2008 accord with intermittent crank signal code

Hello everyone.

So the crank sensor has been replaced a few times even with the factory one (OEM). And has good power (5v) and good ground all under load. I dont remember the code number.

And this is what the signal looks like. Have any of you seen this before, because when i give gas the amplitude diminishes and the signal gets round instead of a good square waveform. 

I still think is a sensor issue, need same help. 

Thank you.  

fctnunes, I can see that a filter is applied to channel D in your capture:

 

Does turning the filter off change anything? Because, aside from the rounded edges, your signal seems to have the right frequency and amplitude. 

Are you getting P0335? When does the fault set? 

That was my bad, yes the filter was doing that. The code is the p0339.
The code comes on right after you starter it up after a few miles of driving. I see same spikes on the sensor but don't know if that is the scope or the sensor

fctnunes wrote:

That was my bad, yes the filter was doing that. The code is the p0339.
The code comes on right after you starter it up after a few miles of driving. I see same spikes on the sensor but don't know if that is the scope or the sensor

Have you seen this TSB?

 

You noted that the fault comes back after startup, which very neatly matches what the TSB describes. You can check your existing PGM-FI calibration against the TSB and see if a reflash is available.

Even if a reflash is available, I'd still consider replacing the starter and battery. It's been my experience with this fault code that there's something about slow (or uneven) cranking speed that upsets the P0339 monitor.