The disease has caused her immune system to 'go haywire'. [=to stop working properly]
The stock market has 'gone' completely 'haywire'.
The old radio 'went haywire'.
(..) Can you see me now, Spider-Man? It's time to meet our destiny. Tower, we're experiencing some kind of electrical disturbance. Instruments are going haywire, radar is down. We're flying blind out here, do you copy? Tower, repeat, we're "standby" only, what is happening? Time to impact? (..)2014 The Amazing Spider-Man 2