Toyota RAV4 Service Manual: Air-fuel ratio (a/f) and heated oxygen (ho2) sensor monitors (active air-fuel ratio control type)

1. 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 more.
• Cumulative driving time at a vehicle speed of 48 km/h (30 mph) or more exceeds 6 minutes.
• Air-fuel ratio feedback control is performed.

2. Drive pattern for front a/f sensor and ho2 sensor

1. Connect the intelligent tester to the dlc3.
2. Turn the ignition switch on.
3. Turn the tester on.
4. Clear dtcs (see page es-35).
5. Start the engine, and warm it up until the ect reaches 75°c (167°f) or higher.
6. Drive the vehicle at between 60 km/h (38 mph) and 120 km/h (75 mph) for at least 10 minutes.
7. Change the transmission to 2nd gear.
8. Accelerate the vehicle to 64 km/h (40 mph) or more by depressing the accelerator pedal for at least 10 seconds.
9. Soon after performing step (8) above, release the accelerator pedal for at least 4 seconds without depressing the brake pedal, in order to execute fuelcut control.
10. Allow the vehicle to decelerate until the vehicle speed declines to less than 10 km/h (6 mph).
11. Repeat steps from (8) through (10) above at least 3 times in one driving cycle.

3. Monitor status

1. Check the readiness monitor status displayed on the tester.
2. If the status does not switch to compl (complete), make sure that the preconditions have been met, and then perform steps from (5) through (11) in the drive pattern above.