Code P0141 - Secondary Ho2S Heater Malfunction
- Connect and operate scan tester, following manufacturer's instructions. Clear codes. Start and idle engine for 2 minutes. If Code P0141 appears, go to next step. If Code P0141 does not appear, problem is intermittent. Inspect for poor connections or loose wires associated with secondary HO2S and ECM, then repair as necessary.
- Turn ignition off. Unplug secondary HO2S connector. Measure resistance between Black wires at sensor. If resistance is 10-40 ohms, go to next step. If resistance is not 10-40 ohms, temporarily substitute known good sensor, then retest system.
- Test for continuity between ground and each Black wire at sensor. If continuity does not exist, go to next step. If continuity exists, replace sensor.
- Turn ignition on. Measure voltage between Black/Yellow and Green/Yellow wires at sensor harness connector. If battery voltage does not exist, go to next step. If battery voltage exists, go to step 7).
- Measure voltage between Black/Yellow wire at HO2S harness connector and ground. If battery voltage exists, go to next step. If battery voltage does not exist, repair open Black/Yellow wire between sensor and No. 4 ECU fuse.
- Turn ignition off. Reconnect wiring to HO2S. Turn ignition on. engine. Measure voltage between ECM terminals A17 (Green/Red wire) and A12 (Black wire). If voltage is not greater than 0.1 volt, repair open or shorted Green/Red wire between ECM and sensor. If voltage is as specified, temporarily substitute known good ECM, then retest system.
- Turn ignition off. Unplug 26-pin connector "A" from ECM. Test for continuity between harness connector pin A17 (Green/Red wire) and ground. If continuity exists, repair shorted Green/Red wire. If continuity does not exist, temporarily substitute known good ECM, then retest system.