When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
'12 E63 Wagon, '31 Model A Ford, '19 Miata, '19 GTI
Crankshaft Position Sensor - DIY Help / WIS?
Hey Folks,
My 2012 E63 AMG wagon has thrown a Check Engine Light that is a P001685 - "The position of the intake camshaft (cylinder bank 1) is implausible relative to the position of the crankshaft. There is a signal above the permissible limit."
After doing some initial searching around, it looks like a few others have suggested that replacing the Crankshaft Position Sensor might resolve this problem. As always, I'd like to pull together a video DIY as I do this, but it brings up a few questions:
For anyone that's done this, is it easier to get at it from the top or the bottom? I've got flexible extensions and small e8 torx ready but not sure the best way to approach. If coming from the top, how much do I need to remove to get at it?
I have a buddy with WIS access, but he said that he couldn't find a document for the M157 crankshaft position sensor procedure. Anyone know if they call it something different, or know of a document number I should have him look up?
Inquire your friend or search for WIS article AR15.10-P-2000ELB "Remove/install camshaft Hall sensor." I may have posted it here. Hint: you can swap them with basic tools in 20 mins (5 min/ea) at $38.44/ea, p/n A2769051000.
Recommend before you order replacements, swap the camshaft sensors from one cylinder bank to the other and see if the error follows the faulty sensor. All sensors are the same part. Good luck.
'12 E63 Wagon, '31 Model A Ford, '19 Miata, '19 GTI
They found that one, but that's for the Camshaft Position Sensor, right? Am I wrong that there's only one Crankshaft position sensor and either could potentially cause this fault? Or is the M157 different? (it totally could be - I'm used to Miatas )
I should have included this above, but I actually already had the camshaft position sensors swapped (they seemed to be leaking, so I had my local shop do them when it was in for service) to no avail. Replacing the crankshaft sensor seems to be a next-up troubleshooting step.
Cheers,
Mike
Last edited by Michael Adrian; Oct 30, 2020 at 10:00 PM.
Reason: spelling
The M157 can adjust camshafts steplessly up to 40 degrees crank angle. The ECU reads from the following sensors:
.
Intake camshaft Hall sensors, positions (B6/4-5)
Exhaust camshaft Hall sensors, positions (B6/6-7)
Coolant temp sensor (B11/4)
Pressure sensor downstream of throttle valve actuator, engine load (B28/7)
Crankshaft Hall sensor, engine RPM (B70)
Oil sensor (B40)
These readings (some are double-checked by compute) allow ECU to send signals to the camshafts electromagnet solenoids (Y49/5-8) to adjust the camshafts. If you already swapped out the camshaft sensors, your next steps may include the crankshaft sensor (p/n A2769051200 around $40, need 1) and electromagnet solenoids (p/n A2761560790 around $40, need 4). If you get to the solenoids, my previous recommendation to relocate before replacing stands. Hope this helps.
'12 E63 Wagon, '31 Model A Ford, '19 Miata, '19 GTI
Thanks, that's super helpful - sounds like I'm headed down the right path. I've got the new crankshaft sensor, so that's an easy next up. My friend's still only finding a couple of references to B70 (a wiring diagram and a component location). It looks like it's just above the bellhousing on the driver's side of the car. Can that be gotten to from the top (I know this engine bay is super tight), or easiest just to get at it from the bottom?
Also, know of any good DIY or WIS on the electromagnet sensors?
You may want to review WIS article AR05.20-P-6010EL "Check basic position of camshafts." Regarding B70, it is located in the back of the engine block, near top of the tranny bell housing, on the driver's side roughly 11 o'clock.
'12 E63 Wagon, '31 Model A Ford, '19 Miata, '19 GTI
Thanks! Any idea if that's easier to reach from the top or the bottom? Just getting to those back spark plugs is a real pain from the top - can't imagine B70 is any easier...
There a 4 camshaft sensors. Bank 1 is the left side of the motor when viewed from in front of the car(passanger's side on RHD car). Intake cam is on the top/inside of the head, Exhaust cam is on the bottom/outside of head. These are a know issue and the original part numbers leak and allow oil into the harness. I would suggest replacing all 4 with the newest number and thoroughly cleaning up and drying with compressed air the harness connectors for the cam sensors. More than likely this(or just a bad sensor that is not leaking...) is the issue, not the crank sensor. If you loose the crank signal, the car will not run and or die with no signs or warnings. Please pull you can sensor connectors asap and see if there is oil in them as it can wick into the harness and cause issues with O2 sensors and Engine ECU(killing them, very expensive). My 2012 E550 had this same issue earlier this year. Same exact code and sensor failure. Mine had wicked into the harness and a few weeks later, I had an O2 sensor that failed from oil in the harness. I caught it quickly and was able to clean it up and it has not come back since(I've checked it once a month since replacing/cleaning). Good luck and let us know what you find.
