Control Circuit Inspection

Measure voltage between control terminal 3 of HO2S (B1/S1) heater harness connector and chassis ground.
Specification: Approx. 4 ~ 5 V
Is voltage within the specification?
YES
- Go to "COMPONENT INSPECTION " procedure.
NO
- Repair as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure
  NOTE: HO2S must have a clean air reference to function properly. The air is obtained by way of the sensor wire(s). Do not attempt to repair the wire(s), connector, or the terminals.