Hi guys,

Had the above vehicle in earlier with 'spanner' light illuminated.
P0340 Camshaft Sensor Incorrect Signal.

Check power & ground, both fine at 12.6V & 5.09V
Scoped signal, looked ok to me, so cleared the code.
Code cleared KOEO but returned immediatly with engine start.

Scoped cam V crank and got same capture as Lee's Astra H Z18XE in Autoscope forum.

Replaced Cam sensor (genuine) and re-scoped, this produced a slightly different waveform.
Obviously, I am erring to the latter one being correct as the code no longer returns and car runs fine.

My question is .. Can someone confirm to me that the second capture is correct. Or not, as the case may be.
Without seeing a capture before & the two being very similar to each other I am not 100% certain & it's bugging me.

Almost forgot, as the two were so similar, I also checked cam belt timing & found it to be correct with no undue slack

Thanks, Tony.


First capture.


Capture new Cam sensor.

1st image is a good example and the second is when the cmp sensor signal dropped out.

Edit:

Just seen Dave Harney's Cam/Crank sync .. .. Thank you Dave.

Well, it appears that everybodys sync is between the 7th & 8th tooth except mine

Should I have a worn keyway, it's strange that the signal stays constant even with revving the engine, I would have expected some movement whilst doing that ??

Anyhow, hopefully all will become clear when timing belt is replaced.

Thanks to Lee, James and Dave for your help Guys.

Cheers, Tony.