Colin-C230k

Evening All,

My first post here and im hoping you'll be gentle
Im after a little advice and am hoping you might be able to help.
Im the owner of a W203 C230k which i believe has a M271 engine.
About 9Months ago the car started to rough idle and i identified a split air intake hose which i replaced. After this was replaced the problems came.
The car was showing an Engine managment light, so i took it to be read and it threw up code P0335 Crankshaft position circuit A failure i believe was the full discription.
My car went into the garage and was there for around 6months, The mechanic replaced the Crankshaft position sensor and the fault still occured, he checked the wiring and all was working as intended but the code just keeps re - appearing and the car has problems starting.

My first question is, are there any other suggestions you could make that might bring up this fault code that i could check?

My second question and possible fault causer, Having spent some time reading through all this forum i found out about the leaking oil problem from the cam shaft sensors, i poped off the connectors and found a fair amount of oil inside one of them. Im going to replace both sensors and fit all the additional parts that have been suggested but im wondering if this could cause the problem if the sensor was faulty and would it be making the wrong code appear on the diagnostic?

Thanks in advance for any help that anyone could give.

Colin

kimito

hello colin, I had a problem like yours and after a while 2 cilinders fall. As an engineer I wanted to know the reason of it. Searching I discovered that after breaking the intake hose dust started to stick to the valves and after a while they had so much they could not work properly. In consecuence most of the motor had to be open to repair the dameged parts.
Has your car have a loose of power? when the car is not moving do the rpms move above 1000 rpms?.

Colin-C230k

Hi Kimito, thank you for your reply. My car runs fine I'm a sense of the word.
I have no rpm issues or power issues. The problem arises when starting the car, it takes forever to crank over and as such the above error code appears as a Cel then the car goes into limp mode. Everything points towards the crankshaft sensor / circuit but the sensor has been replaced and the wiring checked by the garage the car was in and the fault still stays. I've got the car back now and decided to take a look myself and found oil in the camshaft sensors, I'm wondering whetherthis can cause random faults to show up wrongly on the cars diagnostics.

thanks again for your time.

Colin

Glyn M Ruck

P0335 = Crankshaft Position Sensor A Circuit Malfunction.

If I owned this car I would try yet another new genuine CPS in it - could still be faulty.

If you have oil in the engine harness from leaking cam sensors it can cause all sorts of problems. Check the O2 sensor plugs to see if the oil has got that far. If so the whole harness is saturated.

You need to fit those new sensors, fit the pigtales & clean (difficult) or replace the engine harness. Try & get Benz to contribute. They know it's a problem.

Good luck!

EDIT - does the car ever backfire up the inlet system? That would be indicative of fouled valves & head. Your car is unfortunately in the head/valve fouling window.

kimito

Check what glyn said. I'll wait notices. Good luck.

Colin-C230k

Hi Glyn / Kimito,

Glyn in relation to your post, Im gonna get a new Cps and fit it as you suggest as i agree it could be faulty and im exhausting all other avenues other than the obvious.

From Checking all other sensors i can find no other evidence of oil, ive checked the Inboard and outboard O2 Sensors and the Ecu connector. Any others you'd suggest checking?
I've picked up some Electrical contact cleaner and am going to give the connetions a clean at the same time as fitting the camshaft bits.

Unfortuantely in the Uk where im from Mbenz do not recognise this recall or at least do not recognise it as a problem via my Vin when provided and as such are unwilling to contribute although i strongly believe they should do.

In relation to the backfiring, I have not had any backfiring occur.

Ill update once i try a new Cps at the weekend.

Thanks both for your help

Colin

Glyn M Ruck

OK - You are in the UK. Better Eurograde fuel. Unlikely the head problem. Do those cam sensors, clean up everything with contact cleaner & fit pigtales.

I've been down this road before with a friend's M271. CPS failed & new CPS was faulty. I'm not saying this is definitely the case but I would do that first. Thats why we have OBD.

We had no sooner got the CPS right on my friend's M271 & two months later the inlet cam Camshaft position sensor failed. Code was correct that time so watch for stored codes. Also watch for misfire codes if starting is an issue - (potential dirty MAF or ignition coil packs)

Also make sure that all vacuum hoses are in good condition. If you had a bad vacuum leak it should throw a fuel trim code.

Colin-C230k

Hi All,

Apologies for the slow update, had some issues that needed dealing with before i could get the part to replace.

Well ive now replaced with another Cps and it made no difference.
Same code showing up on the fault reader , Same symptoms when starting.

Any other suggestions i could try?
Is there anything else that could link or throw up this P0335 code thats not linked to the Cps sensor.

Regards

Colin

Glyn M Ruck

If it is throwing a 335 the engine does not know when it is at TDC. This now becomes a wiring or ECU problem potentially. Could be something as simple as a corroded connector. I would also get someone to do a boroscope inspection of inlet valves for deposit build up.

Colin-C230k

Hi Gyln,

Thanks for your advice so far, the last part seemed to hit a small nail on the head.
Having checked the Ecu head connections it seems some of the pins were corroded / covered in crap. Cleaned them up and the fault disappeared.

Getting the car ready for Mot etc and now another fault has reared its ugly head. If i describe whats happening would you be able to suggest any actions?

Car starts fine,

Runs ok then all of a sudden i get 3 warnings pop up on the dash,
They are as follows.

Display Faulty Visit Workshop ..
Coolant Visit Workshop..
Esp Visit workshop.. or something to these effects.

The dash board then goes mental, all rev counter needles and Speedometer needles go straight back to 0 and dont move. Then after a while they reset and all runs okay, then 2 minutes later it happens again etc etc.

Ive connected up my Code reader and i get a pending Code of

P0600 - Serial Communication Link error.

Not sure what has caused this problem and it doesnt seem related as such to the other fault that was cured.

Anything you could think of to look at?

Regards

Colin

Colin-C230k

Bump*

Anyone that can shed some knowledge it will be greatly received

Regards

Colin

Glyn M Ruck

That is a typical control module code. Go back & check all electrical connections you have touched. Esp. the ECU plugs. Do not short anything!

If the instrument cluster is messing around you are corrupting the CANBUS somehow.

Keep an accurate listing of messages & codes & post. The above is not sufficient to diagnose anything.

Check all connectors, modules, plugs, fuses in the front SAM. You might have some light corrosion that can cause mayhem.

Best advice however is to check everything that has been recently disturbed.