Test TC-65A: O2S 2/1 Stays At Center

NOTE: For connector terminal identification, see CONNECTOR IDENTIFICATION . For wiring diagram, see WIRING DIAGRAMS article.

For O2 sensor/model identification see O2 SENSOR 2/1 IDENTIFICATION table. Start engine. Allow engine to reach normal operating temperature. Using scan tool, set engine speed to 1500 RPM. Using scan tool, read O2S 2/1 state. If O2S 2/1 state is switching, go to next step. If O2S 2/1 state is not switching, go to step 6) .

O2 SENSOR 2/1 IDENTIFICATION

Application		Location
Avenger & Sebring Coupe
V6		Front Bank Upstream OS2

While monitoring scan tool display, wiggle O2S 2/1 wiring harness. If O2S 2/1 state locked at center, repair wiring harness as necessary where wiggling caused problem to appear. Perform TEST VER-5A . If O2S 2/1 state did not lock at center, go to next step.
Turn ignition off. Disconnect O2S 2/1 connector. Inspect wiring and connectors and repair as necessary. If no problems were found with wiring and connectors, go to next step. If wiring and connectors were repaired, perform TEST VER-5A .
Condition to set trouble code is not present at this time. O2S 2/1 STAYS AT CENTER DTC sets if O2S 2/1 signal voltage stays .35-.55 volts for 1.5 minutes. Possible causes are: O2S 2/1 output wire open, O2S 2/1 failure, PCM failure, dirt, moisture or grease causing voltage tracking in connector, or faulty connections or wiring. Go to next step.
Inspect all related wiring and connectors and repair as necessary. If no problems were found with wiring and connectors, see INACTIVE TROUBLE CODE CONDITION . Test is complete. Perform TEST VER-5A . If related wiring and connectors were repaired, perform TEST VER-5A .
Turn ignition off. Disconnect O2S 2/1 connector. Inspect wiring and connectors and repair as necessary. If no problems were found with wiring and connectors, go to next step. If wiring and connectors were repaired, perform TEST VER-5A .
Using an ohmmeter, check resistance of O2S 2/1 sensor ground circuit between O2S 2/1 connector (harness side) and ground. See O2S 2/1 CONNECTOR WIRE IDENTIFICATION (HARNESS SIDE) table. If resistance is 5 ohms or less, go to next step. If resistance is more than 5 ohms, repair open O2S 2/1 ground circuit. Perform TEST VER-5A .
Turn ignition on. Connect a jumper wire between O2S 2/1 connector (harness side) signal circuit and battery voltage. See O2S 2/1 CONNECTOR WIRE IDENTIFICATION (HARNESS SIDE) table. Using scan tool, read O2S 2/1 voltage. If voltage is one volt or less, go to next step. If voltage is more than one volt, replace O2S 2/1. Perform TEST VER-5A .
Turn ignition off. Disconnect Powertrain Control Module (PCM) connector. Inspect wiring and connectors and repair as necessary. If no problems were found with wiring and connectors, go to next step. If wiring and connectors were repaired, perform TEST VER-5A .
Disconnect jumper wire from O2S 2/1 connector. Using an ohmmeter, check resistance of O2S 2/1 sensor signal circuit between O2S 2/1 connector (harness side) and PCM terminal No. 29. See O2S 2/1 CONNECTOR WIRE IDENTIFICATION (HARNESS SIDE) table and PCM CONNECTOR WIRE IDENTIFICATION table. If resistance is less than 5 ohms, replace PCM. Perform TEST VER-5A . If resistance is 5 ohms or more, repair open O2S 2/1 signal ground circuit. Perform TEST VER-5A .

O2S 2/1 CONNECTOR WIRE IDENTIFICATION (HARNESS SIDE)

Application		Wire Color
O2S 2/1 Sensor Signal Circuit
Avenger & Sebring Coupe V6		Dark Green/Black
O2S 2/1 Sensor Ground Circuit
Avenger & Sebring Coupe V6		Black/Dark Green

PCM CONNECTOR WIRE IDENTIFICATION

Application		Wire Color
PCM Terminal No. 29 (O2S 2/1 Sensor Signal Circuit)
Avenger & Sebring Coupe		Dark Green/Black