Code Enable Criteria

Following conditions must be met for DTC diagnostic test to run:

• Engine coolant temperature is more than 140°F (60°C).
• Engine is operating in closed loop.
• Engine has been running at least one minute.
• Canister purge duty cycle is 2 percent or more.
• Engine speed is between 1500 and 3000 RPM.
• Mass air flow is between 9 and 42 grams/sec.
• Above conditions are present for 3 seconds.
• Ninety seconds after closed loop operation has been achieved, PCM monitors HO2S as it switches above and below 450 millivolts. If less than 23 rich-to-lean and lean-to-rich switches are detected, DTC P1153 will set.