Component

HEATED OXYGEN SENSOR (HO2S)-(RH AND LH)

CAUTION: Use ONLY a high impedance Digital Volt Ohm Meter (DVOM) when testing components on computerized vehicles.
Be sure the voltmeter is set to read VOLTS only (not ohms). Be sure external voltage is not applied to the sensor lead, as damage to the sensor may occur.

x�]$Circuit Diagram:

NOTE: Refer to circuit diagram for HO2S test connections.

FUNCTIONAL TEST
1. Make sure the vehicle is at normal operating temperature. Run the engine at 2000 RPM for 3 minutes with the transmission in PARK (A/T) or NEUTRAL (M/T).
2. With the engine Off, connect the negative terminal of the voltmeter to engine ground. Set the meter to 2 Volts DC. Disconnect the Oxygen Sensor lead. Connect the positive lead of the voltmeter to the Oxygen Sensor.
3. Start the engine and increase engine speed to 2000 RPM.
4. Verify that the voltage fluctuates between 0.2 - 1.0 Volts when accelerating and decelerating.
- If sensor voltage fails to vary according to the test steps above, replace the defective sensor(s).
- If test results are OK go to step 5.
5. Reconnect Oxygen Sensor(s) and clear codes.

OXYGEN SENSOR HEATER TEST
1. Disconnect the Heated Oxygen Sensor connector.
2. Measure the resistance between the heater terminals.

Resistance: 2 - 5 Ohms at 2O°C (68°F)
Hot to warm resistance: 5 - 30 Ohms

3. If not as specified, replace the Heated Oxygen Sensor(s).