Turn the ignition switch OFF.
Disconnect the HO2S connector.
Measure resistance between the HO2S terminals 4 and 5 [B1/S1] [Euro-V].
Measure resistance between the HO2S terminals 3 and 4 [B1/S1] [Except Euro-V].
Measure resistance between the HO2S terminals 3 and 4 [B1/S2].
Check that the resistance is within the specification.
Specification: Refer to “Specification”