OK so I purchased a COP Paddle Probe to use with my U-Scope for troubleshooting a friends misfire issue( on a Honda). I was going to see what my 2006 Prius COP signals looked like using this probe. I put the car in maintenance mode so the engine runs all the time. Using the U-scope and paddle probe and the engine running I get no secondary signal on the U-scope( tried different grounds on engine for probe ground connections) I used the scope and paddle probe on my old truck that has HEI and I get a signal fine so the scope and probe work. I guess I asking any Toyota mechanics out there why can't I pickup a coil signal on my Prius engine while it's running.
Never mind figured out that some COP coils are insulated very well and these paddle probes won't work for picking up a signal.
On most cars, the engine is the negative of the alternator, so very well connected to the frame ground. As the prius has no alternator attached to the engine via belts, it may well be that the Prius engine is more isolated than the norm.
