'07 CLS 550 crank but won't start and is not the Crank Shaft Position Sensor
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From: CA
2007 CLS 550 and some other MBZ
'07 CLS 550 crank but won't start and is not the Crank Shaft Position Sensor
I didn't get any replies over at the 550 forum, so I am posting here to see if anyone has any idea.
OK, so last Sunday I went to start the car after parking at the mall for 2 hrs. and it would crank and crank but wouldn't start. 5 mins later I gave it another try and it fired right up. So, I thought to myself it must be the Crank Shaft Position Sensor as my car has 48,000 miles on it and has never been changed. I took it to my mechanic and he thought it was the CPS also, so I had he changed it out on Thursday. Everything was fine until today it did the same thing!!! This time though the crank didn't sound as strong as the first time it happened. So, I waited a few minutes and gave it another try and it fired right up! BTW, I already took it to a battery specialty place and they checked my battery and they said it's still very strong. What could it be then if it's not the CPS??? Anyone had the same problem before? Any input is very much appreciated.
OK, so last Sunday I went to start the car after parking at the mall for 2 hrs. and it would crank and crank but wouldn't start. 5 mins later I gave it another try and it fired right up. So, I thought to myself it must be the Crank Shaft Position Sensor as my car has 48,000 miles on it and has never been changed. I took it to my mechanic and he thought it was the CPS also, so I had he changed it out on Thursday. Everything was fine until today it did the same thing!!! This time though the crank didn't sound as strong as the first time it happened. So, I waited a few minutes and gave it another try and it fired right up! BTW, I already took it to a battery specialty place and they checked my battery and they said it's still very strong. What could it be then if it's not the CPS??? Anyone had the same problem before? Any input is very much appreciated.
Last edited by mbenz1; May 26, 2014 at 04:25 PM.
Thread Starter
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From: CA
2007 CLS 550 and some other MBZ
This might be a stupid question but how do you get to under the back seat? I don't see any openings for access, may be I am just looking at the wrong place.
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CLS 55 AMG E500 ML320
There is a hole in the carpet right at the bottom edge of the seat cushion. Put your finger in and push the spring clip while pulling up on the edge of the seat. The other clip toward the center console just pulls straight out, (hard). You'll see.
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From: CA
2007 CLS 550 and some other MBZ
Thanks. I took it to a new shop today and he thinks is the coding on the car that is causing the problem. I will report back on Friday after he plugs it into the computer.
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2002 C32AMG
If the car doesn't have an aftermarket tune the coding is not the problem. The fact your "mech" thinks it is makes me question his competence.
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From: DownEast Maine
CLS 55 AMG E500 ML320
Also check the fuel pump relay connection for overheating. Computers can be useful, but when it comes right down to it, you need fuel, spark, and compression to light a fire in it-----just like 100 years ago.
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Thread Starter
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From: CA
2007 CLS 550 and some other MBZ
So, the tech thinks it could be the battery as I have never changed that out ever since I bought the car, so it has been 7.5 yrs and he also tested the voltage and said it was a little low. New battery in and tonight it happened again.... 
I tried taking the rear seat out but got stuck after popping the clip close to the door. So, to release the side close to the center I just yank it out? It seems pretty tight and I don't want to break anything.....
I tried taking the rear seat out but got stuck after popping the clip close to the door. So, to release the side close to the center I just yank it out? It seems pretty tight and I don't want to break anything.....
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MBWorld Fanatic!
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From: DownEast Maine
CLS 55 AMG E500 ML320
It won't break. Put a tiny smear of grease on it to make it easier next time.
Pull it straight up, you can bend it if you pull it out crooked enough, no big deal, bend it back.
Pull it straight up, you can bend it if you pull it out crooked enough, no big deal, bend it back.
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From: CA
2007 CLS 550 and some other MBZ
Just spent over an hour with my tech and he checked to see if there were any fault codes and only found some random codes that he thought had nothing to do with my problem. I remember for the past few months the car would tell me a few "Key batteries low" and even though I changed them out to new ones it would still tell me that once in a while. Once in a blue moon it wouldn't detect the key, so now I am keeping my fingers crossed that it is the key that's giving me the problem. This is my second day using the new key so hopefully the problem won't come back.
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2007 CLS 550 and some other MBZ
It happened again!!!! I am beyond frustrated right now. Well, no choice but to take it in to the dealer in the next few weeks and hopefully it will happen at that time. I was there earlier and talked to a tech and he told me there's problem with the ME on the CLS? He was busy so didn't get into details about what model years are having the problem. I am now keeping my fingers crossed that it's the ME as the warranty is 8 years and I am only 2 months away from that!!!
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From: CA
2007 CLS 550 and some other MBZ
Well, I changed out the fuel pump relay myself right after the CPS and I got it from the dealer, so that one should be good. I am wondering if the CPS from the dealer could be defective. I asked my tech about that but he said if it's any of the 2 then I would get fault codes but I got only random ones like "Chip Card Faulty" and he said that's the first time he has seen that one.
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From: CA
2007 CLS 550 and some other MBZ
I have no idea. I am kinda busy these days so won't be able to take it in until later. I will report back once they find out what exactly is causing the problem.
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CLS55
I've been having a similar issue with my cls55, it randomly has a long crank/start but it eventually turns over. I'm still unsure what is causing this, but I'll be checking with the dealer tech tomorrow. Have you noticed any fuel smell coming from the back (outside of the car) after shutting down?
Thread Starter
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From: CA
2007 CLS 550 and some other MBZ
I've been having a similar issue with my cls55, it randomly has a long crank/start but it eventually turns over. I'm still unsure what is causing this, but I'll be checking with the dealer tech tomorrow. Have you noticed any fuel smell coming from the back (outside of the car) after shutting down?
Thread Starter
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From: CA
2007 CLS 550 and some other MBZ
Thread Starter
Senior Member
Joined: Jun 2006
Posts: 264
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From: CA
2007 CLS 550 and some other MBZ
Thanks, but did your car throw a code when the sensor was having problem? My car has been at the dealer for 2 days now and they still don't know what is causing it....
