Turn the ignition switch OFF.
Disconnect the HO2S connector.
Measure resistance between the HO2S terminals 2 and 5 [B1/S1] [EURO 5 only].
Measure resistance between the HO2S terminals 3 and 4 [B1/S1] [Except EURO 5].
Measure resistance between the HO2S terminals 3 and 4 [B1/S2].
Check that the resistance is within the specification.
Specification: Refer to “Specification”