Generic
Type:
    Powertrain - Ignition System or Misfire - ISO/SAE Controlled
Description:
    Crankshaft Position Sensor "A" Circuit Range/Performance

GM
Type:
    Powertrain - Ignition System or Misfire - ISO/SAE Controlled
Description:
    Crankshaft Reference 18X Circuit Conditions
Cause:
    Engine running with 3X REF signals present, then the PCM detected that it did not receive any 18X reference pulses in one engine cycle (720 degrees of crankshaft revolution)