CPS - "Crankshaft Position Sensor" Discussion Thread
Moderator Alumni
Joined: Apr 2006
Posts: 3,255
Likes: 22
From: Seattle
w203 m112
Some neat Info I found from the XF Forums - Save some $$ on the CPS!
http://www.crossfireforum.org/forum/...tml#post605626
Originally Posted by LantanaTX
My CPS died last night. I went to O'Rieley's last night and picked up a new one. The one they sell is made by borg Warner and has a lifetime guarantee for $54. The electrode on the end is different than the factory one. Since we know the factory ones will fail, I was glad to see this one is different and with the guarantee, I won't ever have to pay for another. I had recently also put one of these in the E500 I recently bought.
Super Moderator
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
To make sure that you don't have another bad CPS pour cold water over the CPS when the car is hot & see if it will start.
Check fuel pressure at the Schrader valve on the rail that connects all the injectors - it must be > 55psi or 3.8 bar while cranking.
Read codes with an OBDII scanner & post.
Good luck!
Check fuel pressure at the Schrader valve on the rail that connects all the injectors - it must be > 55psi or 3.8 bar while cranking.
Read codes with an OBDII scanner & post.
Good luck!
Newbie
Joined: May 2012
Posts: 1
Likes: 0
From: California
S430
CPS
My car was stoping suddenly and restarting and I replace the crank position sensor and the problem was solve the part cost me $58.00 at autozone and I paid a guy $65.00 to replace it. be careful of dealerships and autoshop they will charge you from $200 to $350 and its a 15 to 20 minute job they will rip you off. I found a great mechanic off craigslist went and bought the part and he put it on in 20 minutes now im back on the road running great!
Newbie
Joined: Oct 2009
Posts: 12
Likes: 0
From: Northford CT
C320 300E
cps, P0335
My C320 was cranking longer than normal sometimes to start and then finally quit (in traffic of course) for 5 minutes but gave me the engine light with a code of P0335.
Advance part for $60 looks just like the oem Bosch part and installed fine but you need the small #8 torque socket 1/4 inch drive with the 8" and 3"extensions plus a u joint and driver handle as stated in a previous post. Tape them together or they may disappear. Small hands to fit behind the tight cylinder head to firewall space helps!
Maybe Glyn Ruck, super moderator can explain but the Mercedes service CD says that the car has to be plugged into the star service pc after sensor replacement to adjust the ecu to the "new sensor".
I did not do that. Good to go for now!
Advance part for $60 looks just like the oem Bosch part and installed fine but you need the small #8 torque socket 1/4 inch drive with the 8" and 3"extensions plus a u joint and driver handle as stated in a previous post. Tape them together or they may disappear. Small hands to fit behind the tight cylinder head to firewall space helps!
Maybe Glyn Ruck, super moderator can explain but the Mercedes service CD says that the car has to be plugged into the star service pc after sensor replacement to adjust the ecu to the "new sensor".
I did not do that. Good to go for now!
Super Member
Joined: May 2009
Posts: 904
Likes: 22
From: Toronto, Ontario, Canada, eh!
2003 C230 Sports Coupe, Paprika Metallic Red, Auto, Pano, Leather
The DVD talks about using STAR to reset sensor "adaptation". A recalibration.
I'm thinking since there's a magnet at the tip of the CPS and it goes in at slightly different depth and over time it would get oil on it,.... so signal strength would vary.
My understanding is that the car can do the recalibration itself without STAR,... with the car in PARK, rev slowly up to 2500RPM in 2 minute (idle is 700RPM, so you're adding about 150RPM every 10 seconds,... very slowly!),.... then hold the rev at 2500RPM for 30 seconds; then drive,.... that should recalibrate the CPS.
If you had NO cps faults prior to change then no recalibration needed.
I'm thinking since there's a magnet at the tip of the CPS and it goes in at slightly different depth and over time it would get oil on it,.... so signal strength would vary.
My understanding is that the car can do the recalibration itself without STAR,... with the car in PARK, rev slowly up to 2500RPM in 2 minute (idle is 700RPM, so you're adding about 150RPM every 10 seconds,... very slowly!),.... then hold the rev at 2500RPM for 30 seconds; then drive,.... that should recalibrate the CPS.
