renraw

Hi Everyone,
I recently just bought a 05 CLK500 and its been running great. Coming from a 03 C320, it was an awesome upgrade for me.

However, as I was coming home tonight, the ABS indicator light turned on and the monitor shows "ESP unavailable see manual." Those are the only two things thats wrong, there are no other warnings or malfunctions.
I don't have any warranty on it, so I would like to fix this myself if i could.

I have read pretty much all the threads on the forum about this issue and read all that I can from a google search on the subject and these are the few things I came across:
1. Could be brake light switch - is it easily changeable?
2. Have something to do with OVP relay?
3. Some wires near the front wheels?
4. Reseting by wheel locking left and right a few times - i tried this but doesn't seem to work... how many times should i turn it??

If you have solved the same or similar problems, I would greatly appreciate it if you teach me how you did it.

Thanks!

rcompart

ESP requires the steering angle sensor (the thing you're dialing in when you turn the steering wheel lock to lock) whereas ABS does not so this is probably due to a defective wheel speed sensor. Hope this helps.

Take care

LexDiamonds

Car is maybe stuck in dyno mode?

Supafly

1. Our cars do not have a brake light switch. The "switch" (actually a valve) is located in the master cylinder i believe and it should not fail. Brake light switches (plastic plunger located behind the brake pedal) came on the e-classe and the C-classe.
2. Doubt it.
3. Doubt it.
4. Doubt it. You will need to do this after you replace battery or alternator. Lock to Lock 5x.

I firmly believe that your alternator may not be producing enough voltage. Try checking the voltage while the motor is running aswell as the voltage while the car is off. I bet that either your battery is getting old and needs replacement or that your alternator voltage regulator is not functioning properly.

Edit: Our cars are very picky when it comes to voltage draw...if the required voltage is not produced, alot of diffrent malfunctions can occur.
Cheers.

-David

renraw

Thanks for the advise guys!

I just checked the voltage. When engine off it is 12.5 and on is about 14.5. I checked the voltage through the car's menu screen, so not sure if this is entirely accurate or I have to bring it to an auto store to have them check it.

Does level seem normal? if it is, i'll try just changing the alternator?

LexDiamonds

Replacing the alt. would be expensive when not knowing for sure that is the problem. The voltages you posted are consistant for on/off readings in most vehicles.

I am a MBZ noobie (had my clk for all of 3 months), but the problems you describe strangely mimic the dyno mode (no abs or esp). I would try getting into the dyno menu, turning it "on", starting the car, then turn it off and disable it. It might "reset" whatever is causing the problems.

access the dyno mode with the engine off by turning the ignition to the right 1 position, selecting the MPH/outside temperature screen, then quickly pressing the reset button 3 times.

renraw

Thanks for the tip.
I tried turing on dyno mode and the start the car, then turned it off. When I was driving out of the garage, everything went back to normal.

Then I decided to drive to a shop to get it checked out. They checked it out real quick, cleared all the codes and everything was fine.

Bu about 10 minutes after I drove out, ABS light and ESP unavailable came on again (same as before). I stopped the car for another 10 minutes, started it back up and drove for a minute and its all back to normal. This is really weird.

The used dealership where i got the car from said they recently changed out the brakes, and rotated the tires, didn't change the battery.

Any help is appreciated!!

Supafly

Change out battery....then change out alternator next....100 bux for a battery...300 for an bosche rebuilt alternator. I'll bet on it.

waltermus

I asked a local garage to check why my SRS/ESP lights were on and they were able to identify the broken sensors immediately by plugging into their Star diagnostics. Maybe find a shop that has one? My shop charged me $50.. so it wasn't too bad.

On a side note, My ESP says "Unavailable" .. but that's because my clock spring (steering angle sensor) is broken... its always on dyno mode

whitemb1

please help...lol... the exact same thing is happening to my 07 s 550 4matic.. the light comes and goes.. did you ever get your issue resolved. any info would be greatly appreciated!!

renraw

Hi All,
Thank you for all your help.

I ended up taking my car to my trusted car shop.
They tested the wheel sensors, but it wasn't that. It ended up being that the ESP module was busted.

They hooked up my car with a computer and drove it for a few miles, my front left wheel was giving it a different reading. So they concluded it was my ESP module and it caused the ABS to stop functioning.

I had the module replaced and everything works fine now. No more lights going on and off and the ABS is working fine. The module is a $700+ part and labor cost me around $200. Not too happy about this, but I'm glad the car is fixed.

I read somewhere on the internet that the module malfunction can be caused by not changing the brake fluid regularly... is there any truth to this?