October 30: LEMON manuals on a temporary server, it is slow and having issues, download the manuals you need! Later in November we will switch back to the fast server.

When Monitored

This diagnostic runs when the following conditions are met:

Battery voltage between 10.5 and 15.75 volts.
With the O2 Sensor Heater commanded on.
The O2 Sensor Heater circuit high fault is not active.