Oxygen Sensor (O2S 1)

Wiring Diagram:

DESCRIPTION
The fuel control Oxygen Sensor (O2S 1) is mounted in the exhaust pipe below the exhaust manifold, where it can monitor the oxygen content of the exhaust gas stream.

OPERATION
The oxygen present in the exhaust gas reacts with the sensor to produce a voltage output. This voltage should constantly fluctuate from approximately 100mV (high oxygen content lean mixture) to 900mV (low oxygen content rich mixture). The oxygen sensor voltage can be monitored with a scan tool. By monitoring the voltage output of the oxygen sensor, the ECM/PCM calculates what fuel mixture command to give to the injectors (lean mixture-low O2S voltage=rich command, rich mixture-high O2S voltage=lean command).

Legend

1. Crankshaft Position Sensor
2. Engine Coolant Temperature (ECT) Sensor
3. Intake Air Temperature (IAT) Sensor
4. Manifold Absolute Pressure (MAP) Sensor
5. Engine Control Module (ECM) / Powertrain Control Module (PCM)
6. Circuit Opening Relay
7. EFI-HTR Relay
8. Heated Oxygen Sensor 2(HO2S 2)
9. Oxygen Sensor (O2S)