Batter/Alternator issue + P0272 and P0365
I have also been hearing a strange ticking noise coming from the front right of the motor, just by the left intake tube (if looking from the front). It has gotten progressively worse, and seemed to get even worse yesterday. This morning I turn the car on the the batter/alternator warning light came on immediately. I drove the car to Autozone to get the battery and alternator checked, and the battery was undercharged. When I get home, I decided to use my Torque app on the phone to check for codes. Sure enough there were two of them,
P0272 - Cylinder 4 Contribution/Balance Fault
P0365 - Camshaft position sensor circuit B
All I can think of is that oil got into some of the sensors and caused some sort of short. The ticking could maybe be the ticking of an ark/short? I am not entirely sure. I have also noticed that my fuel economy sometimes averages far lower than normal, not sure if that could be any sort of indication.
I have a long weekend trip planned for after thanksgiving, and don't want to be driving the car up if there are any chances of me getting stranded.
Any idea? Any help would be appreciated. Thanks!!
Thank you in advance for any ideas people are able to put forward.
Once the car is under throttle (both highway and city) it drives beautifully. It does not shake or stutter on the highway and is as smooth as the day I got it. It also starts ups without a hitch. A thought was that some of the oil managed to seep down into cylinder 4 causing some sort of problem. My worry is the battery/alternator warning coupled with the ticking and sometimes rough idle.
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P0271 = Cylinder 4 Injector Circuit High
P0272 = Cylinder 4 Contribution/Balance Fault
P0365 = Camshaft Position Sensor "B" Circuit (Bank 1)
Right - The injection on cylinder 4 is not pulling it's weight - likely running lean - could be a dirty injector or bad connection - ticking you are hearing might be the injector itself. 365 is self explanatory.
Before we do anything both these problems could be caused by low voltage. Please charge the battery properly with a charger & ensure that the alternator is charging properly. You don't say whether Autozone confirmed it was charging.
When you lost your oil cap did you get oil all over the engine harness? If so you need to clean everything thoroughly.
Things to do/check:
- Charge battery at low rate overnight - so as not to surface charge it.
- Clean harness if necessary.
- Put Techron Concentrate in the fuel.
- Check fuel pressure on the injector rail at the schrader valve while cranking. s/b 3.8 bar
- Listen to the injector on Cyl 4 with a screwdriver against your ear & report.
- Check wiring to the injector.
- Pull the injector & see if it is atomising fuel properly - have injector cleaned if you can't wait for fuel to do the job.
- Worse case is replace the injector.
- Replace your cam sensor magnet on the exhaust cam of Bank 1 - I suggest you replace all 4 - see Johnand's thread for method. Do not replace the sensor - only the magnet.
https://mbworld.org/forums/c-class-w...-bank-1-a.html

Good luck & make sure that voltage from the battery is correct FIRST.
Bank one always contains cylinder one in OBDII regime.
Last edited by Glyn M Ruck; Nov 21, 2011 at 10:06 PM.
Oil did get all over the harnesses, but still haven't had time to clean up the wiring. My appointment got moved to next monday at 8 am. I will do everything I can before then, but do you see any major risk in driving it until then?
Thanks again for the help.

Last edited by Glyn M Ruck; Nov 22, 2011 at 09:14 AM.
I will keep an eye on it as I don't want to get my hopes up, but after about 10 minutes and 4 to 5 miles, the light has not returned
My alternator visit workshop light came on randomly last night and I felt a jerk in the car while driving on the highway. I quickly pulled over, turned off the car, restarted and the light went away. I need to visit the shop tomorrow morning, and am trying to research ahead of time.
Only major difference is that I drive an m271... but have had oil issues in the past that were supposedly fixed and cleaned in relation to the cam sensors by the dealer months ago. However, this is the first time I received this error.
I'll see what codes are behind my current and post CEL. Previously, I have been ignoring it because it is typically a harmless p0420... but others may be there too this time around.
only CEL was from my P0420 O2 sensor (nothing else)...
they said that my belt, alternator and battery needed replacement at a quote of around $1400.
i called around and am getting the same work done at currys auto for $1000 and am milking the MB loaner since I had to pay the $130 diagnostic... and will swing my car by there for the car wash to get my moneys worth. Not the best deal in the world, but still saved a couple hundred...
I just hope this fixes the issue and is the last major $$ I gotta drop into maintaining this thing. So much for the Koni's... Looks like my money from selling the CLS wheels and the Kleemann Headers are going into this.
1. check first ground , power , signal wires of your your sensor
2. if ok , try replacing the sensor, clear codes and see if it returns
3. if it returns, probably your wires is contaminated with oil and probably short. clean them, clear code see if it returns
4. if it returns you might need to use oscilloscope to be for scientific to see if the proper square wave signal is being send by camshaft sensor towards ecu.





