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Before i attempt to remove the starter and replace it, I need help to figure out if it is even the problem or not. Here are my problems, troubleshooting, and replacements i did over the past few weeks.
Description of Problem:
My wife's w204 c250 throw P010664 code (intake manifold pressure sensor has a malfunction; implausible signal) whenever the car intermittently does not crank (about every 3-5 successful starts). This is what happens when it happens to not crank. I hear a click and then a continuous low humming noise. Seems that starter trying to start but it gets stuck? Something with solenoid possibly? You have to put your head down close to the engine bay. It sounds like its coming from the aft bottom of the engine bay. In any case, I am able to start the car by removing the starter relay and jumpering pins 1 & 2 of the starter relay which are the contacts that are closed by the relay when the relay is activated. I always carry the special jumper wire i made with me when driving the car now.
Troubleshooting/Replacements:
- Starter relay and fuse check out ok. I did swap out the starter relay for a brand new one and even check the existing starter relay by applying 12V to it and checking the contact closures with a multimeter.
- Checked ECM if it closes the circuit to ground (for starter relay activation) and that checks out.
- Checked battery which is 12.6V. Even try jumpstarting to see if battery was the issue but still intermittent no crank.
- Replaced both MAP sensors but still intermittent no crank.
Before i attempt to remove the starter and replace it, I need help to figure out if it is even the problem or not. Here are my problems, troubleshooting, and replacements i did over the past few weeks.
Description of Problem:
My wife's w204 c250 throw P010664 code (intake manifold pressure sensor has a malfunction; implausible signal) whenever the car intermittently does not crank (about every 3-5 successful starts). This is what happens when it happens to not crank. I hear a click and then a continuous low humming noise. Seems that starter trying to start but it gets stuck? Something with solenoid possibly? You have to put your head down close to the engine bay. It sounds like its coming from the aft bottom of the engine bay. In any case, I am able to start the car by removing the starter relay and jumpering pins 1 & 2 of the starter relay which are the contacts that are closed by the relay when the relay is activated. I always carry the special jumper wire i made with me when driving the car now.
Troubleshooting/Replacements:
- Starter relay and fuse check out ok. I did swap out the starter relay for a brand new one and even check the existing starter relay by applying 12V to it and checking the contact closures with a multimeter.
- Checked ECM if it closes the circuit to ground (for starter relay activation) and that checks out.
- Checked battery which is 12.6V. Even try jumpstarting to see if battery was the issue but still intermittent no crank.
- Replaced both MAP sensors but still intermittent no crank.
If I understood your advanced testing correctly: the problem is not relay and not starter but likely drive authorization.
The car logic is failing the key authentication. You will use your MB scanner to troubleshoot that.
There a chance this is going to land you to question the ignition slot module (EIS) that needs a 5mn soldering job.
Last edited by CaliBenzDriver; Nov 28, 2024 at 02:00 AM.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
I would not rule out the starter at this point. When they begin to fail, it can be intermittent or just suddenly no start. Have you tried the method of tapping (smacking) the starter with a hammer while some else tries to start the engine?
@Stevie818 - I am leaning towards a dying starter OR loose ground or connection somewhere. It might be worth your time to bench test the starter.also, Something like @JettaRed suggested. The ol hammer trick, is a sure tell sign your starter is going out.
Remove the starter from the car and give it 12v to see if it throws the gear out as if it were to start the car. If it gives your trouble or hesitates when given a pure 12v your starter is likely bad.
I’ve had to do this countless times on my 2nd gen Cummins, they are known for electrical gremlins.
is your wife’s car leaking Any oil?? The oil filter housing is known to leak on these cars (I’ve had to replace my OFH and gasket) as it sits right above the starter and willl leak on to it and kill the starter.
Something to think about and investigate while you’re under the car.
If I understood your advanced testing correctly: the problem is not relay and not starter but likely drive authorization.
The car logic is failing the key authentication. You will use your MB scanner to troubleshoot that.
There a chance this is going to land you to question the ignition slot module (EIS) that needs a 5mn soldering job.
Yeah I've seen some videos on that. I'm hoping I won't have to go there (yet). I saw how the entertainment center console needs to be taken apart to get to it. I may have to deal with this if starter does not turn out to be the issue.
@Stevie818 - I am leaning towards a dying starter OR loose ground or connection somewhere. It might be worth your time to bench test the starter.also, Something like @JettaRed suggested. The ol hammer trick, is a sure tell sign your starter is going out.
Remove the starter from the car and give it 12v to see if it throws the gear out as if it were to start the car. If it gives your trouble or hesitates when given a pure 12v your starter is likely bad.
I’ve had to do this countless times on my 2nd gen Cummins, they are known for electrical gremlins.
is your wife’s car leaking Any oil?? The oil filter housing is known to leak on these cars (I’ve had to replace my OFH and gasket) as it sits right above the starter and willl leak on to it and kill the starter.
