Many malfunctions in the electrical system are caused by poor harness and terminals.
Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Has a problem been found?
YES
▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure
NO
▶ Go to " Signal Circuit Inspection " procedure.
■ Check open in harness
IG "OFF" and disconnect HO2S(B1/S2) connector.
IG "ON" and ENG "OFF"
Measure voltage between signal termianl of HO2S(B1/S2) harness connector and chassis ground.
Specification : Approx. 3.5V - when pumping current is ON
Approx. 0.45V - when pumping current is OFF
Is the measured voltage within specification?
YES
▶ Go to "Ground Circuit Inspection" procedure.
NO
▶ Repair open in harness, and go to "Verification of Vehicle Repair" procedure.
■ Check open in harness
IG "ON" and disconnect HO2S(B1/S2) connector.
Measure voltage between signal terminal of HO2S(B1/S2) harness connector and chassis ground.(Measurement "A")
Measure voltage between signal and ground terminals of HO2S(B1/S2) harness connector.(Measurement "B")
Specification : Voltage difference between measurement "A" and "B" is below 200mV.
Is the measured voltage within specification?
YES
▶ Go to "Component inspection" procedure.
NO
▶ Repair open or contact resistance in harness, and go to "Verification of Vehicle Repair" prcedure.