If you had NO cps faults prior to change then no recalibration needed.
Last edited by SunnyRayToronto; Sep 14, 2012 at 02:50 AM.
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Senior Member
Joined: Mar 2003
Posts: 448
Likes: 4
From: San Antonio, TX
'11 SL550 - '08 ML350
I started having issues again with the engine being hard to start. So I decided to change the position sensor. Thanks for all the info found in this and a couple other threads, I knew just what I needed to do. Now just to help others who, like myself, are more visually oriented, here is a picture showing the crankshaft position sensor. I removed the MAF and elbow to get this view. Like others have said you can't see this from the top. The large hose is right over the top. From this pic you can see the orientation and that the hold down bolt is on the right side towards the fender. I used two 6" 1/4" extensions with a swivel in the middle. Note you have to go in from the right side of the engine. You do not try from the top. The sensor is not pointing up. It is leaning towards the fender.
Last edited by Wardsweb; Oct 21, 2012 at 11:46 AM.
Super Moderator
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
This is an M272 but the sensor position is the same for M112. You don't need to adapt the new sensor. The only time it is necessary is if for some confounded reason the ECU can't "see" it. I've never had that problem.
Also see the Wiki.
Also see the Wiki.
Junior Member
Joined: Nov 2012
Posts: 16
Likes: 0
From: Maryland, USA
2005 C240
OK, so here's my story.
About a week ago wife reported intermittent no-start events on 2005 C240.
I scanned car and found CPS sensor error. Replaced sensor.
During my DIY process, I broke the MAF bracket. Thread on that process can be found here: https://mbworld.org/forums/c-class-w203/469390-help-maf-clip-broken.html Replaced the MAF bracket and car was running fine for about a day.
Tonight, after a short 15 minute drive and then turning engine off and going in store, car would not start. Used long ratchet handle to poke/wiggle newly replaced CPS, and engine started right up.
Then, while driving back home, engine cut off while driving. Pulled over, put car in P, turned key off/on, car started right up. That happened 3 times before reaching house.
Here's my question: What is the likelihood that I got a bad replacement sensor? I've rechecked all my work/connections and all looks to be in good order.
If this was actually an EIS or Camshaft sensor issue, would I see an EIS or camshaft specific code or could a CPS code still be generated even though its actually an EIS or C(amshaft)PS instead of C(rankshaft)PS?
Anyone have experience with a faulty CPS wiring harness on a W203? I read that corrosion was building up on wiring harnesses of older gen 240's, but haven't seen any reference to this in the W203's.
About a week ago wife reported intermittent no-start events on 2005 C240.
I scanned car and found CPS sensor error. Replaced sensor.
During my DIY process, I broke the MAF bracket. Thread on that process can be found here: https://mbworld.org/forums/c-class-w203/469390-help-maf-clip-broken.html Replaced the MAF bracket and car was running fine for about a day.
Tonight, after a short 15 minute drive and then turning engine off and going in store, car would not start. Used long ratchet handle to poke/wiggle newly replaced CPS, and engine started right up.
Then, while driving back home, engine cut off while driving. Pulled over, put car in P, turned key off/on, car started right up. That happened 3 times before reaching house.
Here's my question: What is the likelihood that I got a bad replacement sensor? I've rechecked all my work/connections and all looks to be in good order.
If this was actually an EIS or Camshaft sensor issue, would I see an EIS or camshaft specific code or could a CPS code still be generated even though its actually an EIS or C(amshaft)PS instead of C(rankshaft)PS?
Anyone have experience with a faulty CPS wiring harness on a W203? I read that corrosion was building up on wiring harnesses of older gen 240's, but haven't seen any reference to this in the W203's.
MBWorld Fanatic!
Joined: Nov 2001
Posts: 5,851
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From: Huntington Beach, Ca.
'17 Jaguar XF
..... poke/wiggle newly replaced CPS, and engine started right up.Then, while driving back home, engine cut off while driving. Pulled over, put car in P, turned key off/on, car started right up. That happened 3 times before reaching house....Here's my question: What is the likelihood that I got a bad replacement sensor? I've rechecked all my work/connections and all looks to be in good order.....
