# 16725 - Camshaft Position Sensor (G40): Implausible Signal, So far not fixable



## jmtyndall (Jan 20, 2012)

Car won't start except after several attempts. When it does run, it feels a bit sluggish, but doesn't run rough or anything. MIL is on and only showing code: 16725 "Camshaft Position Sensor (G40): Implausible Signal ". Put a new Cam Sensor and a new Crank Sensor in it and visually checked the wiring as far as I could, still having the same problem. So I checked the timing and it is also good. 

Took it to a VW specialist who recommended I go to the dealer for a pinout test, as he had checked my sensors and the timing and it all looked good. When I got to the dealer they refused to do a pinout test and started by checking the codes. After that, they checked the cam tensioner, and said it was good, and that the timing was dead on. I prompted them again to do a pinout test and they refused, claiming it needed a new cam sensor, new crank sensor, and timing belt change before they could perform any further diagnostics, despite the fact that those two sensors are both brand new, and their tech had already tried a different cam sensor, with no change in symptoms. 

I'm wondering if there is a way I could test the wiring myself with a DMM. I haven't been able to find a test procedure as of yet. A nudge in the right direction would be greatly appreciated. 


ETA: I have checked the connector at the Cam Sensor. Pin 1 to Pin 3 reads correct at 4.9V, however Pin 2 to ground reads 12V, and that seems wrong, as it should be signal to the ECU, and, should seem to be 0v if unplugged. I'm going to try backprobing it later and see if I get a better reading. 
Thanks, 
Josh


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## jmtyndall (Jan 20, 2012)

My repair manual states that a backprobe of pin 2 should yield voltage between 0v and 10v, I'm getting a square waveform from 0v to 12v turning the motor by hand. Not sure what the cause could be. Next time I get out there I'll test the resistance of the wiring from the ECU to the cam sensor, but I'm not sure what values I should be getting. Other than that it seems the last thing to check is the wheel that it reads off of, but I'm not sure what I would be looking for


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## rstolz (Jun 16, 2009)

you 'd be looking for contamination, warping (bent), or free play, anything that might disrupt normal current induction.


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## Gooshpoo (May 15, 2013)

I replaced my impulse sensor recently and i thought it didn't fix my problem i still had engine lights on. I got a obd Bluetooth scanner from ebay and got torque pro cleared the codes and it fixed it so maybe you just need to clear the codes .


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## silverstonevr (Aug 20, 2011)

did you figure out this issue?
i have the same code. Implausible signal to sensor...


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## groggory (Apr 21, 2003)

Would you mind making a video of your back probing procedure? I think it would help a lot of people


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## Chickenman35 (Jul 28, 2006)

groggory said:


> Would you mind making a video of your back probing procedure? I think it would help a lot of people


You want to get of video of WHAT???  You may want to reword that.... :laugh:


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## groggory (Apr 21, 2003)

Chickenman35 said:


> You want to get of video of WHAT???  You may want to reword that.... :laugh:


Don't judge me


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## Chickenman35 (Jul 28, 2006)

:laugh:


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