Signal generator fun

Caleb Technician Indiana Posted   Latest  
2018 Chevrolet Traverse LT 3.6L (W LFY) 9-spd (9T65)
Known Good Test Vehicle

So just a fun little look see at a signal generator I recently built. Not going to go into the construction as much as displaying its functionality. I have a 12v to 5v convertor inside the box. Then I have the signal generator mounted in the lid. Ive wired it too where it can output a 0-12v or 0-5v PWM signal. I also wired a 5v supply output so I have a ready 5v anytime I might need it for testing.

diag​.​net/file/f6sek295a… ​ 

So I was using it to take the place of the MAF signal on a 2018 Traverse. Its a 0-5 volt square wave that generates a hertz signal based on the volume of air flowing over it. Here we are at 2170 hertz on the signal generator with the output connected to the MAF signal wire at the MAF connector with the MAF unplugged. 


Here is the MAF scan data with the car running, matches the signal generator almost perfectly.


Now its bumped up to 3840 hertz.


Again the scan data matches

diag​.​net/file/f2z2ne6ti… ​.

Here is a few more scope captures with the tool. 



​This last one is 100k hertz.


diag​.​net/file/f567fo6gk… ​ 

Im sure I will find many uses along the way for it. Actually used it the other day to simulate the feedback signal from the alternator connector on a 2009 Pontiac G8. It put a perfect 0-100% data on the scan data in 1% increments unfortunately I didnt take any pictures because I was in a hurry,but it verified the wire and the ECMs ability to interpret the signal.

Joel Diagnostician
Joel Default

are you willing to sell some of those? I will be interested to buy it

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Caleb Technician
Caleb Default

Hmm guess I never thought of that. I might be.

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