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HOW TO: R/R Crankshaft Position Sensor M113 (PHOTOS)

Symptoms: I was driving my car on a hot day and all of the sudden while stopped at a light, the engine died and would not restart. Each time I turned the key, this is what would happen:

M113 With CPS Unplugged - YouTube

After about 10 minutes the car would restart and drive but would shortly die again. There were no warning lights or indications that this was about to happen, until the car suddenly died.

From posting on this website and searching various other sources, it seemed clear that my problem was a faulty Crankshaft Position Sensor (CPS). I replaced mine with a non-OEM part (will replace with Bosch in a few months) that I bought off the shelf from Discount Auto, but can be found at Autozone, etc. Here are the steps for replacement....

Tools Needed:
1/4" ratchet
12" worth of 1/4" extensions (I used 2x6")
Thin screwdriver or similar (to align CPS with bolt hole)
Magnet wand (trust me, just get one....)
E8 Torx 1/4" bit
Flashlight
New CPS
Tape (Recommended)
IMG_0454.jpg

Starting point. The CPS is just underneath the engine cover (which I later removed) in this area.
IMG_0424.jpg

Here you can see the CPS illuminated by my flashlight. Note that the back of the car is to the right of the photo.
IMG_0429.jpg

Here is another view. Sorry the photo is rotated, it does it automatically for some reason. The CPS is visible in the center, the rear of the car is towards the top of the photo
IMG_0426.jpg

You must first unsnap the connector going to the CPS. It was not difficult to do, but be careful as there is a heat shield under there somewhere that you can see from this picture has already scratched my hand up :crybaby2:

IMG_0430.jpg

Now you can see what the actual CPS looks like with no connector attached. The torx bolt is at the bottom (to the right in the photo, towards the ground)
IMG_0431.jpg

New CPS with connector, for reference
IMG_0433.jpg

Now you need the ratchet with 12" of extension (but NO MORE) and the flashlight to find the bolt
IMG_0435.jpg

Way down there. It's not that difficult to reach or find though, with the 12" extension.
IMG_0436.jpg

The bolt did fall into the little metal lip just below the CPS, and I had to drive another car to the parts store to get the magnet wand. JUST GET THE WAND, it would have turned this into a 15 minute job, but instead took an hour because I had to get that wand.

With the CPS removed
IMG_0438.jpg

Continued in next post
 

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Again, the photo is rotated to the left, but you can see me retrieving the bolt with the magnetic wand
IMG_0440.jpg
IMG_0441.jpg

Old and new
IMG_0443.jpg

I used a screwdriver with a skinny end to align the CPS with the bolt hole
IMG_0444.jpg

Aligned
IMG_0446.jpg

To prevent the bolt from slipping off of the bit, which WILL happen, I used some automotive trim tape to lightly secure it on and it came right off with a little tug once it was tight
IMG_0442.jpg

Reconnect the wire and you are done!
IMG_0448.jpg

I have driven the car in 90+ heat the last two days and it shows no symptoms of stalling anymore. Also, before the CPS went, there were NO symptoms. All of the sudden the car just died, and even died while moving at 40mph. BUY THIS PART and keep it handy. You won't know it is bad until you are stranded on the side of the road.

PS My car is a 2002 with 62k miles

Hope this helps someone!
 

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had my crank sensor stall engine in rush hour yesterday and it was a hat day here in the 90F.
poured water all over the sensor and it started long enough to get off the highway.
purchased a new unit and off I go ..FYI @ 58,000 miles.
excellent post with pictures !
 

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Great write up. Got the CS changed in my E55 in less than ten minutes following your write up. :beerchugr:
 

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poured water all over the sensor and it started long enough to get off the highway.
Great, you read and followed the directions. I'm glad we were able to help otherwise it would have driven you crazy trying to figure out what was actually going on with your car at 58K miles.

Please see additional CPS R&R thoughts.
 

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Ok, to bring a great thread back to life!

My wife went to get her car inspected and was told the crankshaft sensor was bad and needed to be replaced.

After reading this thread I'm confident I can replace it. However.....

How do you reset the check engine light and the computer to show that the sensor has been replaced?
 

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How do you reset the check engine light and the computer to show that the sensor has been replaced?
With most CPS problems we are not given any notification such as a CEL but if that's the case you will probably need to take your car to an Independent Technician or a MB Dealer and have them connect your 38 PIN connector to a SDS (STAR Diagnostic System) in order to have the DTC (Diagnostic Trouble Code) erased = $50-$100.00.
 

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Discussion Starter #11
Forgot about this thread! I did not get a CEL or any other symptoms before my CPS died. I think if yours was "bad" you would know just from the car dying. I'm not aware of any obvious symptoms of a dying CPS, other than the car simply stalling.
 

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Just wanted to say thank you to "Board57796" for posting this VERY thorough write-up on this...
Everything went exactly as diagrammed out, and other than having to figure out how to get my big hand to contort just the right way to get things going, a pretty easy job..

Using an extension magnet on the removed bolt worked perfect, and taping the bolt into the socket to get it started was the ticket too...

I also used another 1" piece of masking tape to tape the bolt/socket combo to the new CPS unit itself, (with the bolt in the mounting tab of course) and then slid the whole thing into place.
I couldn't fully seat the CPS that way, but got it started sliding into the hole about half way, and I think it helped to avoid knocking any dirt or anything into the hole as well... Maybe that'll be helpful to someone else along the way too....

Regardless, thanks again for these great instructions...

Barry
 
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