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Oxygen Sensor 1 After Catalytic Converter - GX7-, Checking: Notes

General Description 

The Oxygen Sensor 1 After Catalytic Converter -GX7- is positioned downstream of the primary catalytic converter and it supplies the Engine/Motor Control Module -J623- with a voltage signal (nonlinear) indicating a "rich" or a "lean" condition is present. If the primary catalytic converter is supersaturated with oxygen (indicating a lean mixture is present), the Oxygen Sensor 1 After Catalytic Converter -GX7- will send the Engine/Motor Control Module -J623- a nonlinear signal indicating the lean mixture condition. The mixture is then enriched with fuel until the oxygen has been "displaced" from the catalytic converter. This new condition, in turn, is registered by the Oxygen Sensor 1 After Catalytic Converter -GX7- as a nonlinear signal indicating the rich mixture condition. The mixture is then leaned out by the Engine/Motor Control Module -J623-. If the nonlinear signal is received again, the mixture will again be enriched. The frequency, or period, during which the mixture is enriched or leaned out is variable, being dependent on the gas flow rate (engine load) at that moment.

Note The Oxygen Sensor 1 After Catalytic Converter -GX7- Is Also Known As The Oxygen Sensor After Three Way Catalytic Converter -G130-. 

The Oxygen Sensor 1 After Catalytic Converter -GX7- Contains The Following Components: 

The Oxygen Sensor 1 After Catalytic Converter -GX7- Components Cannot Be Serviced Separately, And They Must Be Serviced As A Unit. 

Special Tools And Workshop Equipment Required 

Test Requirements 

Test Procedure 

Step Procedure Result / Action to Take
  • PERFORM: Preliminary Check to verify the customers complaint. Refer to Oxygen Sensor Preliminary Tests in PRELIMINARY CHECK .
-- Was Complaint verified?
-- YES: -- NO:
  • GATHER more information from customer about the complaint.
  • IGNITION: OFF.
  • DISCONNECT: Oxygen Sensor 1 After Catalytic Converter -GX7- harness connector.
  • CHECK: Oxygen Sensor 1 After Catalytic Converter -GX7- component connector terminals 1 to 2 for resistance.
  • SPECIFIED VALUE: 2 - 4 Ω (+/- 0.5 Ω @ 25° C).
-- Was Value obtained?
-- YES: -- NO:
  • IGNITION: ON.
  • CHECK: Oxygen Sensor 1 After Catalytic Converter -GX7- harness connector terminal 1 to ground for voltage.
  • IGNITION: OFF.
  • SPECIFIED VALUE: Battery voltage.
-- Was Value obtained?
-- YES: -- NO:
  • RECONNECT: Oxygen Sensor 1 After Catalytic Converter -GX7- harness connector.
  • CONNECT: Scan Tool.
  • START: Engine and let Idle.
  • Perform the function test located in diagnostic mode 06. Refer to appropriate Diagnostic Mode 06 - Read Test Results for Specific Diagnostic Functions, DIAGNOSTIC MODES 01 - 0A .
  • IGNITION: OFF.
  • SPECIFIED VALUE: Mode 6 Pass.
-- Were Values obtained?
-- YES:
  • FAULT: Is intermittent.
  • PERFORM: Visual Inspection of wiring and component.
  • CHECK: Wiring for open, high resistance, short or harness connector for damage, corrosion, loose or broken terminals.
  • REPAIR: Faulty wiring or connector.
  • GO TO: Step 6 Oxygen Sensor 1 After Catalytic Converter - GX7-, CHECKING - 6 .
-- NO:
  • DISCONNECT: Oxygen Sensor 1 After Catalytic Converter -GX7- harness connector.
  • REMOVE: Engine/Motor Control Module -J623-. Refer to appropriate service information.
  • CHECK: Oxygen Sensor 1 After Catalytic Converter -GX7- harness connector terminal 2 to the Engine/Motor Control Module -J623- harness connector T94 / 7 for resistance.
  • CHECK: Oxygen Sensor 1 After Catalytic Converter -GX7- harness connector terminal 3 to the Engine/Motor Control Module -J623- harness connector T94 / 76 for resistance.
  • CHECK: Oxygen Sensor 1 After Catalytic Converter -GX7- harness connector terminal 4 to the Engine/Motor Control Module -J623- harness connector T94 / 77 for resistance.
  • SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω).
-- Were Values obtained?
-- YES: -- NO:
Refer to the Final Procedure Below