Circuit Description
WARNING: This page is about a different car, the 2000 Pontiac Firebird, 2000 Chevrolet Corvette, and 2000 Chevrolet Camaro. However, it is still accessible from the selected car via links, so may be relevant.
PCM provides about 0.45 volt reference to HO2S. HO2S sensor signal voltage varies from about one volt when exhaust is rich to about 0.1 volt when exhaust is lean. When ignition is turned on, battery voltage is supplied to HO2S heater to provide for faster sensor warm-up, thus allowing sensor to become active in a shorter period of time. PCM reads amount of time necessary for sensor to become active after start-up. If PCM determines that too much time was required for HO2S to become active, DTC will set.
For duplication of DTC, ensure:
- DTCs P0101, P0102, P0103, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0200, P0335, P0336, P0351-P0358 or P1258 are not set.
- IAT and ECT sensor temperatures are less than 122°F (50°C) and are within 46°F (8°C) of each other at start-up.
- Ignition voltage is 10-18 volts.
- AIR, EGR and catalyst diagnostics are not active.