Air Fuel Ratio Af And Heated Oxygen Sensor Ho Monitor Active Air Fuel Ratio Control Type

a. Preconditions

The monitor will not run unless:

■ 2 minutes or more have elapsed since the engine was started.

■ The Engine Coolant Temperature (ECT) is 75°C (167°F) or higher.

■ Air fuel ratio feedback control is performed.

■ Fuel-cut control is performed for 8 seconds or more (for the Rear HO2 Sensor Monitor).

b. Drive Pattern for front A/F sensor and rear HO2 sensor

1. Connect the intelligent tester to the DLC3.

2. Turn the ignition switch ON.

3. Turn the tester ON.

5. Start the engine, and warm it up until the ECT reaches 75°C (167°F) or higher.

6. Drive the vehicle at 38 mph (60 km/h) or more for at least 10 minutes.

7. Change the transmission to 2nd gear.

8. Accelerate the vehicle to 40 mph (64 km/h) or more by depressing the accelerator pedal for at

2007 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Sequoia least 10 seconds.

9. Soon after performing the step above, release the accelerator pedal for at least 4 seconds without depressing the brake pedal, in order to execute fuel-cut control.

10. Allow the vehicle to decelerate until the vehicle speed declines to less than 6 mph (10 km/h).

11. Repeat steps from (8) through (10) above at least 3 times in one driving cycle. c. Monitor Status

1. Check the Readiness Monitor status displayed on the tester.

2. If the status does not switch to COM PL (complete), make sure that the preconditions have been met, and then perform steps from (5) through (11) in "Drive Pattern" procedures above.

Fig. 12: Vehicle Speed And Accelerator Pedal Monitor Drive Pattern
Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

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