Porsche 944 - Crankshaft Position Sensor Testing & Replacement Tutorial 

That’s high praise sir, thank you! I think it serves a niche community at this point, but it also seems to provide tremendous value to those who are part of the group.

Yep, or a small piece of painters tape. 👍🏼

Nice, congrats on the purchase! Certainly a lot to learn my friend! Glad the content is helping you get started. Cheers!

Thank you! I certainly wasn’t trying to discourage others from producing content, but I appreciate the compliment. There isn’t a lot of info out there on the S2 cars, so I’m sure you could still add some useful tips to the existing body of work. Cheers!

Yeah, you can spend 45 minutes to an hour removing just one sensor if it’s really jammed up. Pretty ridiculous. 😂

Oh man, that sounds terrible! I won’t ask who the parts outfit was, but I have a couple ideas from my own experience based upon similar part mis-picks. 😂

Thank you! Everything on the car worries me… 🤣

They sit in a terrible location for sure. 😂

I’m trying to cut down on the fluff. 😂

@@JGStone The “over 1 million ohms” is synonymous with an infinite reading on the meter, and it sounds like that’s what your getting, if the other reading the within spec, they’re probably ok.

@NC944er Aight thank you m8, guess I will just take em out and continue visual inspection, kinda hoping they are busted so I have finally solved this cars mystery.😅

@NC944er After visual inspection while taking both out, they both look fairly new... and rpm gauge does work, so I think I'll switch the two sensors and see if something changes.

The speed sensor counts the teeth on the flywheel and sends this signal as pulses to the DME computer to determine engine speed in RPM. The DME then sends this data to the tachometer gauge on the dash. If the speed sensor tests good and the engine is running fine, you’d want to inspect the tachometer gauge and related connections and electrical components.

Nope, as long as the bracket was correctly gapped beforehand, the sensors can simply be swapped out with the bracket in its existing position.

@@NC944er awesome thank you!

Hey! So while the speed sensor determines the RPM, which is sent to the DME, and then the DME sends a signal to the tachometer gauge, if the speed sensor has failed, the engine would run VERY poorly if at all, because the DME wouldn’t have a reliable signal to correctly apply fuel injector cycling. So in your case, I would look at the tachometer itself… sometimes the connections behind the gauge cluster can become corroded or the pins get pushed out of the plugs, so they have a poor connection with the gauges. The circuit boards for the tachometer also have components that can burn up or a failed circuit trace. You’d have to pull the steering wheel off and then remove the gauge cluster to get in there and inspect for those issues. If the tachometer checks out ok, there could be an issue with the wiring that leads from the DME to the gauge cluster.

@@NC944er awesome thanks chief, you're an absolute legend!

That sounds super annoying! There are quite a few little crevasses on that side of the engine where things can disappear. It may be worthwhile to poke around with a magnet to see if you can grab it. Also, you can look through the clutch inspection hole at the bottom of the bell housing and/or pull the starter off to get a view at the lowest point inside, see if maybe the bolt is hanging around down there.

⁠@@NC944erpulled the starter off and got it thank you. I’m not getting any signal from the pins for the reference sensor at the DME. I’ve just replaced both sensors so I’m stumped. Hopefully not the loom itself

Have you tested the speed/reference sensors? Are you seeing tach bounce when cranking the engine? Is there a factory alarm installed on the car? If so, have you bypassed the control module to rule that out? The DME Computer is another possible suspect. Here is another resource to help start diagnosing “no start” issues: www.clarks-garage.com/shop-manual/ts-01.htm

Thank you we will try those! We will keep you updated!

No, the wiring connector bracket doesn’t need to be bolted up for the engine to run, just that the sensors are properly connected. If the new sensors don’t resolve the issue, I’d check for spark and fuel. Here is a helpful resource to get started - www.clarks-garage.com/shop-manual/ts-01.htm

Awesome thank you, much appreciated, very helpful. Does the sensor need to be regapped if the bracket wasn't loosened? Can I only unbolt the sensor and drop in a new one?

@@RichiWang-ef4mp Yeah, in most cases you can leave the mounting bracket adjustment as it is and simply swap out the sensors, unless you have reason to believe that it’s not adjusted correctly or was taken off for other recent work like a clutch replacement, etc. If the car was previously running fine with the current bracket setting, you should be good to leave it alone.

It’s greater than 1M ohms, so essentially infinite on some ohmmeters. If you get a lower reading, you’ll know something is off.

@@THEPASSIONATEDRIVER Yeah, the general process here will be for the 8-valve engines, some of it will align for the S2, but not all. The S2 only has one reference sensor due to differences in the flywheel.

Ah I see. Thanks. Do you know which pins do I use to check resistance for the reference sensor on my 3 row pin connector?

@@THEPASSIONATEDRIVER Here are some shots of the S2/968 pinout diagram, check out 47 and 48... forums.pelicanparts.com/porsche-924-944-968-technical-forum/675801-944s2-dme-pin-out-diagram.html

Thank you