How to Invoke the Bootload Mode

If the MPLAB X IDE or MPLAB IPE cannot communicate with the debugger, the debugger may need to be forced into bootload mode (download new firmware). Some possible reasons could be the following:

Perform the following steps to force the debugger into bootload mode:

  1. 1.Disconnect the Micro-B USB cable from the debugger.
  2. 2.Press down on the MPLAB PICkit 4 logo and hold while plugging in the Micro-B USB cable. The light strip flashes purple. Continue pressing the logo until the light strip stops flashing and changes to steady on purple. You are now in bootload mode.
  3. 3.Try to reestablish communication with the MPLAB X IDE or MPLAB IPE. If successful, the latest firmware is downloaded. When complete, the LED is steady on blue and the debugger is ready for operation.