2005 C320 cranks strong but will not start? HELP, please!

 

The car was parked over night after a 240 miles trip yesterday, There is not a check engine light, but the scanner indicated code 335 = Crank Position Sensor. I erase it and still it won't start, check for fuel on the rail via the rail Shrader valve and fuel drip out, obviously is not under pressure or power as I am by myself (I really don't know how to check the fuel pump, I will try to find the proper fuse location and inspect during the day. I can not remember if it possible to hear a click or something from the tank/back seat area sending unit? This CPS and the AGM battery I had just installed in June 2017 and less then 2,500 miles ago, after the CPS I installed at 96K miles in Nov. 2014 and the AGM battery I had installed in July 2014 @ 94K. miles check badly. I had not had any electrical gremlins other than this up to now. Any Ideas or direction will be much appreciated.

 

Real Bosch CPS or Quick-E-Save Auto Parts?

 

The CPS came from Autozone, they listed a Bosch for $60.95 but did not have it in stock in either local store, so I went with their Brand which actually cost $54.95, it looked identical to the MB OE I remove, it came with a lifetime warranty. I Will try later today to test it, I am looking for info to test the CPS if I need be removed and replace it, and will also check for any fuel pressure issues, LOOKING FOR SPECS AND PROCEDURES SEQUENCE FOR THAT AS WELL. Thanks for your response!

 

Autozone = Quick-E-Save = Zip-E-Quick

If you have a current P0335 code, you have bad CPS.

CPS cuts off fuel, IIRC.

 

I have not been able to get the engine started, check engine light or codes. I support the importance of good OE or OEM parts, but I am not sure that MB OE CPS failures were any less for this generation MB engines that place it in such a hot forsaken location. 2 CPS failures in 2.5 years and little over 12K. miles? Just this past June when replacing it for the second time, the first back in Nov. 2014, I also did the valve covers gaskets/air breathers, spark plugs/cables, pulleys/belt, oil/filter, flush P/S and a few other preventive things since I had easy access that engine was clean before I started and after I had finished and most wires check & connections were clean with electric cleaner and lube with dielectric grease. A few people never had any problems with it, could there be another roots cause for its failure?


.

 

read above

 

After checking the CPS, MAF, fuel pressure and battery, I decided to rule it out and since it came with a warranty to just get and install a New one. Then I check for codes, zero, NONE then I tried 3-4 times and it would not start, then after 30 minutes the car roughly came to life and in seconds settle to a smooth idle, then once again check engine light came on, I keep it running at idle until it reached operating temperature, then shut it off and with a much better scanner again code "P0335 Sensor A Circuit", now it wont start again.

 

Either you keep getting mickey mouse CPS or the wiring is bad.

 

I have to agree with you, after testing the CPS = OK, I think it may be a bad wire or connector. I will test that wire tail tomorrow if nothing found I will replace it with an MB or Busch. By the way, after it sat for 4-5 hrs. it started, I let it idle and turn the A/C auto on to add the fan load and added engine ventilation this time it only idle for about 10 minutes and then cut off, No check engine light but a pending P0335 code I erase it and just a moment ago and 2hrs after it cut OFF, it started immediately. I turn it off and walk away until tomorrow.

 

Today the car started and it shows no codes, I check the battery and I was surprised when the battery was down to 11.4v. after I had slowly charge it to about 90% the day before, So I hook up the charger in auto mode and a couple hour later it said 12.4v. the voltmeter test confirmed that voltage, but I notice it still had not selected an amp charge rate 2, 8 or 12 amps. as it normally does, so I check the charge percentages and it was only 11%. That leads me to think that the problem may be a parasitic draw. The discharged battery(s) = Group BCI 49-H8 AGM 1000CA, 900CCA, 95amp hour, 160 reserve minutes are good for a long while when new and fully charged and My few but long drives per week keep it somewhat charge, but not enough amps may be setting the P0335 code and the problem starting the car.
CODE p0335=
faulty CPS
CPS harness is open or shorted
CPS poor electric circuit connection
the signal plate may be damaged
the starter may be faulty
starter system circuit
dead or weak battery

I guess I'll be testing for a parasitic drain next. My car is a 2005 but read about issues with the seat modules mostly in 2001-2004, maybe I just ran out of borrowed time. I disconnected the negative wire and hope to be able to charge the battery to 100% overnight
Any advice is welcome, Thanks!

