Can anyone tell me if this looks like a bad pcm? Car is a 2012 Chevy sonic, has random misfire codes. Will run smooth then out of blue runs terrible, misfires will be on diff cylinders, sometimes cyl 2, other times cyl 1, sometimes 2 and 3 at same time according to scan tool misfire counter.I took a sample of injector control signal, sometimes it has an extra pulse which is real short. This is just cyl 4. I’m kinda new to using oscilloscope FYI.
Hi.
This mode of operation of the fuel injector control driver is not a malfunction.
This is the ECU's response to the need to stabilize the crank-shaft rotation.
You need to look for the cause of uneven engine operation.