If you are using a low side output on the ME100 or ME221 to drive an inductive load (such as a VVT or Idle solenoid) you should install a flyback diode across the two wires that go to it. Use a 1N4001 diode, with the striped end Tee'd into the 12v supply, and the other end Tee'd into the LS signal line.


This applies to any generation of ME Wire-In Engine Management Systems.


Note if you are driving simple/slow acting outputs such as relays for fuel pump, cooling fans, shift lights, etc, then you do not need to install these diodes.


1n4001 diodes can be found on electronics suppliers such as RS Components. RS number 628-8931