Code 44 - O2 Sensor (Lean Fuel Mixture): Notes

The ECM supplies a voltage of approximately .45 volt between terminals D6 and D7. Oxygen sensor varies voltage from one volt (rich exhaust)to .1 volt (lean exhaust). The sensor acts like an open sensor circuit and produces no voltage when exhaust temperature is less than 600°F (316°C). An open sensor circuit or cold sensor causes open loopoperation.

1. A Code 44 is set when oxygen sensor signal voltage on circuit No. D7 remains less than .2 volt for 50 seconds and system is operating in closed loop.