H22 - Check For Power At HO2S Harness Connector

- Key "ON", engine "OFF".

- Heated Oxygen Sensor (HO2S) disconnected.

- Measure voltage between KEY POWER circuit and PWR GND circuit at the HO2S vehicle harness connector (refer to schematic). H - Test Schematic

- Is voltage greater than 10.5 volts?

Yes -- Reconnect HO2S. HO2S system OK. Fuel delivery is OK. HO2S sensor may have cooled prior to Engine Running Self-Test. If symptom persists, problem is in an area common to all cylinders, i.e. air/vacuum leak, fuel contamination, Exhaust Gas Recirculation (EGR), Secondary Air Injection (AIR), Manifold Absolute Pressure (MAP), check MAP frequency, ignition system. etc. Return to Diagnostic Routines.

No -- Go to H23.