When Monitored

Engine running, the O2 Sensor 1/1 at operating temperature, pump cell active. When the PCM detects a circuit has fallen outside the allowable range during either the cold startup test or during O2 Sensor closed loop operation, a Hot test  is initiated. The O2 Sensor is turned off and a 20 second delay timer is started. Once the timer expires, the hot test diagnostic will be performed.