Code Enable Criteria

WARNING: This page is about a different car, the 2002 Isuzu Trooper. However, it is still accessible from the selected car via links, so may be relevant.

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.