Ford
Type:
    Powertrain - Ignition System or Misfire - ISO/SAE Controlled
Description:
    Knock Sensor 1 Circuit Performance Conditions
Cause:
    Engine running, then the PCM detected a KS signal outside the calibrated value This code may set at key on if the KS signal is more than 0.5v

Generic
Type:
    Powertrain - Ignition System or Misfire - ISO/SAE Controlled
Description:
    Knock Sensor 1 Circuit Range/Performance

GM
Type:
    Powertrain - Ignition System or Misfire - ISO/SAE Controlled
Description:
    Knock Sensor Performance Conditions
Cause:
    No PCM codes set, ECT input more than 140°F, engine runtime over 2 minutes, engine speed over 2200 rpm, throttle angle over 6%, then the PCM detected the Knock Sensor AC voltage input was less than a minimum value