Heated Oxygen Sensor -G39-, CHECKING

Function 

The Heated Oxygen Sensor -G39- does not actually measure oxygen concentration, but rather the difference between the amount of oxygen in the exhaust gas and the amount of oxygen in air. Rich mixture causes an oxygen demand. This demand causes a voltage to build up, due to transportation of oxygen ions through the Heated Oxygen Sensor -G39- layer. Lean mixture causes low voltage, since there is an oxygen excess. The Engine Heated Oxygen Sensor -G39- and catalytic converters are used in order to reduce exhaust emissions. Information on oxygen concentration is sent to Engine Control Module -J623-, which adjusts the amount of fuel injected into the engine to compensate for excess air or excess fuel. The Engine Control Module -J623- attempts to maintain, on average, a certain air-fuel ratio by interpreting the information it gains from the Heated Oxygen Sensor -G39-. The primary goal is a compromise between power, fuel economy, and emissions. The Heater for Heated Oxygen Sensor -G39- is designed to minimize the time-to-readiness for closed-loop operation by heating the Heated Oxygen Sensor -G39- as quickly as possible.

The Heated Oxygen Sensor -G39- contains the following components:

• Oxygen Sensor Heater -Z19-

The Heated Oxygen Sensor -G39- components cannot be serviced separately, it must be serviced as a unit.

Special tools and workshop equipment required 

• Multimeter
• Wiring Diagram
• Scan Tool

Test requirements 

• Fuses OK.
• Battery voltage OK.
• Switch OFF all electrical and electronic accessories.
• Vehicles with Auto. Transmission, ensure Selector Lever position is in "P".
• Vehicles with Man. Transmission, ensure Shifter Lever position is in "N" with Parking Brake applied.
• Coolant Temperature: ≥ 80° C.
• Observe all safety precautions. Refer to: SAFETY PRECAUTIONS .
• View clean working conditions. Refer to: CLEAN WORKING CONDITIONS .

Test Procedure