Bank 1 Intake Cam Sensor
Bank 1 Exhaust Cam Sensor
Last edited by nota_amg; Oct 29, 2020 at 02:31 PM.
'12 E63 Wagon, '31 Model A Ford, '19 Miata, '19 GTI
Well, I already replaced all four Camshaft sensors, and there was apparently oil on them. They cleaned them out with some electrical cleaner and let them air dry before plugging them back in...with no luck. From your experience, could this have caused additional problems (e.g. the ECU trouble)?
Last edited by Michael Adrian; Oct 30, 2020 at 10:00 PM.
nota_amg brings a good point to check the engine harness. Unplug from ECU and see if oil traveled inside the sheath or braided strands and contaminated the ECU connector.
Well, I already replaced all four Camshaft sensors, and there was oil on them. I cleaned them out with some electrical cleaner and let them air dry before plugging them back in...with no luck. From your experience, could this have caused additional problems (e.g. the ECU trouble)?
Originally Posted by maxusa
nota_amg brings a good point to check the engine harness. Unplug from ECU and see if oil traveled inside the sheath or braided strands and contaminated the ECU connector.
Yes, as max says, check that ecu plug. Oil in the ECU can cause havoc.
I wonder if you could get Mercedes to cover this, as it is a "known issue".
Question for people who have done this, how do you know which one is newer when ordering if you are just looking up part numbers? I gotta do mine here soon as well.
MY12 vehicles are out of factory warranty by now. If you have extended or 3rd party, you may try.
I think you refer to nota_amg comment about "replacing with the newest number." I am certain that he means the most current part number for the part in question. Over time, part numbers do change for seemingly the same component because of improvements, different OEM contract, rebuilding, reclassification, etc. And so it happens that the camshaft hall sensor A2769051000 I listed in the beginning is the newest part as of this writing that replaced A2761530028, A2769050143, A2769050800, A2769051100. Always do your own part validation before ordering.
How one knows this information? Ideally from the authoritative source, the manufacturer. Mercedes maintains EPC (Electronic Parts Catalog), which has this information. Dealers and serious part resellers subscribe to it. They usually do not have a problem validating a part for you. Some of us have access.
Here EPC shows the history of part number succession for the crankshaft sensor.
'12 E63 Wagon, '31 Model A Ford, '19 Miata, '19 GTI
First of all, I just want to thank you all for the massive amount of help so far. Tonight, I went and checked the Camshaft Position Sensors & Plugs to see if there was oil left, and it looks like they're in pretty good shape. I then pulled the ECU out, and below are the pictures of the plugs. Some of it is just shiny plastic, but I believe there's a very little bit of residue there on the plugs...
Is there a good way to clean this up if I wanted to for good measure? Electrical cleaner and air dry like before? Would that damage anything?
Lastly, I went to try to get at the crankshaft sensor(b70) (since I already have the new one I figured I might as well swap it). I tried both to even see it from the top by removing air filters and foam pads to no avail. I also tried removing the belly pan to see if I could see it from the bottom, and I don't think my hands are small enough to even get up to touch it. Any tips or tricks for getting to it?
The location of the crankshaft sensor is very difficult to reach from top. The vacuum pump and heat line on bulkhead leaves zero space. I am doing maintenance this weekend and can examine approach from top and bottom to the sensor. By the way, your ECU connector looks dry.
'12 E63 Wagon, '31 Model A Ford, '19 Miata, '19 GTI
The camshaft solenoid plugs (the ones on the very front of the motor near the camshaft position sensors) look a bit goopy...could that cause the problem?
This connector looks okay. Recommend cleaning solenoid connectors and swapping solenoids to see if the error follows. The solenoids are the same part number for intake and exhaust camshafts. Just to speculate, theoretically, if the solenoid went bad, it may fail to adjust the respective camshaft properly. The camshaft sensor then reports an implausible position.
This connector looks okay. Recommend cleaning solenoid connectors and swapping solenoids to see if the error follows. The solenoids are the same part number for intake and exhaust camshafts. Just to speculate, theoretically, if the solenoid went bad, it may fail to adjust the respective camshaft properly. The camshaft sensor then reports an implausible position.
