how does a power transistor work. i know that it amplifies the signal from the ecu to the coilpacks, but how? I am working on a car and it will not spark. I havent yet checked tha CAS, but the ecu threw an ignition code but not a CAS code. What kind of an ignition signal does the ecu output before the transistor? Anyone?
the power transistor is just like a solid state relay. It takes a small signal from the ECU to trigger a “switch” and then the transistor allows power to flow in this case it goes to the coils and provides power for the primary side of the coil.
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wtf?
AHAHAHAHAHAHAHAHAAaa
but there is an ecu signal in, signal out and ground. does it act on the ground side of the coil. because i have power at the coil. i have ground at the coil. but when i put a test light on the signal wire, i get nothing. they tell me to do this in the manual, but i dont see where the power would come from, beacuse there really isnt any power coming into the ptu…
maybe i could use your logic probe to check it vs the FSM, but i ran the test with a test light and battery and it didnt match, but neither did the replacement ptu that i tried… unless they are both bad…
do you have a 300zx? because i have the same problem with a 90 300zx, i order the power tranisitor unit and hopefully it will help. I was also told at the dealership that about 7 years ago they replaced a shitload of these units. mine is going in tomorow and ill let u know if it helps. I am having trouble on cylinder 4, i tested all others by plugging a spark plug into the end and groundng it on the motor and i got spark on it with another cylinder’s plug, if its not the ptu then its gotta be the ecu or a short in the wire i think, i guess ill ffind out tomorow.
No you know what you are right i forgot there is power to the coils at all time on those engines. the transistor then completes the ckt for each individual coil.