CPS problem/story help
#1
MBWorld Fanatic!
Thread Starter
CPS problem/story help
So driving back from a date last night...and i felt that the gas wasnt responding anymore. i thought it was weird. then car started to sputter. noticed rough idle.
it died on me at every stop light. somehow when i waited a bit and started again, it was able to roll to her house before kicking the can.
had to get the car towed across a two cities to get home. and todays presidents day so i no go with the dealer. from what i read on the threads, this sound likes a CPS problem.
started it last night to experience rough idle and no gas response from the gas pedal. however, those with cps problems didnt sound like the car was completely unresponsive to the gas pedal so im worried that its more than that.
however, going to kragen to see if they have a cps part available. do you think this would suffice or should i be using a genuine mercedes part?
bheng
it died on me at every stop light. somehow when i waited a bit and started again, it was able to roll to her house before kicking the can.
had to get the car towed across a two cities to get home. and todays presidents day so i no go with the dealer. from what i read on the threads, this sound likes a CPS problem.
started it last night to experience rough idle and no gas response from the gas pedal. however, those with cps problems didnt sound like the car was completely unresponsive to the gas pedal so im worried that its more than that.
however, going to kragen to see if they have a cps part available. do you think this would suffice or should i be using a genuine mercedes part?
bheng
#2
My experience with bad CPS was as follow:
I was driving and the engine died all of a sudden. I stopped the car and attempted to start the car. The car would crank but did not start. i waited a few minutes. cranked again and it started. I let it idle for a few minutes and it died again all by itself. This repeated a few times and I finally called MB roadside assistant. It took the tech 20 minutes to replace the CPS.
I was driving and the engine died all of a sudden. I stopped the car and attempted to start the car. The car would crank but did not start. i waited a few minutes. cranked again and it started. I let it idle for a few minutes and it died again all by itself. This repeated a few times and I finally called MB roadside assistant. It took the tech 20 minutes to replace the CPS.
#3
MBWorld Fanatic!
Thread Starter
how much did it cost for the job, mis3?
i should have done that last night...but wasnt thinking how road side assistance would destroy me but the towing probably cost just as much.
-___- i should have just called road side assistance. LOL
i should have done that last night...but wasnt thinking how road side assistance would destroy me but the towing probably cost just as much.
-___- i should have just called road side assistance. LOL
#5
Super Member
Join Date: Jun 2011
Location: San Diego North County
Posts: 672
Likes: 0
Received 0 Likes
on
0 Posts
2015 E400 CAB, 2010 Jeep Compass, 2009 E350 Sedan
Call your Benz dealer my service department is open here you might want to check with yours to make sure there closed today if you have not already. Yes go with OEM parts if you can..
#6
MBWorld Fanatic!
Thread Starter
i hope they are open today. if not, i can wait for it tomorrow. i hope they have the part in stock so i dont have to wait a couple of days for it
i prefer oem but the clk is my dd
thanks for all the help guys! will post pics of the install to put up as well
UPDATE: so i called the parts department. the part costs 171. does that seem right?
i prefer oem but the clk is my dd
thanks for all the help guys! will post pics of the install to put up as well
UPDATE: so i called the parts department. the part costs 171. does that seem right?
Last edited by bheng; 02-20-2012 at 01:03 PM.
#7
Super Moderator
This does not sound typical of CPS only. Bad CPS usually causes poor or no starting. Most CPS failure is somewhat temperature dependent. They don't work when hot.
Standard roadside assistance fix is to pour a bottle of cold water over the thing to achieve a start & get the car home or to a dealership.
$25 to $55 at RMeuropean.
Standard roadside assistance fix is to pour a bottle of cold water over the thing to achieve a start & get the car home or to a dealership.
$25 to $55 at RMeuropean.
Trending Topics
#9
MBWorld Fanatic!
Thread Starter
This does not sound typical of CPS only. Bad CPS usually causes poor or no starting. Most CPS failure is somewhat temperature dependent. They don't work when hot.
Standard roadside assistance fix is to pour a bottle of cold water over the thing to achieve a start & get the car home or to a dealership.
$25 to $55 at RMeuropean.
Standard roadside assistance fix is to pour a bottle of cold water over the thing to achieve a start & get the car home or to a dealership.
$25 to $55 at RMeuropean.
I do notice the RPM meter bouncing up and down (slowly) when i tried to start it after i got the car into my garage. also, it does not respond to any gas pedal input.
does that sound like anything.
I think i will purchase an obdii reader today to get the codes and look them up online before i buy any unnecessary parts
Last edited by bheng; 02-20-2012 at 08:41 PM.
#10
I checked some online places and the Bosch one is $55. Not sure if this is OE.
