HO2S Warm-Up Sensor 1 / HO2S Warm-Up Sensor 2

Scan Tool Range 00:00 to 99:99 MIN:SEC. The scan tool display indicates time to warm-up for each HO2S. The HO25 warm up time is used for the HO2S heater test. The PCM will run the heater test only after a cold start (determined by engine coolant and intake air temperature at the time of start-up) and only once during an ignition cycle. When the engine is started the PCM will monitor the HO2S voltage. When the HO2S voltage indicates a sufficiently active sensor, the PCM looks at how much time has elapsed since start-up. If the PCM determines that too much time was required for the HO2S to become active, a DTC will set. If the engine was warm when started, HO2S Warm-Up will display the value that was stored last time the test ran. If info has been cleared, HO2S Warm-Up will display 00:00.