2002 C240 stall, Crank but No Start - CrankShaft Position Sensor Problem?
06-21-2015, 08:01 PM
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Mercedes 2002 C240
2002 C240 stall, Crank but No Start - CrankShaft Position Sensor Problem?
Hey Guys,
I was hoping to get some help on figuring out what is going on with my 2002-C240. A couple of days back, while waiting for the light to go green, it just died. I was able to start it a after 40 minutes, but it died again right outside the mechanic shop.
When I tried to start it again I got a crank but no start. Now the mechanic took a day to figure out what's going on and he tells me I need to replace Ignition coil, Crankshaft position sensor (CPS) and all the spark plugs
Can anyone suggest me what to do here - should I get a second opinion or just get all these things replaced? My basic research here tells me that people who have run into this issues could solve it by replacing CPS only.
Really Appreciate the help
I was hoping to get some help on figuring out what is going on with my 2002-C240. A couple of days back, while waiting for the light to go green, it just died. I was able to start it a after 40 minutes, but it died again right outside the mechanic shop.
When I tried to start it again I got a crank but no start. Now the mechanic took a day to figure out what's going on and he tells me I need to replace Ignition coil, Crankshaft position sensor (CPS) and all the spark plugs
Can anyone suggest me what to do here - should I get a second opinion or just get all these things replaced? My basic research here tells me that people who have run into this issues could solve it by replacing CPS only.
Really Appreciate the help
06-23-2015, 02:55 AM
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I can't remember the maintenance recommendation on spark plugs but you may want to check on that as I doubt they are bad as the car uses 12 and I have never really heard of anyone having staling issues due to them. That said you may get a smother running engine. If the car has questionable fuel used in the past you may want to consider doing them but I would focus on the staling issue first.
Did the shop say why they wanted to replace an ignition coil? On the m112 engines they are not that common of an issue but I did have one go out around 200k and it did make the car run like crap but it still ran and wouldn't cause a stall. (he might have gotten a misfire on that cylinder or something though)
What I would do is replace the CPS and then see what issues are left. Clear all codes with a scan tool and see what CEL comes back or pending codes either immediately or after about a week.
The CPS is easy to do while I never did it on my c320 I did it on a fellow members c240 and besides being in a hard to get to location it only requires basic tools and 15-30 minutes of time. Also helps to have skinny arms and if you don't enlist the help of someone who does as even a 10 year old could do it as it is a connector and one screw holding it in. That said they do like to get stuck so sometimes a pair of long pillars can be helpful to twist it out.
Did the shop say why they wanted to replace an ignition coil? On the m112 engines they are not that common of an issue but I did have one go out around 200k and it did make the car run like crap but it still ran and wouldn't cause a stall. (he might have gotten a misfire on that cylinder or something though)
What I would do is replace the CPS and then see what issues are left. Clear all codes with a scan tool and see what CEL comes back or pending codes either immediately or after about a week.
The CPS is easy to do while I never did it on my c320 I did it on a fellow members c240 and besides being in a hard to get to location it only requires basic tools and 15-30 minutes of time. Also helps to have skinny arms and if you don't enlist the help of someone who does as even a 10 year old could do it as it is a connector and one screw holding it in. That said they do like to get stuck so sometimes a pair of long pillars can be helpful to twist it out.
Last edited by samaritrey; 06-23-2015 at 03:00 AM.
06-23-2015, 09:43 AM
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Mercedes 2002 C240
Hey samaritrey - Thanks for the inputs. I have ordered a CPS but I am still debating the spark plugs.
They said that 4 cylinder misfire at idle and it possibly because of spark plugs. Also, the car showed P2069 transmission ECU error so the shop thought it could be a mechanical problem in transmission which I would think is possibly just pointing to CPS.
For the ignition coil it was suggested as a preventive maintenance so I am not definitely not going to do it for now.
They said that 4 cylinder misfire at idle and it possibly because of spark plugs. Also, the car showed P2069 transmission ECU error so the shop thought it could be a mechanical problem in transmission which I would think is possibly just pointing to CPS.
For the ignition coil it was suggested as a preventive maintenance so I am not definitely not going to do it for now.
Last edited by abhinitb; 06-23-2015 at 09:50 AM.
06-24-2015, 07:09 PM
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Yeah get the CPS replaced and see what issues are left. If cylinder 4 is still having issues move ignition coil not the wires to another cylinder and see if issue moves. If so then you know the ignition coil is bad and a used OEM one can be found for cheap on ebay or buy a new OEM one if you budget allows. I would not recommend an aftermarket one.
As for transmission tcu code its hard to say what its problem is without a MB star system as the generic code readers don't usually do to well with the more in depth computer on our cars.
I would try to reset all computer codes and see what comes back.
As for transmission tcu code its hard to say what its problem is without a MB star system as the generic code readers don't usually do to well with the more in depth computer on our cars.
I would try to reset all computer codes and see what comes back.
Last edited by samaritrey; 06-24-2015 at 07:11 PM.
06-25-2015, 05:18 AM
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2003 c320 Sport Coupe
I had to replace the CPS on my car about 2 months ago. I didn't have any issues with the car stalling, but I did have to wait until the engine was cooled off before the car would start up. I think you may be right about the transmission ECU code being related to the CPS; I didn't get any codes thrown for it, but my car went into limp mode while I was on the way home from the local auto parts store, so I wouldn't be surprised to see some codes related to the transmission.
I don't know if the layout of the m112 e26 is different from the layout of the m112 e32 at all, or if you plan on replacing the sensor yourself, but if you do change it yourself, make sure to have at least 18" of socket extensions and a flex-joint. It's an easy job, but finding the actual sensor can be difficult, having the extensions and flex-joint will save you a lot of headache once you've found the sensor. If I remember correctly, using a 6" extension at an upward slanting angle at the CPS bolt, connected to the flex-joint, which was then connected to a 12" extension pointing straight up from the flex-joint worked best for me (the layout of the extensions and flex-joint was shaped similarly to a hockey stick if that makes any sense).
If after replacing the CPS you continue to get misfires on cylinder 4, I would definitely do as Samaritrey recommended and try swapping the cylinder 4 coil pack with an adjacent one before looking at replacing the spark plugs. I would think that with the dual-spark plugs these engines use, it would be pretty uncommon for two plugs to fail in the same cylinder without any signs of trouble in the other 5 cylinders. Just swapping the cylinder 4 coil pack with another one will be far easier than replacing the spark plugs on these engines anyway. Cylinder 4 should be the front-most drivers side cylinder.
I don't know if the layout of the m112 e26 is different from the layout of the m112 e32 at all, or if you plan on replacing the sensor yourself, but if you do change it yourself, make sure to have at least 18" of socket extensions and a flex-joint. It's an easy job, but finding the actual sensor can be difficult, having the extensions and flex-joint will save you a lot of headache once you've found the sensor. If I remember correctly, using a 6" extension at an upward slanting angle at the CPS bolt, connected to the flex-joint, which was then connected to a 12" extension pointing straight up from the flex-joint worked best for me (the layout of the extensions and flex-joint was shaped similarly to a hockey stick if that makes any sense).
If after replacing the CPS you continue to get misfires on cylinder 4, I would definitely do as Samaritrey recommended and try swapping the cylinder 4 coil pack with an adjacent one before looking at replacing the spark plugs. I would think that with the dual-spark plugs these engines use, it would be pretty uncommon for two plugs to fail in the same cylinder without any signs of trouble in the other 5 cylinders. Just swapping the cylinder 4 coil pack with another one will be far easier than replacing the spark plugs on these engines anyway. Cylinder 4 should be the front-most drivers side cylinder.
