Test TC-102A - O2 Sensor 1/1 Slow Response

NOTE: For connector terminal ID, see CONNECTOR IDENTIFICATION Directory. For wiring diagram, see WIRING DIAGRAMS - 2.0L article.

For O2 sensor/model identification see O2 SENSOR 1/1 IDENTIFICATION table. O2 SENSOR 1/1 SLOW RESPONSE DTC sets if upstream O2S 1/1 signal voltage is switching from less than .39 volt to more than .6 volt and back fewer times than required. Possible causes are: exhaust leak, fuel contamination, dirty or wet O2 sensor connector causing voltage tracking or engine mechanical failure. Go to next step.

O2 SENSOR 1/1 IDENTIFICATION

Application	Location
4-Cylinder	Upstream O2S
V6	Rear Bank Upstream O2S

Start engine. Check for exhaust system leaks between engine and catalytic converter. If no exhaust system leaks are found, go to next step. If exhaust system leaks are found, repair exhaust system as necessary. Perform TEST VER-5A.
Check exhaust for excessive smoke from oil consumption. If high oil consumption is not present, go to next step. If high oil consumption is present, repair engine mechanical failure as necessary. Replace O2S1/1. Perform TEST VER-5A.
Turn ignition off. Disconnect O2S 1/1 connector. Using an ohmmeter, check resistance of sensor ground circuit at O2S 1/1 connector (harness side). See O2S 1/1 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. If condition of PCM connector is okay, replace O2S1/1. Perform TEST VER-5A. If condition of PCM connector is not okay, repair as necessary. Perform TEST VER-5A.

O2S 1/1 CONNECTOR WIRE IDENTIFICATION (HARNESS SIDE)

Application	Wire Color
O2S 1/1 Sensor Signal Circuit	White/Black
O2S 1/1 Sensor Ground Circuit	Black/Dark Green