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Wiring Reference

BMW uses a consistent wire color coding system across models:

ColorAbbreviationTypical Use
RedRTIgnition-switched power (KL15)
GreenGNBattery-direct power (KL30)
BrownBRGround
BlueBLSignal/data wires
YellowGELighting circuits
WhiteWSVarious signals
GrayGRCAN-bus high
BlackSWCAN-bus low, ground
VioletVISensor signals

The E46 uses K-Bus (body) and D-Bus (diagnostic) networks:

  • K-Bus: Body electronics (doors, windows, IHKA, radio) — single wire
  • D-Bus: Diagnostic communication — OBD-II port
  • PT-CAN (later models): Powertrain CAN for DME/transmission
PinFunction
2J1850 Bus+
4Chassis Ground
5Signal Ground
6CAN High (ISO 15765)
7K-Line (ISO 9141-2)
8K-Line (BMW specific)
14CAN Low (ISO 15765)
16Battery Power