Many malfunctions in the electrical system are caused by poor harness(s) and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Check the following conditions:
Check for damaged harness and terminals: contact resistance, oxidation, bent or broken terminals.
Check for poor connection between ECM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection
Use a suitable male pin to ensure that contact in sockets is good. The pin should remain in position when pulled gently.
Has a problem been found?
YES
Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO
Go to "HO2S Signal Circuit Inspection" procedure.
IG KEY : OFF , Engine : OFF
Connect HO2S connector(C40) and ECM connector.
Measure resistance between terminal 1 of the HO2S harness connectorC40 and 1 of the ECM harness connector.C21-3
Specification : Approx. 0Ω.
Is the resistance near the specified value?
YES
Go to "Heater Circuit Inspection" procedure.
NO
Repair as necessary and go to "Verification Heater Circuit Inspection
IG KEY : ON , Engine : OFF
Disconnect HO2S connector(C40).
Measure voltage between terminal 3 of the HO2S harness connectorC40 and chassis ground.
Specification : Approx. B+
Is the voltage near the specified value?
YES
Go to "Check for Open in Harness" procedure.
NO
Possibility of open or short to ground
Repair as necerssary and go to "Verification of Vehicle Repair" procedure.
IG KEY : OFF , Engine : OFF
Disconnect HO2S connector(C40) and ECM connector.
Measure resistance between terminal 4 of the HO2S harness connectorC40 and 3 of the ECM harness connector.C21-1
Specification : Approx. 0Ω.
Is the resistance near the specified value?
YES
Go to "System Inspection" procedure.
NO
Repair as necessary and go to "Verification of Vehicle Repair" procedure.
