ECM DTC EO17: Left O2 Sensor Not Ready: Description

The ECM provides a 0.45-volt reference to the oxygen sensor on circuit No. 412. When the sensor warms up, it will cause the 0.45-volt reference to vary based on oxygen content in the exhaust gasses. A lean mixture will cause the voltage to decrease. A rich mixture will drive the voltage above .45 volts. If during the test conditions described, the oxygen sensor voltage does not vary, the ECM assumes that the oxygen sensor can not respond and will set Code EO17. Possible causes for EO17 are an open circuit No. 412 or 413, short to voltage on circuit No. 412 or 413 or oxygen sensor is unable to respond.