Doubts with Relays

Hello friends! I have a question... In this chapter, the activation of the injector and ignition relay come from the relay that feeds the ECU. My query is the following, when deactivating the injection and ignition relay does it not return an inductive peak to the same joint where the ECU power supply is connected? Or are you using Relays with diodes or capacitors?

With a traditional relay, with an energised coil pulling on the main contact, there will be a very small inductive spike as the field collapses, however, this is very small and not something to worry about. With solid state relays, even that doesn't happen.

If you disconnect the fuel and ignition power relays (if used) before powering up the ECU, even that tiny spike will be avoided.

Oh, depending on the ignition setup you have, if you disconnect the relay while the coil(s) is (are) in a powered state, you may get a spark from the output as the field collapses, so don't have your body in contact with the high voltage wiring just in case.

Thank you very much Gord!