Test TC-181A - O2S 2/1 Shorted To Ground
NOTE:
For connector terminal identification, see CONNECTOR IDENTIFICATION in SELF-DIAGNOSTICS section in this article. For wiring diagram, see WIRING DIAGRAMS - 2.7L
article.
- For O2 sensor/model identification see O2 SENSOR 2/1 IDENTIFICATION table. O2S 2/1 VOLTAGE SHORTED TO GROUND DTC sets if O2S 2/1 signal voltage is less than .156 volt for 28 seconds after engine start. Possible causes are: O2S 2/1 output wire shorted to ground, dirty or wet O2S 2/1 connector causing voltage tracking, O2S2/1 failure, Powertrain Control Module (PCM) failure or faulty connections or wiring. Go to next step.
- Start engine. Using scan tool, observe O2S 2/1 voltage for a few minutes. If O2S 2/1 voltage is less than .16 volt, go to next step. If O2S2/1 voltage is .16 volt or more, condition to set trouble code is not present at this time. Perform TEST VER-5A.
- Turn ignition off. Disconnect O2S 2/1 connector. Turn ignition on. Using scan tool, read O2S 2/1 voltage. If voltage is less than .16 volt, go to next step. If voltage is .16 volt or more, replace O2S 2/1. Perform TEST VER-5A.
- Turn ignition off. Disconnect PCM connector. Using an ohmmeter, check resistance between O2S 2/1 signal circuit and O2S 2/1 ground circuit at O2S 2/1 connector (harness side). See O2S 2/1 CONNECTOR WIRE IDENTIFICATION (HARNESS SIDE) table. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground circuit on O2S 2/1 signal circuit. Perform TEST VER-5A.
- Using an ohmmeter, check resistance between O2S 2/1 signal circuit and chassis ground at O2S 2/1 connector (harness side). See O2S 2/1 CONNECTOR WIRE IDENTIFICATION (HARNESS SIDE) table. If resistance is 5 ohms or more, replace PCM. Perform TEST VER-5A. If resistance is less than 5 ohms, repair short to ground on O2S 2/1 signal circuit. Perform TEST VER-5A.