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 " Power Circuit Inspection " procedure.
IG "OFF" & Disconnect HO2S(B2/S2) connector.
IG "ON" & ENG "OFF".
Measure voltage between terminal 3 of HO2S(B2/S2) harness connector and chassis ground.
Specification : B+
Is the measured voltage within specification ?
YES
Go to "Control Circuit Inspection" procedure.
NO
Repair open or short to ground in HO2S(B2/S2) Heater power circuit then, go to "Verification of Vehicle Repair" procedure.
Check short to ground in harness
IG "OFF" and disconnect HO2S(B2/S2) connector.
Measure resistance between terminal 4 of HO2S(B2/S2) harness connector and chassis ground.
Specification : Infinite
Is the measured resistance within specification ?
YES
Go to "Check Open in harness" as follows.
NO
Repair short to ground in HO2S (B2/S2) heater control circuit and go to "Verification of Vehicle Repair" procedure.
Check open in harness
IG "OFF" and disconnect HO2S(B2/S2) and PCM connector.
Measure resistance between terminal 4 of HO2S(B2/S2) harness connector and terminal 73 of PCM harness connector.
Specification : Approx. below 1Ω
Is the measured resistance within specification ?
YES
Go to "Component Inspection" procedure.
NO
Repair open in HO2S(B2/S2) heater control circuit and go to "Verifiction of Vehicle Repair" procedure.