If you can get it with this price, go for it. I changed mine in Dec-98, the roadside assistance guy said he was surprised that mine had not been changed already. Apparently there was a bad batch in 2003-2004 production cars. If this is true and yours was never changed, you may as well change it now to avoid further disruption.
He replaced it on the spot. The CPS is behind the engine and he had to sit on my engine to replace it!
If you can get it with this price, go for it. I changed mine in Dec-98, the roadside assistance guy said he was surprised that mine had not been changed already. Apparently there was a bad batch in 2003-2004 production cars. If this is true and yours was never changed, you may as well change it now to avoid further disruption.
He replaced it on the spot. The CPS is behind the engine and he had to sit on my engine to replace it!
Last edited by mis3; 02-20-2012 at 09:10 PM.
#11
Super Moderator
An M112 engine won't run if it does not know where TDC is - provided by CPS (other Benz engines like the M271 will run on the cam sensors). It will also not enable start if there is no signal from the CPS, temp sensor etc. Of course intermittent output from the CPS will cause erratic conditions. I would replace CPS as a matter of course but CPS trouble when hot usually makes a restart impossible until the CPS has cooled down.
Good luck
This is the EIS inductively energised key, handshake & start process. CKP is the CPS
Good luck
This is the EIS inductively energised key, handshake & start process. CKP is the CPS
#12
Super Moderator
You need to read those codes.
Once you have replaced the CPS - other things to check are:
TPS (Throttle pedal position sensor)
Fuel pressure at schrader valve on the rail is >3.8 bars WHILE CRANKING! (When last did the car have a fuel filter?)
MAF
Vacuum leaks.
Once you have replaced the CPS - other things to check are:
TPS (Throttle pedal position sensor)
Fuel pressure at schrader valve on the rail is >3.8 bars WHILE CRANKING! (When last did the car have a fuel filter?)
MAF
Vacuum leaks.
Last edited by Glyn M Ruck; 02-20-2012 at 10:24 PM.
#13
MBworld Guru
My understanding is that the CPR isn't even used to determine TDC - it is used for nothing more than to tell the ECU that the engine is actually rotating. If no CPS signal is sent to the ECU, then it assumes the engine is frozen and not rotating and therefore does a fuel cut-off, for safety reasons. Symptoms of a failed CPS are that the engine just shuts off -like turning the key to position 0 - with no error codes, hesitation, stuttering, etc.
#14
Super Moderator
No - on the M112 it is used to determine TDC. You are however correct for start enable it has to confirm that the engine is not rotating so that you can't engage the starter motor into a spinning ring gear. The ECU in the diagram above also interrogates the temp sensor to establish engine temperature & whether mixture enrichment is required or not for start.
Partial CPS failure usually requires a cool down period before a restart will be enabled.
Total CPS failure will result in no start.
The vehicle should throw one of the following codes. P0335 being the most common.
P0335 = Crankshaft Position Sensor A Circuit Malfunction
P0336 = Crankshaft Position Sensor A Circuit Range/Performance
P0337 = Crankshaft Position Sensor A Circuit Low Input
P0338 = Crankshaft Position Sensor A Circuit High Input
P0339 = Crankshaft Position Sensor A Circuit Intermittent
Partial CPS failure usually requires a cool down period before a restart will be enabled.
Total CPS failure will result in no start.
The vehicle should throw one of the following codes. P0335 being the most common.
P0335 = Crankshaft Position Sensor A Circuit Malfunction
P0336 = Crankshaft Position Sensor A Circuit Range/Performance
P0337 = Crankshaft Position Sensor A Circuit Low Input
P0338 = Crankshaft Position Sensor A Circuit High Input
P0339 = Crankshaft Position Sensor A Circuit Intermittent
Last edited by Glyn M Ruck; 02-21-2012 at 10:55 AM.
#15
MBWorld Fanatic!
Thread Starter
so as an update from last time.
Last night I ran the on board diagnostic....read 11.9-12v. the car would crank but not start....great....so this morning, got a trickle charger from a friend, gave it a 30 min charge. took off the trickle charger. it read 12.5v
started the car, it starts! everything is good. except see the rpm drop a bit, then the car starts to shake and my car automatically revs itself up (keep in mind im in 'park'). then i rev it a bit and i feel it bog down again....it was about to stall out but the car kept it going my allowing it to rev again. i think i will allow the car to warm up in park to see if it will die out under some load so i can get it to throw the code because as of right now, there is no malfunction being thrown....
will keep you guys posted and thanks glyn as well as the rest of the members here patiently replying to this thread... id be at the stealership without you guys!
