Pcm Code EO17, Left Oxygen Sensor Not Ready: Action:

PCM turns on SERVICE ENGINE SOON light and closed loop is disabled. When warm, a properly operating oxygen sensor will drive the PCM's .45-volt reference signal lower (less than .45 volt) to indicate a lean mixture, and higher (greater than .45 volt) to indicate a rich mixture. If under test conditions, if the oxygen sensor does not vary from the cold or not ready voltage, PCM assumes sensor cannot respond to air/fuel mixture changes and sets a Code EO17. Possible causes of setting Code EO17 are:

• Open in circuits No. 912 or No. 413.
• Short to voltage on circuits No. 912 or No. 413.
• Oxygen sensor that cannot respond.

1. A voltage of .42-.48 displayed is a reference voltage from the PCM. Oxygen sensor must generate .15 volt greater than the .45 reference to register a cross count in the PCM.
2. The PCM compares voltage on circuit No. 912 to the ground voltage on circuit No. 413. It is essential that oxygen sensor ground and PCM ground on terminal E15 indicate good continuity (no voltage difference) with engine running.