Crank position sensor

Tiny
MECEDESSTEVE
  • MEMBER
  • 2003 MERCEDES BENZ C240
  • 144,000 MILES
2003 Mercedes Benz C240 2.6. I replaced a failed crank sensor and it failed in less then 48 hours. I have ordered a new unit from a Mercedes Benz dealer as the first one was not OEM. Is it possible there is an under lying problem that is no showing up on the OBD? The car is a base model with no 4matic and the change out is fairly simple.
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Sunday, November 17th, 2013 AT 2:34 AM

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Tiny
CARADIODOC
  • EXPERT
Absolutely. If you're basing your diagnosis on a diagnostic fault code, they never say to replace a part or that a part is defective. They only indicate the circuit or system that needs further diagnosis. About half of the time a part referenced in a fault code is the cause of that code, but the other half of the time there's a wiring or computer problem. Stretched terminals in a connector, corroded splices, or a corroded wire where someone previously poked a hole in the insulation to take a reading are all common causes of intermittent fault codes. Those things need to be eliminated before suspecting the sensor itself. Corrosion and terminal problems often allow a circuit to work for a while after they have been disturbed

The best way to get an idea of whether a sensor is working without touching it is to view live data on a scanner. If you back-probe a connector instead, you run the risk of wiggling it enough to cause it to work again, giving you false information.
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Sunday, November 17th, 2013 AT 1:08 PM
Tiny
MAXIMILIAM
  • ADMIN
How are you testing the sensor? Are you using an oscilloscope? Checking resistance?
NOTE: If the crankshaft position sensor (L5) was replaced, a re-initialization must be carried out with STAR DIAGNOSIS in the menu item control module adaptations. Also there is a service bulletin on the crank sensor I can give you the rest of the bulletin if need be.

SUBJECT:
C-Class (203.061/064) with M112 (V6) Engine

E-Class (All) with M112 (V6) and M113 (V8) Engine

S-Class (220.170/175, 215.375) with M113 (V8) Engine

Rough Idle / Rough Running / Hesitation / Engine Won't Start

On the above mentioned models, if you encounter conditions of rough idle, rough running, hesitation or engine won't start with the following possible engine codes P2034, P2050, P2051 P2052, P2053, P2054, P2055, P2056, P2057, P2058, is possible that there is moisture in the crankshaft position sensor plug leading to corrosion of the contact pin(s). Please perform the following procedure to resolve.

Hondatech1983
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Monday, November 18th, 2013 AT 12:29 AM

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