Super Member
Joined: May 2009
Posts: 904
Likes: 22
From: Toronto, Ontario, Canada, eh!
2003 C230 Sports Coupe, Paprika Metallic Red, Auto, Pano, Leather
Did you plug in the electrical wire into the CPS plug correctly,.... Did you get the correct CPS, one CPS has one notch and the other has 2 notches for the CPS plug.
Did you do the CPS recalibration I posted about,....
Clear the codes, and use your OBD2 scantool to read code again if it stalls or non-start again,...
Last edited by SunnyRayToronto; Nov 6, 2012 at 09:14 PM.
Junior Member
Joined: Nov 2012
Posts: 16
Likes: 0
From: Maryland, USA
2005 C240
No, I did not. I will try this first.
The wife and I are sharing my car until I can get reliable results from the 240. It's pretty nasty out here, cold and wet. I'm going to try and dig back into the issue tomorrow and dedicate the weekend to it. I will post up more info when I get it.
Thank you very very much!
MBWorld Fanatic!
Joined: Nov 2001
Posts: 5,851
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From: Huntington Beach, Ca.
'17 Jaguar XF
Super Member
Joined: May 2009
Posts: 904
Likes: 22
From: Toronto, Ontario, Canada, eh!
2003 C230 Sports Coupe, Paprika Metallic Red, Auto, Pano, Leather
mleskovar is a long time and well respected contributor to these boards and a great resource for us DIYers. 
Personally, I've lost count of how many of mleskovar DIY thread and advice post I have followed over the years.But, I am a sucker for torquing to MB specs and one reason I think its important here is because the CPS measures magnetic signal based on distance to the teeth and gaps on the flywheel,... if the CPS is too low on torque then distance between CPS and flywheel would be greater than it should,... and the magnetic signal reported by the CPS will be a bit weaker,... like I said, I`m a sucker for torquing to specs. I`m sure you can get away with hand tightening to just about what feels right,... its a personal preference,.. but if I was taking it to a MB dealership or indy for service I would expect everything torqued to specs.
But do NOT torque even a hair over MB specs,.... CPS sits on an aluminum casing,... if you over-torque and ruin the threads on the casing,... your real troubles are just begining,...
Yes, different MB part numbers for one VS two notch. Make sure to use Genuine MB parts or at least MB OEM parts,... as, I recall MB CPS are AB-elektronik (Hella). Anything else is junk.
Junior Member
Joined: Nov 2012
Posts: 16
Likes: 0
From: Maryland, USA
2005 C240
SunnyRay Toronto, mleskovar,
Thanks a lot guys. I really appreciate it. Like I said, It's getting nasty outside here, but I will get back to the 240 as soon as I can.
Thanks for that info. I put some blue loctite on the bolt, I was hoping that would stop any backing out. I did crank it a little, because I felt like the linkage in the extensions was allowing too much slop. I'm going to pay good attention to the threads when I pull the bolt back out. I can't imaging trying to re-tap the casing.....
Also really good info. I was wondering if there were any specific manufacturers to look to in the event that this CPS is a dud. I got this one from Advance, and I forget who manufactured it.
Thanks again guys, you and this entire forum are life savers, deities even!
Thanks a lot guys. I really appreciate it. Like I said, It's getting nasty outside here, but I will get back to the 240 as soon as I can.
But do NOT torque even a hair over MB specs,.... CPS sits on an aluminum casing,... if you over-torque and ruin the threads on the casing,... your real troubles are just begining,...
Yes, different MB part numbers for one VS two notch. Make sure to use Genuine MB parts or at least MB OEM parts,... as, I recall MB CPS are AB-elektronik (Hella). Anything else is junk.
Thanks again guys, you and this entire forum are life savers, deities even!
Junior Member
Joined: Nov 2012
Posts: 16
Likes: 0
From: Maryland, USA
2005 C240
OK, so I got to mess around with it a little today. Still don't have weather to be able to tear it back down, but here's what I got.
