E30 Wiring Cheat Sheet

A quick listing of some important wiring for reference. Updated as time permits.


  1. signal in: Grey/Yellow
  2. ground: Grey/Blue
  3. Intake air temp: Grey/Violet
  4. power (5v): Grey

EGO (o2):

  1. power (12v): Green/Blue
  2. ground: Brown
  3. heater: White
  4. signal to ECU: Black (after C141 it is green)

TPS (M20 — [M50])

  1. Throttle Closed: Brown/Blue — [Ground: Brown]
  2. Ground: Brown — [ECU Signal: Black]
  3. WOT Switch: Brown/Black — [Power 5v: Red/Green]