VNH5019 Fault Detection Logic

I’ve been running into issues where I’m unable to command my motor using a VNH5019 Dual Driver Sheild after a fault was detected and the motor driver was power cycled.

This is what I’m seeing:

  • Motor driver operates as expected and is able to power a motor
  • A fault is detected by querying the ENA/DIAGA pin
  • Motor driver is power cycled
  • No fault is detected but the motor driver is unable to command the motor
  • Motor driver magically starts working after left alone for 10-15 mins

I’m curious as to what the fault detection logic is. For example, if the fault was due to overheating, will the fault not be detected when the motor driver is powered on and is already above the max temp limit?


The ENx/DIAG pin should still trigger even if the fault is present when the driver is powered on. Could you post more details about your setup? What motors are you using? How are you reading the ENx/DIAG pins? Do you know what is causing the initial fault?


Hi Claire,

Thanks for responding!

My setup is as follows:

Please let me know if you would like any more information

Does the original fault happen consistently? For example, after a certain time period or way of moving the motors? Are you using both motor channels and reading the faults form both? What is your 12V supply and is there anything else in your enclosure?