How-to: Enter DFU mode

CS 737X CDU

  1. Disconnect USB cable from the CDU.
  2. Press and hold the “INIT REF” key and the number “5” key.
  3. Connect USB cable to the CDU.
  4. The backlight flashes, indicating that CDU has successfully entered DFU mode.
  5. Release the “INIT REF” key and the number “5” key.

CS 737X EFIS

  1. Disconnect the USB cable from the EFIS.
  2. Disconnect the daisy chain cable from the EFIS when it is in the home simulator “daisy chain” mode.
  3. Press and hold the “STD” key.
  4. Connect the USB cable to the EFIS.
  5. The backlight flashes, indicating that EFIS has successfully entered DFU mode.
  6. Release the “STD” key.

CS 737X MCP

  1. Disconnect the USB cable from the MCP.
  2. Disconnect the daisy chain cable and DC power cable from the MCP when it is in the home simulator “daisy chain” mode.
  3. Toggle the “A/T ARM” switch to the “ARM” position and hold.
  4. Connect the USB cable to the MCP.
  5. The backlight flashes, indicating that MCP has successfully entered DFU mode.
  6. Release the “A/T ARM” switch.

CS 320N FCU-L/R

  1. Disconnect the USB cable from the FCU-L/R.
  2. Disconnect the daisy chain cable from the FCU-L/R when it is in the home simulator “daisy chain” mode.
  3. Pull and hold the Barometer Reference Selector Knob.
  4. Connect the USB cable to the FCU-L/R.
  5. The backlight flashes, indicating that FCU-L/R has successfully entered DFU mode.
  6. Release the knob.

CS 320N FCU-C

  1. Disconnect the USB cable from the FCU-C.
  2. Disconnect the daisy chain cable and DC power cable from the FCU-C when it is in the home simulator “daisy chain” mode.
  3. Pull and hold the HDG/TRK Selector Knob.
  4. Connect the USB cable to the FCU-C.
  5. The backlight flashes, indicating that FCU-C has successfully entered DFU mode.
  6. Release the knob.