TruTaing

Some neat Info I found from the XF Forums - Save some $$ on the CPS!

http://www.crossfireforum.org/forum/...tml#post605626

mleskovar

Thanks! Good find!

tdinh2012

i replace the new cps on c240 but the same poblem when it hot the car it won't start i have to wait 1 or 2 hours to restart and it work need help

Glyn M Ruck

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!

pastorwilkerson

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!

cats320

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!

contact148

no you dont need to code it with star

my manual said the same as yours

SunnyRayToronto

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.

Wardsweb

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.

Glyn M Ruck

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.

Rgray107918

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.

mleskovar

The chances are higher that something is wrong with the wiring or connector.

SunnyRayToronto

Did you torque the CPS to the proper torque,..... (8Nm for m271 & 722.6, I would expect something similar for your).

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,...

Rgray107918

I don't have a torque wrench, but I could get a hold of one. With the flex joints in the ratchet extensions, should I still stick in the 8Nm range or go i hair over to account for flex and pivot points?

The original and replacement both only had one notch - they looked pretty identical. Hence the one notch, I'm pretty sure I plugged it in correctly, but I am starting to wonder if I got a really good tight snug connection. It's on the list to check. Thanks for the info about the two different CPS's though. I'm assuming different P/N between the two?

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!

mleskovar

Not needed. Not critical. Tight enough so it won't vibrate out is ok. Pull the insulation/boot back if there's any there so you can inspect the plug and wires going into it.

SunnyRayToronto

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.

Rgray107918

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!

Rgray107918

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)

Rgray107918

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.

SunnyRayToronto

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,....

kluvsbenz

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?

mleskovar

AFAIK a bad CPS won't give you a CEL. You can diagnose CEL with any OBD II tester. Many auto parts stores will let you use one for free.

cyberpvnk

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.