And the sensors are fairly bulletproof.
Wiring issues are at least as common (if not more so) than actual sensor failures.
Examine your wiring harness and connectors in detail. You can also check your sensor; I think you will find it ok.
The cam sensor sees a wheel behind the cam sprocket. It is not a toothed wheel in the normal manner. It has pieces of metal of varying width in places, with other pieces of varying widths removed. This lets the sensor report to the ECU not just how fast the cam is turning, but also which cylinder is presently at TDC.
As I said, my 05 pd will run with the sensor unplugged. The PD educational pdf in the photo section indicates that is normal. (By the way the BEW will not run without the crank sensor, but the BRM can run as long as either the crank or the cam sensor is working.)
The cam sensors normal resistance is greater than 6 Mohms for any and all pins to ground, with either positive or negative ground.
The sensor pin to pin readings were all greater than 6 Mohms, with the following exceptions:
Pin 1 neg to pin 3 positive = 2.89 Mohm.
Pin 2 neg to pin 3 positive = 1.95 Mohm.
The plug (wiring harness) pin to ground(negative) readings (key off) are :
pin1 = 26 to 50 ohms (varying, seemed mostly 50 ohms)
Pin 2 =4.35k ohms
Pin 3 = 0 ohms.
The plug (wiring harness) pin to ground (negative) voltage readings (key on) are:
Pin 1 = 12.5 volts
Pin 2 = 5.0 volts
Pin 3 = 0 volts
When I started the car (yeah it runs) with the plug off and checked the voltages again, the only one that changed was:
Pin 1 = 14.3 volts.
I realize this thread seems pretty old, but I just have to thank this forum again and particularly this poster.
2004 BEW three years ago starts slow, idles rough, and when I got my VCDS I see sensor cam shaft position no signal. About to spend 80 bucks and my time, I note the test points. Sensor double the resistance as stated, Wiring harness color code different and Resistance in female side plug, 1 open, 2 correct 3 open and accurate..Key on, 1 no volts, 2 5 volts accurate 3 proper.
Here is what I did to prove the sensor good. Rather than tear out the PCM to trouble shoot the number 1 no volts. I figured there must be an easier way.
Hoping this helps others, I figured with my new toy the VCDS setting at 0.0 I put a very thin needle through the harness wire near pin 1. I cut a wire and with hemostats tied the wire to the needle then to the battery plus. Started car amazingly in half crank, runs smooth and VCDS registered a negative 1.5 so I found this poster to be right on. I suspect I should tweek the cam timing in advance to 0 or .5, but I'll wait till timing belt change and let VW do that. Car is running fantastic at 257K miles. Timing belt next January.
I used a needle not to damage a good wire. I will then use the same needle and hit midway until I get a continuity reading then jump to that point rather than disturb the PCM that is a job in itself. My test points are now held together with tape and wrapped wire to battery.
Thank you my friend and members. Dizilluber