 

Hope OP will come back and post what this was

 

MacVid, it appears as if you are the only person that reads my boring long winded (sorry about that) posts. LOL I guess there are so many on the W203 since 2001 and other similar MB car issues, it may no longer be interesting & most figure if you want an answer and have unlimited time, you can find it, "Fair Enough" but far from my reality and confidence level. IMHO it defeats the main purpose of open forums. In any case, I charged the battery to 100% and after shooting all systems off and closing doors, trunk etc,... waiting 30 minutes I had already removed the NEGATIVE cable to charge the battery overnight and using a small piece of wood against the dome light pin to hold it push IN on the pin on the door jam and turned the door latch to simulate it close. I allowed 45 min. for all systems to go to sleep, then with the ohmmeter still between the negative cable terminal and negative post found a 6 or 7 amp draw, way above the .01 - .05 amp. that is the norm for most modern cars. I check all the fuses under the hood and a few cause it to drop to as low as 3.6 amps. When I started with the fuses on the dash, a couple dropped the draw, I was tempted to just unplug the seat controller units but there are at least 4 or 5 plugs just under the driver seat, and I Am not sure what else or what any of them does. I noted the fuses that made a difference and it must have gotten blown away and have yet to work my way to the trunk panel other than the 6-7 amp original amp load I may be confused about the drops having read & watch so much about this problem in the past 3 days spare time and I got fed-up of messing with this PITA for today.

 

For what it's worth, I'm reading your posts too. Keep us updated!

 

How did it start and run with fully charged battery?

That's the important question.

 

On Sunday the car started fine several times and no more codes, but I have yet to find what ever is that is wrong with it and I don't trust it to drive. Monday-Tuesday, I charged the battery on its lowest setting, 2 amps overnight until it reached an indicated 100% charge and 12.8v. on the dial of my now older "Schumacher" charger, and 12.5v. with my My "Craftsman" voltmeter, 12.7v. with My brothers Professional "Fluke" voltmeter (?) then not trusting any of them, I removed the battery and the alternator and took them to a shop to have them bench tested. They fully tested the battery 2x and the alternator 5x, both checked out fine. I reinstalled them but did not connect the battery. Today I had other things to take care off and hopefully, I will see where I am tomorrow Thursday.

 

Any update?

 

Hey, OneAdam12. Unfortunately no, I just haven't had the time. I Wish I still had a garage to work in late at night when I usually could!

 

The car had sat for 5 weeks, while I took care of other things. In the meantime, I had ordered a Bosch CPS and before I installed it, I compared it to The old MB OE, I had replaced in 2014 and the AutoZone-Duralast, I had replaced under warranty and tested several times recently. The 3 bench tests; Resistance, Continuity, and Voltage were very similar between all three, however, I did notice a slight difference in the plastic surrounding the metal end of the Duralast CPS it was different from the Old MB OE and the NEW Bosch CPS. Also when I inserted the new Bosch it was very snug going in the hole. The Car started fine but was only putting out 11.9v. volts to the battery under load. So I took it to an Independent Repair shop with the MB STAR diagnostics and over 35 years experience. They performed complete scan test of all control modules throughout the car, clearing and resetting all, check starting & charging systems, check various grounds & key-off battery drain (now magically 0.40 mAmps.) and driving it home overnight several times for sign of reliability or faults, he said "nothing found", Somehow the charging system is NOW putting 13.9v.-14.1v., He said It appeared I had already fixed the problem and that he has had similar intermittent problems before, but they had being the usual culprits.... bad grounds or connections, the seat and overhead modules and bad or incompatible batteries, usually AGM, but right now, everything is working within specs and to drive it as much as possible and do nothing to it if something comes up, maybe he can trace it. I will be motoring On a Wing and a Prayer.


PS: I stop by AutoZone to get some service supplies for upcoming maintenance on my Mothers car, and the Manager ask me about my car saga and after I told him, He asked if I still had the Duralast CPS or the receipt? Wich I did have in my car, "he just gave me my money back" I had not even implied he should, That was very decent of him!