Heated Oxygen Sensor (Ho2S) No. 2
- Start engine and allow it to reach normal operating temperature. Pull back seal at HO2S No. 2 connector. Using a voltmeter, backprobe HO2S No. 2 connector between sensor signal and sensor ground terminal. See Fig 1 .
- Increase engine speed to 2000 RPM and hold for about one minute while observing voltmeter. Reading should be far less active than HO2S No. 1. If voltage is not as specified, see DTC P0136 and P0420 in appropriate BASIC TESTING article. Since many computer-controlled and monitored components set a Diagnostic Trouble Code (DTC) if they malfunction, also perform procedures in the appropriate TESTS W/CODES article. Heated Oxygen Sensor (HO2S) Heaters No. 1 & 2 - Turn ignition off. Disconnect HO2S No. 1 or 2 pigtail connector. Using an ohmmeter, measure resistance between VB and GND terminals. See Fig 1 . Refer to the HO2S HEATER RESISTANCE table. Replace HO2S if resistance is not as specified.
HO2S HEATER RESISTANCE @ 68°F (20°C)
| Application | Ohms |
|---|---|
| Swift | 11.7-15.6 |