- Mercedes-Benz C-Class AMG: How to Replace Crank Shaft Position Sensor
Step by step instructions for do-it-yourself repairs
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Crank Shaft Position Sensor DIY with PICS

E63 Biturbo, UPD Cold Air induction kit, UPD performance crank pulley and UPD adjustable rear suspension with ride height adjustment.
CL55 UPD Cold Air Boost kit, UPD 3000 stall converter, UPD 77mm SC clutched pulley and beltwrap kit, Custom long tubes, UPD crank pulley , UPD suspension kit, UPD SC pulley, Aux. HE, Trunk tank w/rule 2000 pump, Mezeire pump, UPD 5pc idler set, Aluminum rotor hats.
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Symptoms:
Hard start when hot (even if just hot sitting in sun) - Car would turn over for 5-6 seconds before firing
On some starts, Idle would be very low 400 - 500 RPM for a few seconds before coming up to normal.
Based on all the treads, I did the CPS- All problems resolved. I am glad I did not wait for it to die.
Symptoms:
Hard start when hot (even if just hot sitting in sun) - Car would turn over for 5-6 seconds before firing
On some starts, Idle would be very low 400 - 500 RPM for a few seconds before coming up to normal.
Based on all the treads, I did the CPS- All problems resolved. I am glad I did not wait for it to die.

Took her to a local repair shop and mechanic said he couldn't do it due to starter immobilizer kicking in if CPS removed.
Since I've had part and tools ready I've decided to do it myself before work; 45 mins, $400 saved!
Car runs noticeably smoother, rough shifting is GONE.
Thanks again for the pics.
The Best of Mercedes & AMG
10 Days later Murphy decided to drop by and curse my wifes 2004 S430. She called me that her car would not turn over...I told here to wait and try again to make it home...Bought another CPS. This one although visible and with more approach sapace was a little trighter around the actual sensor. There was some kind of metal plate around the perimeter of the sensor which made it hard to maneuver around...but that plate saved me once from loosing the screw once or twice. This time I had to use and antenna magnet to get that screw out (while the sensor was stil in there). you see I try to loosen the screw first just over a 1/4 inch and then pull up the sensor then loosen the screw all the way then pull out the sensor with the screw still in the sensor but for some reason I almost lost it. Soooo.....when putting the CPS back in this time I could not use the Twist -tie trick because the metal plate would not give me enought room to pull the Twist-tie out afterwards. Sooo, to make a long story short I held the CPS with the screw in it with the socket extention but no rachet handel and hand tightened it. The rest is history....Phew!!!
Last night I finally threw a CEL after trouble starting and read P0335 "Crankshaft Sensor A Circuit Malfunction" w/OBD II. Searched this board and found these instructions. Not wanting to be down Labor Day Weekend, I picked up sensor at dealer this morning and an E8 at Autozone. Replaced the CPS this afternoon and car is running its best since I added TB and injectors a few months ago.
Thanks for posting tips for rookies like me. Saves alot of research time when things like tools needed, sensor location etc...are shared by senior owners.
One piece of advice, avoid dealer if you can. I was expecting $85 range but at Mercedes North Houston the cost of the CPS and a screw came to ~$210. Had I known this beforehand, I would have let car sit while I ordered it online.
Probably the only time I wished for smaller longer forearms and I am an average size guy
Now let's just hope I can get my fat hand down there to undo the connector when my sensor shows up.
Thanks BBBSS and everyone for this posting. I replaced the CPS last year with BBBSS' help on the E55 then shortly after on the ML320. The E55 is still running good. However, the ML320 is starting to have hard start ... appears to be the same symptom but no error code ... yet. I took the CPS back to AutoZone and got a free replacement but the problem is still there. Could there be something else that causing it? Any comments would be greatly appreciated.
6/10/2014 - Updates: I finally fixed the hard start problem by replacing the fuel pump & filter.
Last edited by vinnienle; Jun 10, 2014 at 06:58 PM. Reason: Provide updates
Just a little clueless and not much of a wrench

Probably stupid questions, given it is a CRANK shaft sensor, but....
Just a little clueless and not much of a wrench

Probably stupid questions, given it is a CRANK shaft sensor, but....
The pics in the first post are gone away.
Do I need to take off the Air filter cover ?
Do I need some sort of special screw to put it back in ?
Anyone has other photos ?
Any help would be appreciated.
Thanks
If the airbox doesn't seem to want to come out don't get crazy, you don't want to break the tabs off or something like that. If it's really being a pain just pull the bolts out and take the top off the box, remove the filter and the bottom will come loose much more easily.
Last edited by BBBSS; May 2, 2013 at 08:56 PM.







