1980 BMW 633CSi Automatic TransFACTORY OEM SERVICE PROCEDURE

Control Module Ground Check

Disconnect connector at control module. Turn ignition switch "ON". Connect voltmeter positive lead to terminal 31 of control module (not harness). Connect negative lead to ground. Reading should be zero (0) volts. Check module ground wire and repair as necessary if reading is not zero (0).

Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.