To check the heated circuit of the O 2 S sensor:
- With the ignition OFF, check the resistance between terminal Nos. 1 and 2 of the O 2 S sensor connector. At room temperature the resistance should be 0.0-24.2 ohms.
- With the ignition OFF and the O 2 S sensor disconnected, use a suitable DMM to check the voltage between terminal Nos. 1 (+) and 2 (-). Start the engine and allow the engine to idle. The reading should be about 12-14 volts. If the voltage is not present, check the fuses and electrical wiring.