- 30V transient diode for high-voltage flyback
for extremely fast injector closing (either inside controller case or in loom). Important: with high voltage flyback you MUST disable injector PWM (injpwm peak time=25.5msec, duty=100%) :
prefer highZ injectors (so no series resistors needed). If you insist on lowZ injectors (under 5.2 Ohm), you will need to use series power resistors (usually 4.7 Ohm or 6.8 Ohm 50W see "output drivers" category).
Unidir: striped-marked cathode towards the controller mainboard. Anode toward the injector common +12V. (the direction of the bidir does not matter so the bidir has no stripe. The unidir is said to work slightly better).
- 18V unidirectional transient diode: used on +12V supply (eg. D22 on genboard v3.8, striped marked cathode goes to +13.8V) to provide some protection for expensive equipment from supply spikes (from alternator, circuit breaker, .... CAN NOT protect from missing or insufficient grounds, welding or accidental removal of ECU while powered up or harness-accidents). It is a must when circuit breaker switch is installed. Best to always install one in the loom (this is stronger than the SMB transient suppressor inside v3.x and easier to replace). Even with this, strong and agressive starter aid is not recommended
- BY399 3A fast diode: solenoid/relay flyback when 30V transient diode is used for flyback ; or protection of LEDs in timinglight circuit
- resistor (0.1 Ohm 5W)