Camshaft position wave form
vehicle has rough idle that will come and go, sometimes stall out. Runs fine off idle. Intermittent circuit codes for camshaft position sensor. Ford changed sensor style in 2013 3 wire. Sensor is now powered by 12v instead of 5v. Scope wave form for both camshafts and crankshaft are all good, except the camshafts will pull voltage from 5v down and return to 5v, with 12v feeding sensor should it return 5v or 12v. I have alldata for service info and the compon description does not give any indication of what PCM is looking for as far as voltage.
If it is a simple on off switch it will produce a 12 volt square wave. If it has a built in resistance it could deliver a 5 volt or other voltage square wave. This would be similar to Chrysler feeding 8 volts and delivering a 5 volt signal.
Understand that principal. But I can not find any definitive data to prove if it is indeed a 5v return. I am tempted to purchase a new sensor and trigger it on the bench to prove function. Thank you for your input!!
2014 F-250 6.2 cmp ckp and the cmps are toggling at 5v. HTH
I think that the 5V on the signal line is supplied by the ECM. The 12v of the sensor only feeds the switch circuitry inside the sensor to pull the ECM supplied 5V down and release it. Unplug the sensor and see what the voltages are.
In AllData under the pinpoint test DR: Camshaft Position (CMP) Sensor: Introduction (not the pinpoint test: DR: Camshaft Position (CMP) Sensor: Pinpoint Test) is a list of each vehicle and what type of CMP sensor they use. It has been my experience that they pull the 12 volt reference to ground. I haven't seen the exact vehicle you are working on yet but all the vehicles I've seen with a…