I am new to using a scope so I am hoping for some guidance on interpretting these waveforms from someone with more knowledge of these things.

This car has a regular misfire and drops onto 3 cylinders a few minutes after starting from cold with fault code: P0201 Injector 1 voltage low.

This first trace is when there is no fault present.

Channel A: Injector Supply
Channel B: Injector Control Circuit
Channel C: Injector Current



This trace is the moment when the vehicle misfires.



It would appear to me that when the fault happens and the PCM grounds the injector there is an initial spike to around 25V on the injector supply which then immidiately drops to 0V

From my limited knowledge I am thinking that there is a internal fault with the PCM related to the capacitor for Injector 1. (Is there an individual capacitor for each injector?)

I would be gratefull for any help or guidance on making sense of these waveforms.

Please excuse any spelling mistakes, cant get spellchecker to work.
Thanks

Tommy