Code 44: Lean Exhaust Indication: Notes

The ECM supplies a voltage of about .45 volts between terminals No. E14 and E15. If measured with a 10-megaohm digital voltmeter, this may read as low as .32 volts. The oxygen sensor varies the voltage within a range of about one volt. If the exhaust is rich, voltage will go down about .10 volt. If exhaust is lean, voltage will go up about .20 volts. When the sensor temperature is below 600°F (360°C), the sensor is like an open circuit and produces no voltage. An open sensor circuit, or cold sensor, causes "open loop operation".

1. Code is 44 is set when oxygen sensor signal voltage on circuit No. 412 remains below .3 volts for 50 seconds or more and system is operating in "closed loop".