Try this :
When it's cold, turn the key on for 5 seconds, then off DON'T TRY CRANKING
Do this 3 times, then go ahead and try a start.
If that scenario is consistent, then replace the fuel pump and filter.

 

Thanks ala_xfire for the suggestion.

disclosure: I am in Maryland, my son and the car are in California.
I called him and had him try.
first Try car did not crank the 4th time after 3 cycle of turning the key on.
he disconnected the battery for 2 mins then
again 3 time the key on all the way to second position (no cranck) and the 4th time it did not crank.
one more negative dsconnect for a couple of mins and this time we try to turn on the car regularly, it started the second try.


Salvo

 

camassusa, You did not mention if you have checked under the styrofoam in the trunk for water? Have you scanned the car for DTC with a good scan tool that goes beyond OBD II and into the Mercedes codes?
There are probably a lot of old codes and many stored code. Clear them all. Drive the car until the problem resurfaces and then scan it again for codes.

 

Thanks zip439 for your feedback!

we have disconnected the battery 10th of times since we got the remanufactured PCM in dicember last year, since the car at some point almost daily stop cranking.
I have checked for water both driver and passenger floor and it was dry. I have not checked the trunk, will do. The engine light is not on, my basic code reades says no errors.
The smog check is past due and my son plan to drive it for say 200 miles and hope to get the smog check done. I also hope that after say the 200 miles a code may come up and help figure.
My local authorized mercedes shop was asking $250 per hour to check the code and set them properly if necessary (caviat they said assuming our tool are compatible..), i have delayed it since
.1 trying to make sure nothing else obvious may be the cause
.2 if the battery has been disconnected some/all codes may have been resetted

Thanks
Salvo

 

There is a pulse module in the starting circuit it could be faulty, a corrosive connection near the starter, there is a ground under the car on the drivers side that connects the frame and engine; a multitude of possibilities. It could be a bad crank position sensor if you did not use a Bosch as a replacement. You can download the service manual from this forum; thank you to onehundred80 Click service manual
$250 for a scan is too much. You can purchase an icarsoft MB II or a Foxwell nt530 with Mercedes software for under $200. Both are just for Mercedes and work well on the Crossfire; Just manually enter the car as a SLK 320 or for a little bit more you could purchase a Launchtech scanner that will work on most cars domestic and European.
Water in the lower trunk area is a sure sign of SKREEM problems. Use the search box in the upper right corner of the forum and search water in trunk. For about $50 you can get a fuel pressure gauge and the fittings from Needswings ( that is what ala-xfire was exploring)

 

Not SKREEM problems. Locking, lighting problems etc for sure.

 

Thanks for the suggestions.
I have asked my son to look in the trunk, i have sent pics to him found in that beautiful link you sent!

zip439 can you please elaborate more on why it may be the crank position sensor? It is my understand that the most common symptom when the crank sensor fails are that car starts when it is cold yet it may not when hot. this was also my experience before replacing it, Also i remember i was able to crank for several seconds, at will. now the cranking just stop after 1 second or less then at some point it does not crank at all.

I will read more about the scanner. i can see they are available on amazon. the Foxwell nt530 goes for about $170
and allows to add other cars software for $60.
I am debating If It is better buying the scanner or going to the Mercedes shop at some point. If i buy i may be able to read the codes yet if some of the setting need to be changed (remember i got a re-manufactured one )
I may not be able to and would need to go back to them anyway

Thanks!
Salvo

 

If the CPS, Crank position sensor, is something other than Bosch it has been found through experience that it often fails prematurely: Thus it may be the cause of your starting problems. You should pull it out and check to see if it is something other than a Bosch. Get a Bosch if it isn't.
ala-xfire was thinking you had low fuel pressure. He thought by running the fuel pump three times before starting it would build pressure in the fuel rail up at the engine. The fuel pump does not run at the second auxilary position at the key. You must turn the key to the third position were all the lights on the dash turn on to run the fuel pump. It would be good to be certain that third position is the one your son used when he attempted the fuel pressure build up and not just the auxiliary second position on the key. There is a check valve/regulator in the fuel filter, or the pump itself may be weak. They are located just forward of the right rear wheel under a plastic shield.
The water in the trunk can cause electrical problems and lead to expensive repairs if not corrected early. As mentioned, the air pump that also creates vacuum to lock/unlock the doors and a few other electric components are located there. Water cause electrical problems and possibly is causing the car to think someone is tampering with the car, so the anti theft device is activating and thus the SKREEM is doing what it is suppose to do and preventing the car from starting. Probably the easiest way to check for water back there is to get under the rear of the car on the passenger side. You probably will have to raise the car some to see what you are doing. There are two rubber plugs about one inch in diameter and they are covered with undercoating. The plug are aft of the axle. Use a small pocket knife or an ice pick and make a hole in the plug nearest to the exhaust pipe (there is nothing above it to damage). Twist the ice pick or knife a little and see if there is water leaking out.
Using the search box or searching the threads in the link I gave you will give more detail on anything I have said above, and be certain to check out the starting issues in the service manual it will step by step lay out how to check the starting system and the pulse module. The other common starting problem area is the RCM, relay control module. They have several contacts that get burned contacts and start causing starting problems. Look up RCM in the search box. There is a member in the forum that repairs your RCM for about $40 . Many of us keep a spare RCM in the glove box or trunk as it is a common failure.
If you choose to get the car scanned, use an independent garage that specializes in European automobiles, not a Mercedes dealer and certainly NOT a Chrysler dealer.