'12 E63 Wagon, '31 Model A Ford, '19 Miata, '19 GTI
I may give that a try, but it looks like I Have to pull the whole oil filter housing off to get to the solenoids on bank 2.
I cleaned out the plugs and dried them all off with no progress. I also removed the driver's side cat / exhaust to see if I could get at the crankshaft sensor, and unfortunately my huge hands made no progress.
I looked into the issue of replacing the crankshaft hall sensor. Here are my conclusions:
.
From top. The sensor is located straight underneath the vacuum pump on the block flange half an inch away from the bell housing edge. The space is very tight, but enough to feed a long wobble extension from top to remove the torx retaining screw. It looks like a T25. Once you stick your hand, down there, there is no seeing what you are doing, and so one needs to 'imagine' the space well. The wire is in unique temp protective sleeve, which helps. Follow the ribbed sleeve to the sensor/connector. To get to it from top, one needs to do the following:
Unscrew cap on coolant expansion reservoir.
Remove lower engine paneling.
Attach drain hose to left fitting on radiator.
Unfasten drain (red) screw on radiator and drain coolant. I got by with partial drain of 4L.
Remove engine cover.
Remove left-hand air filter box.
Remove insulation on left rail.
Disconnect engine wiring harness from ECU and rear intake manifold.
Unclip engine wiring from intake manifold and move aside.
Optionally, remove the plastic sleeve over the left-hand engine eye bracket. Remove bracket (3 torx screws).
Disconnect thick vacuum line from pump, intake manifold, move aside.
Detach thin vacuum hose from pump.
Detach coolant line to heat exchanger on bulkhead and move aside. This line is exactly behind the vacuum pump.
Now you can access the bolts. Remove 3 bolts holding the vacuum pump.
Remove vacuum pump. Note/mark the position of the actuator (to reinsert).
Use long extension to detach torx screw holding the crankshaft sensor. It will help if another person guides the torx bit from bottom.
Pull the sensor up by the ribbed wire.
Install in the reverse order.
Push coolant back into the radiator from the attached hose, or pour in to the expansion reservoir allowing air/bubbles out.
From bottom. The sensor can be reached from bottom left-hand side. However, the space is very tight for the tools. Perhaps, there is a miniature motorized wrench or shorty Torx screw driver one can get there. I do not believe it is feasible to replace the sensor from bottom. But the bottom reach helps to unclip the connector, position the screw, guide the torx extension from top.
Remove lower engine paneling.
Drain engine oil.
Remove engine dip stick. One T25 screw on the left-hand engine eye bracket top side. The other is on the engine oil pan.
Optionally, remove the left-hand downpipe.
This shall open enough space to reach the crankshaft sensor from bottom. Like in the topside steps, work blinded. Follow the ribbed wire sleeve to the sensor.
Install in the reverse order.
I will post photos I made with a bore snake camera shortly. Sorry for the grainy res. Best of luck.
One more thing. I took a rotary tool to grind many razor-sharp edges around the space; the aluminum heat shielding, even the cylinder head. Reduced cuts and scratches significantly.
With vacuum pump removed, there is enough space to reach the crankshaft sensor from top. Note the large camshaft opening in top left corner. This is where vacuum pump mounts. You can barely see the sensor (follow the ribbed wire).
The crankshaft sensor is the one with ribbed wire sleeve. There is another (temp) sensor above it to be ignored.
I can reach the crankshaft sensor from top after removing the vacuum pump, but no space to maneuver., only to pull the sensor out/guide it in.
Here is the crankshaft sensor and torx screw. Note the ribbed sleeve over the wire. Will help navigate to it.
This reads like a correlation code issue...
That's the ECU flagging one of the camshaft being mislocated. . . that's either a worn VVT Gear or a shifted reluctor wheel. None of these 2 options are cheap!
This happen after excessive ratling was ignored long enough - - Now tab seriously goes up with injectors, HPFP and valve cover coming off... likely Bank1 overworked by dry lubing HPFP.
At that time camshafts are inspected for lobe wear and HPFP+PCV a pretty good idea.
All of this would have been prevented with normal effective oiling.... marginal pressure overworks VVT pins.
Given the busy production of steel particles, I'd keep cleaning that bypass valve. 🤞
++++ Bank1 is identified... (ie. dry HPFP's shot!)
+++ Timing chain may be assessed for stretching caused by HPFP abuse..
~$3G
Last edited by CaliBenzDriver; Oct 15, 2024 at 01:57 AM.
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
)
