Test Dr-2A - Testing Oxygen (O2) Sensor
NOTE:
For connector terminal identification, see CONNECTOR IDENTIFICATION
. For appropriate wiring diagram, see WIRING DIAGRAMS
at end of article.
- Using DRB-II, erase fault codes. Start engine. Run engine until coolant temperature is greater than 160°F (71°C). Read O2 sensor voltage. If O2 sensor voltage is not a constant zero volts, go to step 3). If O2 sensor voltage is a constant zero volts, go to next step.
- Disconnect O2 sensor connector. If O2 sensor voltage is still a constant zero volts, repair White wire for short to ground between ECU 24-pin connector terminal No. 4 and O2 sensor connector. Perform TEST VER-2. If O2 sensor voltage is no longer a constant zero volts, replace O2 sensor. Perform TEST VER-2.
- Recheck O2 sensor voltage. If O2 sensor voltage is not a constant .03 volt, replace O2 sensor. Perform TEST VER-2. If O2 sensor voltage is a constant .03 volt, disconnect O2 sensor connector. Connect jumper wire between O2 sensor White wire and ground.
- If O2 sensor voltage is still a constant .03 volt, go to step 6). If O2 sensor voltage is no longer a constant .03 volt, turn ignition off. Measure resistance between O2 sensor Black wire and ground.
- If resistance is more than 10 ohms, repair open circuit in Black wire between ECU terminal No. 24 and O2 sensor. Perform TEST VER-2. If resistance is less than 10 ohms, replace O2 sensor. Perform TEST VER-2 .
- Turn ignition off. Disconnect ECU 24-pin connector. Measure resistance of White wire between ECU connector terminal No. 4 and O2 sensor connector. If resistance is more than 10 ohms, repair open circuit in White wire between ECU 24-pin connector terminal No. 4 and O2 sensor connector. Perform TEST VER-2. If resistance is less than 10 ohms, replace ECU. Perform TEST VER-2.