Principle of Operation

2006 BMW 750LiSECTION Principle of Operation

The starting sequence of the EWS III (3.3) is as follows:

(Same as EWS III (3.2)

  • The key is inserted into the lock cylinder and switched "ON". The EWS III (3.3) control module is powered through KL R and sends a 125kHz AM signal to the ring antenna. The AM signal induces voltage in the key coil and powers up the transponder.
  • Powered up, the key transponder sends the key identification code to the EWS III (3.3) module. The EWS III (3.3) module verifies the key identification code and checks to see if the key is enabled. If the key is correct and enabled, a password is sent to the transponder over the 125kHz AM signal through the ring antenna.
  • When the transponders accepts the password, it releases the changing code which it received from the EWS III (3.3) module during the last start-up operation to the EWS III (3.3) module via the ring antenna.
  • The EWS III (3.3) module compares the changing code received from the transponder with the code stored in its memory and if they match the process is allowed to continue. The EWS III (3.3) module looks at the other inputs for correct status (e.g. Code function not active, Transmission in P or N or clutch depressed, engine speed below specified RPM) and energizes the internal relay to begin starter operation.
RENDER: 1.0x

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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.