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Test TC-129A: O2 Sensor 1/2 Stays At Center

NOTE: For connector terminal identification, see CONNECTOR IDENTIFICATION . For wiring diagram, see WIRING DIAGRAMS article.
  1. 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.
    O2 SENSOR 1/2 IDENTIFICATION

    Application Location
    Avenger, Sebring Coupe & Talon
    4-Cylinder Downstream O2S
    V6 Rear Bank Downstream O2S
    Breeze, Cirrus, Neon, Sebring Conv. & Stratus
    4-Cylinder & V6 Downstream O2S
  2. 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.
  3. 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 .
  4. 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.
  5. 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 .
  6. 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.
  7. 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 .
  8. 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 .
O2S 1/2 CONNECTOR WIRE IDENTIFICATION (HARNESS SIDE)

Application Wire Color
O2S 1/2 Signal Circuit
Avenger, Sebring Coupe & Talon White/Dark Green
Breeze, Cirrus, Neon, Sebring Conv. & Stratus Tan/White
O2S 1/2 ASD Relay Output Circuit
Avenger, Sebring Coupe & Talon Black/Red
Breeze, Cirrus, Sebring Conv. & Stratus Orange/Dark Green
Neon Dark Green/Orange
O2S 1/2 Heater Ground Circuit
All Models Black
PCM CONNECTOR WIRE IDENTIFICATION

Application Wire Color
PCM Terminal No. 51 (O2S 1/2 Signal Circuit)
Avenger, Sebring Coupe & Talon White/Dark Green
Breeze, Cirrus, Neon, Sebring Conv. & Stratus Tan/White
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