CODE 44, NON-HEATED O2 SENSOR CKT, LEAN EXHAUST INDICATED (EXCEPT GSi): Notes

ECM supplies a voltage approximately .43 volt between ECM terminals D6 and D7. The heater circuit on the O2 sensor is turned on when engine is running. As O2 sensor heats up, it will begin to send a varying voltage signal to ECM. This voltage will vary between .1-1.0 volts, depending on condition of exhaust gasses in exhaust manifold.

This sensor is like an open circuit and produces no voltage when sensor temperature is less than 600°F (316°C). An open sensor circuit or a cold sensor will cause open loop operation.

1. Code 44 is set when O2 sensor signal voltage is fixed above .280 mV, TPS is more than 3 percent, Codes 21 and 33 are not present, system is in closed loop, coolant temperature is less than 155°F (68°C), and integrator count is not at 128.