Control Circuit Inspection

Check Short in control circuit
1. IG "OFF" & Disconnect HO2S (S2)_DOWN connector.
2. IG "ON".
3. Measure the voltage between heater control terminal "4" of HO2S (S2)_DOWN harness connector and chassis ground.
  Specification : Approx. 3.5V
4. Is the measured voltage within specification?
  YES
  - Go to "COMPONENT INSPECTION " procedure.
  NO
  - Repair Short to ground in control circuit and then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.