Crankshaft Position Sensor Diagnosis
#50
#51
Thanks again, I was thrown for a bit because of the shielding on a A/C output sensor, on the diesel side we never had any shielding on that type sensor, only on data communication wiring and throttle position wiring, back in early 2000's the A/C output sensors were popular but failures were common, all speed/position sensors in use with today's engine are hall effect sensors with far fewer failures.
#53
Oh my, it's been a long time. I looked over the thread and didn't see where the DC voltages of the CPS signal wires were ever measured (may have missed it though). Anyway, when the engine is not running, the two signal wires should be at some equal DC voltage since the CPS is a magnetic pickup and will only force a voltage when it's picking up movement, i.e. a changing magnetic field. It's probably likely that the DME biases the wires to some value convenient for detecting an AC signal, and I'd guess 2.5 V which is half the 5 V the DME runs on. So, both being 2.5 V sounds, at first glance, like the right condition.
BTW since fixing this issue and a similar throttle positioner issue (poor electrical contacts), the engine has accumulated about 45k miles and it has been running perfectly.
BTW since fixing this issue and a similar throttle positioner issue (poor electrical contacts), the engine has accumulated about 45k miles and it has been running perfectly.
#54
Oh my, it's been a long time. I looked over the thread and didn't see where the DC voltages of the CPS signal wires were ever measured (may have missed it though). Anyway, when the engine is not running, the two signal wires should be at some equal DC voltage since the CPS is a magnetic pickup and will only force a voltage when it's picking up movement, i.e. a changing magnetic field. It's probably likely that the DME biases the wires to some value convenient for detecting an AC signal, and I'd guess 2.5 V which is half the 5 V the DME runs on. So, both being 2.5 V sounds, at first glance, like the right condition.
BTW since fixing this issue and a similar throttle positioner issue (poor electrical contacts), the engine has accumulated about 45k miles and it has been running perfectly.
BTW since fixing this issue and a similar throttle positioner issue (poor electrical contacts), the engine has accumulated about 45k miles and it has been running perfectly.
#55
MK, according to wiring diagram, there is a ground shield, does it suppose to touch vehicle frame? I accessed the DME, connector III and found 980ohm to the crank sensor on pin 46 and 32, which indicate that the connectivity is good for the sensor coil. But the ground wire pin 45 is open and doesn't go to the vehicle ground. And when I measured the connector side under the car next to the sensor, the ground does connect to vehicle ground. Thus I think it means there is disconnect somewhere? I guess my other question is, does the DME pin 45 goes to vehicle ground or it should be insulated?
#57
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dporto (03-25-2023)