PicoScope 7 Automotive
Available for Windows, Mac, and Linux, the next evolution of our diagnostic scope software is now available.
What is causing all this noise?
What is causing all this noise?
Any idea what is causing all this noise in all 3 waveforms? I checked my ground, direct to the battery multiple times and it was good. I was backprobing at the PCM and I believe I had a good connection there as well.
This is a screenshot of the waveform, saved in my google drive. All help greatly appreciated!
https://drive.google.com/file/d/1_jWg5l ... sp=sharing
This is a screenshot of the waveform, saved in my google drive. All help greatly appreciated!
https://drive.google.com/file/d/1_jWg5l ... sp=sharing
Re: What is causing all this noise?
Although the Pico test leads and the PicoScope itself are screened the wires in the wiring loom of the car itself are not screened (to save cost and weight).
The wires from the cam & crank sensors probably have other noisy signals running alongside them in the loom (ignition and injectors) causing these spikes.
Inside the ECU inputs from sensors are filtered to remove this noise. You can do the same to "clean up" the waveform using the filters built into PicoScope https://www.picoauto.com/library/training/filtering
Often though its best to start with the filters off - sometimes excessive noise can be due to a fault so getting used to what is normal is good experience.
The wires from the cam & crank sensors probably have other noisy signals running alongside them in the loom (ignition and injectors) causing these spikes.
Inside the ECU inputs from sensors are filtered to remove this noise. You can do the same to "clean up" the waveform using the filters built into PicoScope https://www.picoauto.com/library/training/filtering
Often though its best to start with the filters off - sometimes excessive noise can be due to a fault so getting used to what is normal is good experience.
Re: What is causing all this noise?
Thank you.
Re: What is causing all this noise?
Can we go a little more in depth?
Background. Vehicle came in with intermittent no start. P0339 Intermittent crank signal
I wanted to play with the scope.
Hooked it up. Now when the car was running well, I got all this noise, BUT, when the car began to run like shit, and the CKP began to break down on the scope, the noise disappeared from all 3 channels!
So was the CKP the cause of the noise all along?
Here again is a screenshot, stored on my Google Drive. https://drive.google.com/file/d/1G-LQQh ... sp=sharing
And here are the 2 waveforms, so you can open then up yourself
This first one is with no CKP breakdown, and noise. My foot is on the gas pegged at the neutral rev limiter (about 3500rpm)
https://drive.google.com/file/d/10eJwUv ... sp=sharing
And this second where is where the CKP is breaking down, Again at 3500rpm to induce the breakdown.
https://drive.google.com/file/d/14uMQOB ... sp=sharing
The result of the CKP breakdown is the engine falling on it's face, and almost stalling till I reduce throttle. If I don't reduce, it will stall.
All I care about is the noise, and making sure I didn't make a mistake myself in setup.
Background. Vehicle came in with intermittent no start. P0339 Intermittent crank signal
I wanted to play with the scope.
Hooked it up. Now when the car was running well, I got all this noise, BUT, when the car began to run like shit, and the CKP began to break down on the scope, the noise disappeared from all 3 channels!
So was the CKP the cause of the noise all along?
Here again is a screenshot, stored on my Google Drive. https://drive.google.com/file/d/1G-LQQh ... sp=sharing
And here are the 2 waveforms, so you can open then up yourself
This first one is with no CKP breakdown, and noise. My foot is on the gas pegged at the neutral rev limiter (about 3500rpm)
https://drive.google.com/file/d/10eJwUv ... sp=sharing
And this second where is where the CKP is breaking down, Again at 3500rpm to induce the breakdown.
https://drive.google.com/file/d/14uMQOB ... sp=sharing
The result of the CKP breakdown is the engine falling on it's face, and almost stalling till I reduce throttle. If I don't reduce, it will stall.
All I care about is the noise, and making sure I didn't make a mistake myself in setup.