With Scan Tool

Using The Engine Signal Monitor
1. Remove the Powertrain Control Module (PCM).

SSTs Engine Signal Monitor:

2. Connect the Special Service Tool (SST) to the PCM.
3. Warm up the engine to normal operating temperature.
4. Measure the voltage at PCM terminals 3D, 3H, 3I and 3M.

Heated Oxygen Sensor Voltage Specifications:

5. If not as specified, inspect the following.
- Intake-air system
- Fuel system
- On-board diagnostic system
If these systems are OK, replace the heated oxygen sensor.

Tightening torque: 30-49 Nm (22-36 ft.lbs.)

New Generation Star (NGS) Tester, Connected to DLC-2:

Using The NGS
1. Connect the SSTs to the data link connector 2.

NGS Display:

2. Select the PID/DATA MONITOR AND RECORD function of New Generation Star (NGS) tester.
3. Select "FHO2S R", "RHO2S R", "FHO2S L" and "RHO2S L" on the NGS display. NGS measures and shows the voltage.

Heated Oxygen Sensor Voltage Specifications:

4. If not as specified, inspect the following.
- Intake-air system
- Fuel system
- On-board diagnostic system
If these systems are OK, replace the heated oxygen sensor.

Tightening torque: 30-49 Nm (22-36 ft.lbs.)

Heater
1. Disconnect the heated oxygen sensor connector.

Heated Oxygen Sensor #1 (H2OS-1) Connector:

Heated Oxygen Sensor #2 (H2OS-2) Connector:

Heated Oxygen Sensor #3 (H2OS-3) Connector:

2. Measure the resistance between heated oxygen sensor (front) terminals B and C by using an ohmmeter. Measure the resistance between heated oxygen sensor (middle, rear) terminals C and D by using an ohmmeter.

Specification: Approx. 6 Ohms 20°C (68°F)

3. If not as specified, replace the heated oxygen sensor.

Tightening torque: 30-49 Nm (22-36 ft.lbs.)