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

GM
Type:
    Powertrain - Ignition System or Misfire - ISO/SAE Controlled
Description:
    CKP Sensor Circuit Low Frequency Conditions
Cause:
    Engine speed below 4000 rpm, MAF input 5 g/sec or higher, then the VCM detected that the CKP REF duty cycle was over 50%, or that the ratio of High REF to Low REF pulses was less than 1.8