apocalypse

Hi, new to the forum. Greetings from Finland.

I own a year 2010 model W204 Mercedes CDI 200. Engine is OM651. It's a high mileage car but it drives like new. It's my fifth Merc, I love these cars. Obviously you get some issues every now and then.

My power steering is now acting weird. Occasionally it works fine but sometimes when I steer it becomes stiff at times. My car mechanic took the error codes and they showed that the power steering pump is giving constant short circuits. When I start the car I get an error message "Power Steering Malfunction, check manual".

So... the pump might be bad. Or then there's some issue with the pump not getting electricity... bad connection or whatever. That's what this very qualified Merc mechanic said. That sounds logical as the power steering is occasionally working just fine... until the stiffness comes back.

Fluid level is ok. And the fluid is correct quality.
Belt is ok.
ZERO noises or whines anywhere. It's all silent and engine sounds fine... it's just this stiffness coming back and forth.
I already rolled the steering from one end to another when the car was parked in P gear. I heard this would eliminate the air bubbles being in the system (no idea if this was even accurate information but I tried that too).

I'm taking the car to mechanic next week for proper inspection anyway but meanwhile I could try shooting CRC electronic clener to the wiring. I only see one wire connection going to the power steering pump, which is located right below the pump. Anything else I could try?

Cheers. And happy new year!

apocalypse

Turns out the power steering malfunction is connected to the ABS module. I have to replace the whole ABS/ESP main module which is 1400 Euros.

ABS work fine, ESP work fine... no issues with them but power steering goes occasionally off and gives these short circuits.

I heard you can't have an used part because the car's VIN code / serial number (or whatever) is coded inside the module. If you put another module in, the car won't accept it because the serials will not match. Then it will announce all malfunctions (ABS, ESP, etc.)

Any ideas?

apocalypse

Okay, I got it through STAR.

And the problem is:

PART Y10/1
POWER STEERING PUMP CONTROL VALVE

Check if there's a connection problem.

This is the only code that STAR gives. The error had happened 5 times during the last three days (or so). Like I said, most of the time the power steering works just fine.

And also... as stated before the pump has been checked. I don't know if that part (control valve) is inside the pump though. When I google part Y10/1 I get stuff like this (which are located on the steering rack):

http://www.benzworld.org/forums/atta...tric-valve.jpg
https://c1552172.ssl.cf0.rackcdn.com/368706_x800.jpg
https://c1552172.ssl.cf0.rackcdn.com/368706_x800.jpg

But on W204 200CDI this part is inside the pump (or integrated to the pump), huh?

apocalypse

Is there another Mercedes forum where I could ask for help? Any help about this valve/solenoid position on W204 appreciated.

alecmascot

With out your VIN this may not be really accurate :
With option code 213, Speed sensitive power steering, there is a valve, Y10 on the steering rack just where the column connects.
A valve repair kit is listed : A2214600184.
rgds

apocalypse

Thanks man.

But the problem is in part Y10/1. Could that be a different part and integrated to the steering pump itself?

My pump has this connection. Could this be part Y10/1?

alecmascot

whats your vin ?

apocalypse

WDD2042011F456636

alecmascot

PART Y10/1
POWER STEERING PUMP CONTROL VALVE
is integrated into the power steering pump :-((
The fault you describe is because the speed sensitive PS turns off and defaults to the heavy setting.
I guess that the fault lies with the PS Pump sensor and not with the ABS ECU.
I take it that you have checked for a bad connection or a broken wire ?
Fitting a used PS pump should be straight forward, a refurbished part is available from MB.
rgds

apocalypse

It has been tested with a new pump and it still gives the same error. So that means the problem is in the ABS/ECU box.

Strange that ABS and ESP work perfectly. And the power steering works okay most of the time.

alecmascot

Y10/1 wiring routes to the ESP CU via two connectors before the ESP CU connector itself.
One is X26 at the front of the cam cover then to X35/6 inside the car on the left hand side.

apocalypse

Thank you Sir. I will investigate.

I also think it's weird that ABS and ESP work but only power steering is just "partly off". That indeed looks like some kind of wiring problem.

apocalypse

This issue has returned again. It went away for months but now it's there again.Power Steering Malfunction whenever I start the engine.

Denis Jonjić

Hi, I have been having the same problem for a few months now. Any luck in getting an answer?

apocalypse

Mine was fixed. I just sprayed electric spray to the both contacts in the main CPU module (or whatever it's called).

That fixed it for a few months until it came back. I sprayed it again and now it's gone again. It's either the wiring or just those connectors that are worn. Bad contact, nothing more. It also creates occasional issues with the mirror turn signals and also makes the dashboard "blinking" occasionally. I hope that helps you as well.

Just remove the cover of that black thing (pull it off) and then detach the connector from the module. Spray and reconnect. Of course there's no guarantee that this works for you but it's worth the shot.