Forum » EFI Tuning Fundamentals » Examples please

Examples please

EFI Tuning Fundamentals

Forum Posts

Courses

Blog

Tech Articles

Discussion and questions related to the course EFI Tuning Fundamentals

= Resolved threads

Page 1
Author
201 Views

Why would i switch an input to read ground when active and thus require the pull up. An example would be great. thank you.

The reason is because that's the way the integrated circuits (chips) inside the ECU work. The logic inside the chips find it easier to detect a ground connection, than detect a voltage, because then you need a voltage reference to compare with. Resistors are cheaper than comparators. Many inputs can have internal pull-up resistors so all you need to do is switch between the input and ground.