I tried the calibration. I don't have a steady enough foot, so I wasn't able to keep a consistent RPM increase, but I tried both the 150 RPM @ 10 sec and the 100 RPM @ 6.6 sec calibration.
Between the multiple attempts to calibrate, the CEL went out. I thought, "success!"
So I drove it around town. Still died on me.
I tried another troubleshooting method I read on the forum - pouring water down the firewall near the CPS to cool it off. I was hesitant to pour cold water on a hot engine, and near electrical connections, but there were no chastising comments thrown up when this method was posted, so I gave it a try. Just to eliminate questions, I poured the water down the firewall, not actually on the engine.
Inconsistent results from the water-pouring test. Poured water after three different stall events - one water-pouring created immediate start on crank, the other two had no effect, engine did not turn over on crank with multiple tries.
Also, when I got back to the house I scanned it again. Only error thrown is "crankshaft position sensor A malfunction".
As soon as the weather breaks I will dig back in to her and inspect the sensor, harness, and bolt (bolt for thread wear or evidence of overtightening)
I tried the calibration. I don't have a steady enough foot, so I wasn't able to keep a consistent RPM increase, but I tried both the 150 RPM @ 10 sec and the 100 RPM @ 6.6 sec calibration.
Between the multiple attempts to calibrate, the CEL went out. I thought, "success!"
So I drove it around town. Still died on me.
I tried another troubleshooting method I read on the forum - pouring water down the firewall near the CPS to cool it off. I was hesitant to pour cold water on a hot engine, and near electrical connections, but there were no chastising comments thrown up when this method was posted, so I gave it a try. Just to eliminate questions, I poured the water down the firewall, not actually on the engine.
Inconsistent results from the water-pouring test. Poured water after three different stall events - one water-pouring created immediate start on crank, the other two had no effect, engine did not turn over on crank with multiple tries.
Also, when I got back to the house I scanned it again. Only error thrown is "crankshaft position sensor A malfunction".
As soon as the weather breaks I will dig back in to her and inspect the sensor, harness, and bolt (bolt for thread wear or evidence of overtightening)
Junior Member
Joined: Nov 2012
Posts: 16
Likes: 0
From: Maryland, USA
2005 C240
Success!!
So, the car is finally running well. Actually, it's running better than it did before the CPS issue (I think thanks to the MAF cleaning).
Here's what I did.
1. I went to Advance, got a new sensor. We'll call this, Sensor2 as apposed to the sensor I installed the first time, which we will call Sensor1.
2. Tore everything back apart and checked for any loose connections in the process - didn't find any.
What I did find, is that the first sensor I installed, Sensor1, had a large amount of corrosion on the magnet.
3. Compared Sensor1 to Sensor2. Sensor2 also had some corrosion, but not nearly as much as Sensor1.
4. Used 000 steel wool to polish the magnet on Sensor2 (should have taken pictures before and after, but I didn't. Oh well.)
5. Install Sensor2, put everything back together.
6. Remove boot from my foot and perform SunnyRayToronto's calibration using the 100 RPM @ 6.6 sec method (I had to remove my boot in order to be accurate enough with the throttle).
7. Drive happily with no problems for 3 days, and under all conceivable conditions.
I have attached a picture of Sensor1 and Sensor2. If anyone else performs this job, PLEASE inspect your new sensor for corrosion before installing.
FYI, I got both sensors from Advance, and both brands were BWD/Intermotor. Both had corrosion.
So, the car is finally running well. Actually, it's running better than it did before the CPS issue (I think thanks to the MAF cleaning).
Here's what I did.
1. I went to Advance, got a new sensor. We'll call this, Sensor2 as apposed to the sensor I installed the first time, which we will call Sensor1.
2. Tore everything back apart and checked for any loose connections in the process - didn't find any.
What I did find, is that the first sensor I installed, Sensor1, had a large amount of corrosion on the magnet.
3. Compared Sensor1 to Sensor2. Sensor2 also had some corrosion, but not nearly as much as Sensor1.
4. Used 000 steel wool to polish the magnet on Sensor2 (should have taken pictures before and after, but I didn't. Oh well.)
