Code Enable Criteria

• Engine speed is less than 3200 RPM.
• Start-up ECT is 39-174°F (4-79°C).
• O2S1 is greater than 600 millivolts for greater than 2 seconds.
• IAT is greater than 32°F (0°C).
• MAP is greater than 20 kPa.
• Ignition voltage is 11-18 volts.
• Traction control is not active.
• Command air/fuel ratio is 12-14:1.
• Calculated airflow is 8-19 grams/second.
• No 5-volt reference, ECT, EGR, fuel trim, IAC, IAT, MAP, misfire, O2S1 or TP sensor DTCs are set.

DTC sets when AIR system is being commanded on during a cold start and O2S1 signal does not indicate a lean condition (voltage less than 300 millivolts) for a minimum of 2.5 seconds out of a 10 second test.

On vehicles built after VIN 1Z200000, if air pump does not run long enough to obtain accurate test results, PCM may run up to 5 independent tests if a test fails or does not fully run. PCM must see O2S1 voltage go less than 300 millivolts for at least 1.5 seconds out of a maximum 6 second test. PCM will wait 20 seconds between each test if another test is going to run.

To run active test:

• ECT is greater than 167°F (75°C).
• Commanded air/fuel ratio is 14.7:1.
• Engine is at idle for at least 4 seconds.
• Short Term Fuel Trim (STFT) is 122-134.