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F21 Code Help – Beginning Brake Test Not Passed

F21 (MMX/MMV): Beginning-of-Run Brake Test Failed

Code Meaning: Occurs if beginning brake test fails. This means slipping was detected during the initial brake test.

Further Information/Troubleshooting Tips:

  1. If your motor is in a place where a lot of dust or residue could build up on the brakes, this may be the cause of slipping when the drive performs this test. Try running the drive in test mode (U49) to let the brake set a time or two and clear off any potential dust/residue. Watch this video if you are not familiar with how to run the drive in test mode.
  2. Perform diagnostic/maintenance procedures on your motor brake per the manufacturers specifications. Tighten, adjust or fix the brake as necessary to eliminate all possible sources of brake slippage.
  3. If you have performed the above steps and are still seeing the F21 code, Consult PE® for adjustment help.