Generally buying parts for these cars is best done online from Mercedes or independent parts dealers who will get you the correct part. FCP Eur is just one of several. The parts sold at Advance auto, Auto Zone etc. are cheap china made and can lead to trouble. There are plenty who disagree; Take it for what you paid for it, but that is my advice.

 

Sir, i really appretiate all your inputs!

I should fly to california in a couple of months or so and join my son for a week or so.
Once there i will check on the crank sensor, i remember it was a pain to replace it, and if it is not a bosh, we will replace it. From here in MD i can only ask my son to do the straight forward checks.

I mention turning the key to the second position yet i think i asked to turn all the way before cranking. I think so because we were video conferencing yet will double check with him. The fact that when we did this the 4th try (the one he did try to crank) the car refused to crank seems to be an interesting clue yet difficult to decifer. It seems like the ?pcm? is getting a signal that something is wrong and disabling the crank.
I think we can exclude the engine starter motor and solenoid since i have verified that once the car starts i can restarts as many time as i want; i have tryied 4-5-6 times in a row. This also, i think, seems to tell us that the fuel pump should be ok. Unless the fuel pressure is still there from the previous start?

Glad you mention to check the trunk leak from the bottom side rather then from the trunk itself. At some point in the past i was trying to check the electonic in the trunk and it was not obvious to me how to access it.
I think your point that the anti theft tow sensor could be damaged is very interesting. I will also ask my son to verify if the allarm is working. May be the car is sensing something when it stop cranking but the siren is not working.

I appreciate you taking the time to point out not to take the car to neither MB nor FCA dealers. In my life i have always avoid dealers as much as possible. in my experience they not rarelly replace working parts for fun and charge you plenty :-)

Thanks!
Salvo

 

Forgot to mention I have replaced the RCM (relay control module) and the problem persist.

Thanks!
Salvo

 

I now have a problem the car dies and won't crank. cools down and starts. dies again soon and starts when cools down again. please help.

 

I am not an expert, yet those sintoms match a crank sensor failure. I had this issue and fix it replacing the sensor. based on other contribution the suggestion is to use bosh part

 

correction: in my case the crank always worked even when the car was hot. the car will not start yet it will crank. sorry for the confusion

 

That is what I also think.

 

First guess is to replace the Crank Position sensor, you are describing what has been proven to be a "heat sensitive" CPS.
MY Graphite did the same thing around 80,000 miles, but it happens anywhere from 10,000 to 150,000.

Make sure you get the OEM Bosh part, go ahead, but one at Autozone, just know that you will probably still struggle with the car if you do so.

 

camassusa, a HUGE help would be for the son to join here so things can come to us 1st hand. Is he a member and can he get in here so the ppl who are helping can know nothing got lost in a translation?


.

 

I just put in a new BOSCH CPS. The car still dies then won't crank till it sits for some time.

 

we verified that the keys were turned all the way (position3) right before cranking, hold for 5 seconds and the process was repeated 3 times. after that the car did not crank. we tried this twice.
He did try to access from the trunk the electronic. could not. We will look for possible you tube video.
the manual seems to simplify the process.


He did remove from the botton rear passenger side of the car the "cover", we saw two rubber plugs (video conference), he did stick a skrew driver through both and there was no leak, the skew driver went through a good couple of inches or more.
We tested the panic button. the light flashes yet no sound from the siren . he remember that in the past (by mistake) he did hit the panic button and the siren went off.
We played with the tow-away alarm in the consol. (the electonic of this switch is in the trunk and it is part of the allarm system) we saw the button flashing as expected when pushed the upper portion of the switch. we tried to start the car after
doing this and it felt differntly. the car stall the first try, started the second time, stall the third time and then no more crank. We will repeate this process (playing with this switch before starting the car) and see if this was just a one time affair.

Daniel my son is 19, and his priority are friends/college/girls and not necessarily in this order.

Thanks!
Salvo

 

Hi aschrager, check this crossfireforum post.
https://www.crossfireforum.org/forum...rol-module.pdf

 

Anyone tried the outrageous and had the error codes read? There is no point in having a car that can sometimes tell you your problem instead of guessing and throwing money at the car.