DTC P0141 - Ho2S No. 2 Heater Circuit Malfunction

NOTE: Before replacing HO2S No. 2, inspect sensor for contamination. If contamination is present, determine cause and repair before installing a new HO2S No. 2.

Turn ignition off. Disconnect HO2S No. 2 harness connector. Using an ohmmeter, measure resistance between terminals No. 3 and 4 of HO2S No. 2. See Figure . If resistance is 2.0-100 ohms, go to next step. If resistance is not as specified, replace HO2S No. 2. Retest system.
Reconnect HO2S No. 2 harness connector. Turn ignition on. Using a voltmeter, measure voltage (backprobe) between ground and PCM harness connector "C", terminal No. 13 (Pink/White wire). If reading is 10-14 volts, go to next step. If reading is not as specified, check Black/White wire between relay/fuse box and HO2S No. 2 for an open or short to ground. Check Pink/White wire between PCM and HO2S No. 2 for an open or short to ground. Check for poor connection at HO2S No. 2. Repair as necessary. If wires and connections are okay, replace PCM. Retest system.
Start engine and allow it to reach normal operating temperature. Using a voltmeter, measure voltage (backprobe) between ground and PCM harness connector "C", terminal No. 13 (Pink/White wire) with engine idling. If reading is 0-1 volt, check for an intermittent problem. See TESTS W/O CODES article. If reading is not as specified, check PCM harness connectors for poor connections. If connections are okay, replace PCM. Retest system.