P0418 CADILLAC Secondary Air Injection Pump Relay Control Circuit

Possible causes – Faulty Air Pump inoperative– Air bypass solenoid harness is open or shorted– Air bypass solenoid circuit poor electrical connection When is the obd code mean? If the fault detection circuit senses a voltage other than what the Powertrain Control Module (PCM) is expects, the fault line status changes causing the code P0418…