a brake light out the cruise control stopped working all together. I thought this was because the ECU wouldn't engage the cruise control because it could see an error in the braking electrical system but since replacing the globe it still doesn't work. The speed limiter function still works however.

3. Vehicle starting issue. A few months back we had an issue with the vehicle starting. If I turned the ignition key quickly to start the vehicle the starter motor wouldn't engage long enough for the vehicle to start. Turning the key slowly, having the ignition on for approximately 5 seconds before cranking would usually work. One day the car had great difficulty starting. I checked the voltage of the battery, 10.1 not running and 14.0 when running. I replaced the battery and the vehicle starting issue went away for a month or so. Now the starting issue is back. It is more noticeable after the vehicle has been driven and when the engine is warm to hot. I have also replaced the batteries in the key/remote but this made no change.

4. Alternator light. Every so often the alternator light will come on and go away 10 seconds later.

5. ESP/ABS Not available, ABS light flashing. Only recently when the ignition is turned on but the engine is not running, a clicking noise can be heard either behind the top of the dash or in the engine bay. After starting the engine the ABS light on the dash starts flashing and a message is displayed that the ESP/ABS in not available. Both the flashing ABS light and the message on the display go away after about 10 seconds.

6. Radio turning off. This sounds like an earthing issue to me. The radio is turning off when the indicators are used. A slight pop can be heard and the display on the radio goes black and comes back on a few seconds later. This also happens sometimes with the wipers but not as noticeable as with the indicators/turn signals.

I've read in another thread that some of these problems could be being caused by the cam adjusting magnet leaking oil onto the ECU harness?

If you could give advice to any of the points I would really appreciate it!

 

For the check engine light get the codes for us. for the alternator error i would say you have either a bad voltage regulator or alternator is dying either way have it tested. fix both of these and see what happens with starting issue. as for the esp/abs that could be so many things really need a dealer with star to fix that unless someone else has some ideas.
Where are you located that might help us help you as well as millage.

 

I'm in Sydney, AUS.

Is there a way I can get the engine light codes or do I have to visit a dealer etc?

 

sounds like alternator. If new battery died quickly then its not recharging. Bring your car to any auto parts store and have them test the alternator.

 

sounds like a broken seat controller is draining the battery. If your having 10.1 volts at start up the car shouldn't even start..

 

Looks like I have found the problem.

There is a fused distribution block near the battery. After pulling it apart I found that one of the cables has obviously had a poor connection and has slightly melted. This would explain why most of the fuses on the drivers side are showing 10.5v when the engine is running. I'm hoping this explains the poor voltage supply at the radio, the intermittent check engine light and ESP not available warning too. I'm off to Mercedes parts in the morning as I broke the fuse trying to get the crispy chicken cable undone. Also I have to put a new terminal on the cable. (I hope there's enough slack) Pics below.

Will let you know the outcome tomorrow!!

 

Could be - Alternator is suspicious.

 

Sorry should have mentioned: With engine running Battery 13.6v, fuse panel in boot 13.6v, fuse panel drivers side in the engine bay 10.5v. And from what I can see I'm thinking this cable runs to the drivers side from this fuse block.

Only problem is Mercedes only have 1 of the 200A fuses in the country and it's in Western Australia. (Nice work Mercedes)

 

A wrecker may have one .

 

No fuse - Yugh!! Regulator should cut in at just over 14 volts.

 

THAT WAS IT!!!!!!

Radio issue GONE! No ESP available issue GONE! Check engine light GONE!

That could have cost THOUSANDS if I'd sent it to Mercedes!

WOOHOO!!!

 

So it was just a messed up cable and fuse? Good work man

 

Thanks, Yeah I'm really stoked. It's been driving me crazy for months!

Here's some pics ENJOY!!!

 

van daviz, glad to see you've resolved the problem with the car.

I know how it feels to resolve an annoying [and possibly an expensive] issue by yourself at very little expense. The primary purpose of this forum is to share these experiences. Excellent !!

 

Great news! - Almost looks as though some battery acid was spilt on those connectors.