Suitable for engines : 184hp, 193hp, 163hp M57D30/D25 306D1 Simplified wiring includes: Fuel pump relay + fuse Ecu 40pin plug (body side 4th plug to ECU) Gas pedal plug Obd2 plug Out for +12V on switch (key position 1) Out for ground (earth ring) Out for RPM Out for alternator lamp Out for oil pressure lamp Out signal for BMW OEM electric fans Note: Wirings may have differences from the photo shown but same placement.