5. Install Sensor2, put everything back together.
6. Remove boot from my foot and perform SunnyRayToronto's calibration using the 100 RPM @ 6.6 sec method (I had to remove my boot in order to be accurate enough with the throttle).
7. Drive happily with no problems for 3 days, and under all conceivable conditions.
I have attached a picture of Sensor1 and Sensor2. If anyone else performs this job, PLEASE inspect your new sensor for corrosion before installing.
FYI, I got both sensors from Advance, and both brands were BWD/Intermotor. Both had corrosion.
Super Member
Joined: May 2009
Posts: 904
Likes: 22
From: Toronto, Ontario, Canada, eh!
2003 C230 Sports Coupe, Paprika Metallic Red, Auto, Pano, Leather
For comparison sake,... attached is a photo of my 10 year old original MB CPS that I replace last month,.... Notice, the magnetic tip is still shiny with no sign on corrosion after 10 years of usage.
Second photo show side shot of original MB CPS,... the dirt and corrosion looking thing on the plastic is actually gummy old oil. Notice beside the MB star is OEM AB-elektronik logo. This is the one notch CPS MB part# 003-153-28-28. Even the Hella CPS is really made by AB-elektronik,... the original MB CPS OEM.
Always use genuine MB or MB OEM parts,....
Second photo show side shot of original MB CPS,... the dirt and corrosion looking thing on the plastic is actually gummy old oil. Notice beside the MB star is OEM AB-elektronik logo. This is the one notch CPS MB part# 003-153-28-28. Even the Hella CPS is really made by AB-elektronik,... the original MB CPS OEM.
Always use genuine MB or MB OEM parts,....
Last edited by SunnyRayToronto; Nov 11, 2012 at 12:48 AM.
MBWorld Fanatic!
Joined: Jul 2011
Posts: 1,890
Likes: 6
From: Northeast PA-Poconos
2014 E350, 2006 C350 Sport(made it to 280k, loved it!), 1990 300E
CEL warning came up yesterday. I took it in to dealer to have them put a new left parking light bulb. They replaced a cam solenoid. Specifically a "Electrical Wiring Harness for Solenoid of Cam Shaft Adjustment Retrofit." This was a campaign from MBUSA that they performed for free. This was 2 weeks ago. Fast forward to today. Would this affect the CPS? Do I need star to read why I am getting CEL?
MBWorld Fanatic!
Joined: Nov 2001
Posts: 5,851
Likes: 196
From: Huntington Beach, Ca.
'17 Jaguar XF
Newbie
Joined: Aug 2012
Posts: 11
Likes: 0
C3
I unknowingly created a CPS post today. Here are the details so it can maybe help someone. But first *I* need help.
I have a '04 C320 and while driving home Thursday night the car lost all power. I got it to the side of the road and towed home the next day. Here are the symptoms.
Lost all powertrain, electric fine.
Crank, no start.
No error lights, no malfunctions
won't turn over
RPM needle doesn't budge
I rented an OBDII meter and it threw the P0335 code for the Crankshaft Position Sensor. I went and got a new one of these from the parts store and installed it from directions on this site. Same result. Cleared codes and tried again, same result.
Returned CPS thinking faulty, got another one from another dealer and installed. Same result.
At this point I'm concerned and confused. What do I do next? My nearest MB dealership is 60 miles away and I'm stuck without my primary car.
A STAR reset is suggested, I guess I'll try and get this done tonight/tomorrow.
I have a '04 C320 and while driving home Thursday night the car lost all power. I got it to the side of the road and towed home the next day. Here are the symptoms.
Lost all powertrain, electric fine.
Crank, no start.
No error lights, no malfunctions
won't turn over
RPM needle doesn't budge
I rented an OBDII meter and it threw the P0335 code for the Crankshaft Position Sensor. I went and got a new one of these from the parts store and installed it from directions on this site. Same result. Cleared codes and tried again, same result.
Returned CPS thinking faulty, got another one from another dealer and installed. Same result.
At this point I'm concerned and confused. What do I do next? My nearest MB dealership is 60 miles away and I'm stuck without my primary car.
A STAR reset is suggested, I guess I'll try and get this done tonight/tomorrow.