Something to think about and investigate while you’re under the car.
keep us updated
ant
Thanks @JettaRed and @antboii for the suggestions. I'm going to try to pull out the starter today and do my own bench test on it. I'm guessing it might be the solenoid sticking but i havent dealt with starters too much. Replaced one on the RSX before but the symptom was pretty obvious and persistent so the solution was to simply replace the starter. Although, the actual task of doing the replacement on a small japanese car was no walk in the park. In any case, i will also check the oil filter housing for any leaks.. A few days ago I noticed some oil leakage near the bottom of the block (just below the crankshaft pulley). I attached a pic here. A year ago as i was replacing the blow-off valve, I noticed that there was a little bit of oil in the turbo intake tube but didn't think it was a big deal at the time. Hope its not the turbo leaking oil. Definitely going to check the oil filter housing as that seems to be quite plausible wrt the starter/starting problem. However, given that this oil leak is at the front of the engine rather than the rear where the oil filter housing is, i am dreading that I may be dealing with two separate problems that may not be related: intermittent no crank and the aforementioned oil leak. Red arrows indicate presence of engine(?) oil
Thanks @JettaRed and @antboii for the suggestions. I'm going to try to pull out the starter today and do my own bench test on it. I'm guessing it might be the solenoid sticking but i havent dealt with starters too much. Replaced one on the RSX before but the symptom was pretty obvious and persistent so the solution was to simply replace the starter. Although, the actual task of doing the replacement on a small japanese car was no walk in the park. In any case, i will also check the oil filter housing for any leaks.. A few days ago I noticed some oil leakage near the bottom of the block (just below the crankshaft pulley). I attached a pic here. A year ago as i was replacing the blow-off valve, I noticed that there was a little bit of oil in the turbo intake tube but didn't think it was a big deal at the time. Hope its not the turbo leaking oil. Definitely going to check the oil filter housing as that seems to be quite plausible wrt the starter/starting problem. However, given that this oil leak is at the front of the engine rather than the rear where the oil filter housing is, i am dreading that I may be dealing with two separate problems that may not be related: intermittent no crank and the aforementioned oil leak. Red arrows indicate presence of engine(?) oil
A few possible sources for the leaks on the front of the engine. First, the oil supply line from the cylinder head to the turbo. An O-ring on the end of the line where is bolts to the cylinder head deteriorates with time and heat. This causes pressurized oil to leak from the line. A simple and inexpensive fix. Second, the banjo bolt on the other end of this line, where it attaches to the turbo. A bulletin was released for this issue, as well as an updated part. Again, a simple and inexpensive fix that can be combined with the first item. Third, the cylinder head cover gasket (often referred to as the valve cover gasket). This tends to leak more often at the rear of the engine but again deteriorates with time and heat. It's a little bit more work, but it's fairly straightforward to replace. Replace the four gaskets around the spark plug tubes at the same time as the cylinder head cover gasket.
Yes, your oil leaks at the front of the engine are a separate issue.
A few possible sources for the leaks on the front of the engine. First, the oil supply line from the cylinder head to the turbo. An O-ring on the end of the line where is bolts to the cylinder head deteriorates with time and heat. This causes pressurized oil to leak from the line. A simple and inexpensive fix. Second, the banjo bolt on the other end of this line, where it attaches to the turbo. A bulletin was released for this issue, as well as an updated part. Again, a simple and inexpensive fix that can be combined with the first item. Third, the cylinder head cover gasket (often referred to as the valve cover gasket). This tends to leak more often at the rear of the engine but again deteriorates with time and heat. It's a little bit more work, but it's fairly straightforward to replace. Replace the four gaskets around the spark plug tubes at the same time as the cylinder head cover gasket.
Yes, your oil leaks at the front of the engine are a separate issue.
Thanks on the tip for the oil leak locations. I will take a look when I figure this NO Crank issue out. I do notice that when the car does start, that there is rough idle or weak acceleration. I wonder if this is related to the NO crank issues. Maybe crankshaft position sensor? Gosh failures are usually supposed to happen at different times...not all at once!
I think I read the starter cranked well using bypass trick near the fuse-box... right?
From that I understood nothing was commanding the control relay...
Meaning the starter can't work while it's not commanded.
Hey CaliBenz, the plot may be thickening. Yes, the starter cranks right up whenever i bypass the starter relay in the fuse box. After i got the front of the car on jacks, i did not notice any oil leaks near the starter (only the front which is a different problem). I was able to loosen the two long bolts that hold the starter in place. However, before i decided to attempt to remove the starter altogether i decided to start the car up again. NO crank with the accompanying humming noise. Retrieved my mechanic's stethoscope and put it up against the starter solenoid. No loud humming as I would expect. Put the stethoscope on the torque converter housing and humming noise is much louder...ill try to put the stethoscope elsewhere. I googled 'transmission humming' but that is when transmission/car is in motion and gears are bad.
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