Wiring Fault Maybe??

[FMcG]

Hi just joined the Forum today due to financial worry.

I bought my 2003 Mercedes C180K in July 2007 and I am totally taken with it. (this being my first Merc)

I had a couple of months of trouble free motoring and then the Engine Management Light came on, this was a concern but it went off again in a couple of hours, I just put this down to tiny glitches and there was nothing wrong, eventually this was more frequent untill it came on last month and never went off.

The car drove great as far as I could tell but I have nothing to compare it with.
Anyway I took it to a Mercedes Specialist and they diagnosed a faulty Air Mass Meter as well as leaking Camshaft Sensor Magnets and they gave me a quote for all.
Believing I could save some money I sourced the Air Mass and Magnets, had them fitted by a friend and bingo a couple of engine reboots later the light went off.

2 days later the light came on again so I put it down to maybe the replacement Air Mass Meter being faulty.

I decided I would take the car for a diagnostic at a local garage and the mechanic cannot pinpoint the issue although he has tested the air mass meter and says it is working properly. The codes his computer equipment is generating are

P2020 - Auxilary Heater (Fual Fired) System Disabled
P2400 - Heated Oxygen Sensory 1 Bank 1 Range/Performance

Mercedes were not very forthcoming about these codes but my man believes there could be some kind of wiring fault.

My question, are my issues related to oil in the wiring loom as I have read about?

If so how far do I go replacing parts? or is it just a squirt of WD40 that is required?

Many Thanks in Advance

 

[Ellsy Tanners]

Hello,
Your leaking camshaft magnet, will have leaked oil, into the engine wiring loom and made its way to the engine ecu, and be sitting in the conector for the oxgen sensor. You will need to replace the wiring harnesss or get it cleaned out, and clean up the engine ecu. sorry to break the bad news.

 

[FMcG]

Thanks for your prompt reply and diagnosis.

I assume there is a way of cleaning the wiring Loom without replacing it?

Also I am confused how oil makes it to the ECU, I may be wrong (or looking at the wrong part) but the wires coming from the magnets seem to be lower than the ECU, can oil still get into the ECU?

Thanks again

Fraser

 

[Ellsy Tanners]

The electric current draws the oil allong the wires. there is a adapator plug which should of been installed to stop any further oil coming from the magnet.

I always replace the loom but i think televison knows how to clean it, wait until he comes on and ask him.

No problem.

 

[television]

Some say the harness cannot be cleaned,others do it. You could wash the harness in warm soapy water and then dry it well, though this will not remove any oil in the inside or the wires, with the adaptor plug no further harm can be done.

The ECU can be washed in lighter fuel (refined petrol) just by filling and shaking a few times, if you open the box,then a better job can be made of it. leave it somewhere warm to dry out

 

[FMcG]

Thanks for that Television,

Do you know whether the wiring looms are easy to take out and put back in?

Also the adapter plug you speak of, are they available from a Merc dealer?

Much appreciated

Fraser

 

[television]

Thanks for that Television,

Do you know whether the wiring looms are easy to take out and put back in?

Also the adapter plug you speak of, are they available from a Merc dealer?

Much appreciated

Fraser

Get the adapter plug from MB they wiring loom just unplugs/clips and lift it off

 

[Rory]

Is the Air Mass Meter a genuine MB one?

There are posts quite often from people who buy from eBay or elsewhere but the car doesn't perform properly until an MB part is fitted.

 

[FMcG]

Bought it from Euro Car Parts for 230 quid, the part is made by Siemens and is the same as the original part.

 

[Ellsy Tanners]

Your problem wont be the air mass on this occasion. its to do with oil in the loom, ecu.

The loom is fairly though to change to be honest with plugs and wires only accesible from underneath, only a very compertant diy mechanic should attemp it in my opinion. a good few hours work

 

[BlackC55]

What colour is the engine cover?

Is it silver or black plastic (111 or 271 engine)

If it is the 271 engine (black cover) the oil in the loom problem does not affect them.

Let us know.

 

[FMcG]

The engine cover is black plastic??

 

[FMcG]

Just been on to my local Merc dealer and they say that the problem affects both engine types, admittedly I did see the presence of oil on the loom on the initial diagnosis.

 

[BlackC55]

Just been on to my local Merc dealer and they say that the problem affects both engine types, admittedly I did see the presence of oil on the loom on the initial diagnosis.

Thats interesting.

I did not know that.