Oxygen Sensor Relay: Testing and Inspection

Normally-open type A:




Check for continuity between the terminals.

- There should be continuity between the No.1 and No.2 terminals when power and ground are connected to the No.3 and No.4 terminals.
- There should be no continuity between the No.1 and No.2 terminals when power is disconnected.

Type 1:

Type 2:

Heated Oxygen Sensor Relay (California)