Test TC-129A - O2 Sensor 1/2 Stays At Center
NOTE:
For connector terminal identification, see CONNECTOR IDENTIFICATION in SELF-DIAGNOSTICS section in this article. For wiring diagram, see WIRING DIAGRAMS - 3.2L
article.
- For O2 sensor/model identification see O2 SENSOR 1/2 IDENTIFICATION table. Turn ignition on with engine off. Using scan tool, monitor O2S 1/2 voltage. Wait for voltage reading to stabilize between .4-.6 volt. Using scan tool, actuate O2S 1/2 heater test. Monitor O2S 1/2 voltage for 2 minutes. If O2S 1/2 voltage is still .4-.6 volt, go to step 4). If O2S 1/2 voltage is not .4-.6 volt, go to next step.
- Using scan tool, stop actuation test. Turn ignition off. Disconnect O2S 1/2 connector. Inspect O2S 1/2 connector for damaged, pushed out or miswired terminals. Repair connector as necessary. Perform TEST VER-5A. If connector is okay, go to next step.
- Disconnect Powertrain Control Module (PCM) connector. Inspect PCM connector for damaged, pushed out or miswired terminals. Repair connector as necessary. Perform TEST VER-5A. If connector is okay, replace O2S 1/2. Perform TEST VER-5A.
- Using scan tool, stop actuation test. Turn ignition off. Disconnect O2S 1/2 connector. Inspect O2S 1/2 connector for damaged, pushed out or miswired terminals. Repair connector as necessary. Perform TEST VER-5A. If connector is okay, go to next step.
- Using an ohmmeter, check resistance of O2S ground circuit between O2S connector (harness side) and ground. See O2S 1/2 CONNECTOR WIRE IDENTIFICATION (HARNESS SIDE) table. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open sensor ground circuit. Perform TEST VER-5A.
- Disconnect Powertrain Control Module (PCM) connector. Inspect PCM connector for damaged, pushed out or miswired terminals. Repair connector as necessary. Perform TEST VER-5A. If connector is okay, go to next step.
- Using an ohmmeter, measure resistance of O2S 1/2 signal circuit between O2S 1/2 connector (harness side) and PCM connector terminal No. 51. See O2S 1/2 CONNECTOR WIRE IDENTIFICATION (HARNESS SIDE) table and PCM CONNECTOR WIRE IDENTIFICATION table. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open O2S signal circuit. Perform TEST VER-5A.
- Reconnect PCM connector. Turn ignition on. Connect a jumper wire between O2S signal circuit and sensor ground circuit terminals at O2S 1/2 connector (harness side). See O2S 1/2 CONNECTOR WIRE IDENTIFICATION (HARNESS SIDE) table. Using scan tool, read O2S 1/2 volts. If voltage less than 0.2 volt, replace O2S 1/2. Perform TEST VER-5A. If voltage is 0.2 volt or more, replace PCM. Perform TEST VER-5A.