Audi 3B engine is similar to VemsAudiAan, so procedures are the same, but
- the [relevant] pinout (file, or spreadsheet column) must be used due to pin differences
- eg. flyback is same mot55/pin37
- but trigger pins are different
3B relay
MembersPage/PeterJensen/AudiSwiring
3Bpin37 is flyback (EC36pin23). Injectors are supplied from the ECU via this pin (3B is different from the AAN/ABY/ADU in this respect).
3B ECU internal relay (standard, unless requested otherwise):
Relay coil powered from:
- mot55/27 +12V when ignition is ON (EC36/25 ECU supply pin)
- GND
Relay output "normally open" (closed when ignition is ON = ECU is powered up)
- 3B MOT55/pin18 (VBATT constant +12V, even alive when ignition is off)
- 3B MOT55/pin37 (EC36pin23). Injectors of the 3B harness are supplied from the ECU via this pin.
The idea is NOT to draw much (2A+) current from 3Bpin27 because we fear that might damage the ignition switch (we didn't try or measure though).
Ignition output(s)
- Either just 1 igncoil can be used, with distributer
- or custom ignition output mapping for passive coils, or active coils
- Audi POS power output stages + passive coils together are effectively "active coils", because the ECU can drive with logiclevel positive-active signal.
Eg. 4 stepper outputs (possibly with 100 Ohm protection resistors) and a logiclevel ignition output on an extra (eg. EC10 flyingloom) connector possible for 5 COPs if requested.
Fuel pressure regulator
- target pressure might differ from AAN
- eg. 3.5 bar instead of 4 bar FP means sqrt(4 / 3.5)=1.069 so 6.9% (7%) more fuel injection PW required, consider this when tuning (or when adapting borrowed tables)
- remember the first 1.4msec of the fuel pulsewidth is just to get it open