UPDATE: so i let the car run for 18 min from cold start. the temp is warmed up to normal driving temp and it dies...dies when you put it under load, dies when you it in gear. battery voltage when the car starts 12.3v...drops to 11.x...raises to 13.7v and then dies. the annoying thing is that i am not getting any malfunction messages on the dash. and my obd ii reader isnt picking anything up.
Last night I ran the on board diagnostic....read 11.9-12v. the car would crank but not start....great....so this morning, got a trickle charger from a friend, gave it a 30 min charge. took off the trickle charger. it read 12.5v
started the car, it starts! everything is good. except see the rpm drop a bit, then the car starts to shake and my car automatically revs itself up (keep in mind im in 'park'). then i rev it a bit and i feel it bog down again....it was about to stall out but the car kept it going my allowing it to rev again. i think i will allow the car to warm up in park to see if it will die out under some load so i can get it to throw the code because as of right now, there is no malfunction being thrown....
will keep you guys posted and thanks glyn as well as the rest of the members here patiently replying to this thread... id be at the stealership without you guys!
UPDATE: so i let the car run for 18 min from cold start. the temp is warmed up to normal driving temp and it dies...dies when you put it under load, dies when you it in gear. battery voltage when the car starts 12.3v...drops to 11.x...raises to 13.7v and then dies. the annoying thing is that i am not getting any malfunction messages on the dash. and my obd ii reader isnt picking anything up.
Last edited by bheng; 02-21-2012 at 05:00 PM.
#18
MBWorld Fanatic!
Thread Starter
i mean when i used a trickle charger...the power went back up and is holding charge. but im down to do a load test...i suspect to use a multimeter?
Last edited by bheng; 02-21-2012 at 10:15 PM.
#19
MBworld Guru
No - on the M112 it is used to determine TDC. You are however correct for start enable it has to confirm that the engine is not rotating so that you can't engage the starter motor into a spinning ring gear. The ECU in the diagram above also interrogates the temp sensor to establish engine temperature & whether mixture enrichment is required or not for start.
Partial CPS failure usually requires a cool down period before a restart will be enabled.
Total CPS failure will result in no start.
The vehicle should throw one of the following codes. P0335 being the most common.
P0335 = Crankshaft Position Sensor A Circuit Malfunction
P0336 = Crankshaft Position Sensor A Circuit Range/Performance
P0337 = Crankshaft Position Sensor A Circuit Low Input
P0338 = Crankshaft Position Sensor A Circuit High Input
P0339 = Crankshaft Position Sensor A Circuit Intermittent
Partial CPS failure usually requires a cool down period before a restart will be enabled.
Total CPS failure will result in no start.
The vehicle should throw one of the following codes. P0335 being the most common.
P0335 = Crankshaft Position Sensor A Circuit Malfunction
P0336 = Crankshaft Position Sensor A Circuit Range/Performance
P0337 = Crankshaft Position Sensor A Circuit Low Input
P0338 = Crankshaft Position Sensor A Circuit High Input
P0339 = Crankshaft Position Sensor A Circuit Intermittent
#20
Super Moderator
Oh! Rodney - I have seen occasions it throws no codes as well. Most recently on a friends S Class. Nada, nothing. zilch! Changed the CPS & she fired right up.
More irritating is the dual failure of fuel system & CPS together & no codes. Shot CPS & shot fuel pump or solenoid & NO codes. OBD are not perfect. Had this recently on a friends W202 C240 & it had a blown fusible link!
More irritating is the dual failure of fuel system & CPS together & no codes. Shot CPS & shot fuel pump or solenoid & NO codes. OBD are not perfect. Had this recently on a friends W202 C240 & it had a blown fusible link!
#21
MBWorld Fanatic!
Thread Starter
Oh! Rodney - I have seen occasions it throws no codes as well. Most recently on a friends S Class. Nada, nothing. zilch! Changed the CPS & she fired right up.
More irritating is the dual failure of fuel system & CPS together & no codes. Shot CPS & shot fuel pump or solenoid & NO codes. OBD are not perfect. Had this recently on a friends W202 C240 & it had a blown fusible link!
More irritating is the dual failure of fuel system & CPS together & no codes. Shot CPS & shot fuel pump or solenoid & NO codes. OBD are not perfect. Had this recently on a friends W202 C240 & it had a blown fusible link!
#22
#23
MBWorld Fanatic!
Thread Starter
autohausaz
its bosche so oe
and it was cheaper than buying it from kragen....even with shipping for a 2 day ....-___-
its bosche so oe
and it was cheaper than buying it from kragen....even with shipping for a 2 day ....-___-
Last edited by bheng; 02-22-2012 at 12:51 PM.
#24
Super Moderator
You take it to a battery shop that can place it under load & see how quickly it dumps it's charge. Many batteries will hold a surface charge but the minute you load them the voltage goes south.