Your knock sensor isn't sending proper signals to the engine computer, like a smoke detector with a dead battery that can't alert you to danger. The engine can't adjust timing properly to prevent harmful detonation.

The ECU monitors the knock sensor's voltage signal to detect engine detonation (abnormal combustion). When detonation occurs, the sensor generates a signal that triggers ignition timing retard. If the signal is absent, too weak, or erratic, the ECU cannot compensate for knock.

Voltage & Parameter Thresholds