Code Enable Criteria

• Engine is running.
• HO2S12 is in closed loop.
• Fuel level is more than 10 percent.
• Calculated catalytic converter temperature is less than 1724°F (940°C).
• Commanded air/fuel ratio is 14.7:1.
• Battery voltage is more than 11 volts.
• No EGR or EVAP DTCs are set.

DTC sets when HO2S12 voltage is less than 40 millivolts for more than 80 seconds.