Hybrid Hardware and Monitor Operation

WARNING: This page is about a different variant/trim than selected.

The hybrid vehicle exhaust system uses two separate HO2S. The front HO2S is a universal HO2S and is the primary fuel control sensor. This sensor is the first HO2S in the exhaust stream and is referred to as the front or stream 1 HO2S. The last HO2S downstream in the exhaust system is used to monitor the catalyst and is referred to as the rear or stream 2 HO2S. For additional HO2S information, refer to the HEATED OXYGEN SENSOR (HO2S) MONITOR .
Typical monitor entry conditions:
- minimum 5 seconds since start-up at 21°C (70°F)
- engine coolant temperature is between 66°C - 110°C (150°F - 230°F)
- intake air temperature is between -7°C - 82°C (20°F - 180°F)
- time since entering close loop is 30 seconds
- inferred rear HO2S sensor temperature, minimum of 427°C (800°F)
- exhaust Gas Recirculation (EGR) is between 0% - 16%
- part throttle, maximum rate of change 0.24 volt/0.05 sec
- vehicle speed is between 56 - 129 km/h (35 - 80 mph)
- fuel level is greater than 15%
- air mass is between 11 - 26 g/sec (1.5 - 3.5 lb/min)
- engine speed is between 1,000 - 2,500 RPM
- engine load is between 20 - 60%
The DTC associated with this test is DTC P0420. Because an exponentially weighted moving average algorithm is used to determine a concern, up to six driving cycles may be required to illuminate the MIL during normal customer driving. If the KAM is reset or the battery is disconnected, a concern illuminates the MIL in two drive cycles.