Purpose Of The Readiness Tests

The On-Board Diagnostic (OBD II) system is designed to monitor the performance of emission related components, and indicate any detected abnormalities with DTCs (Diagnostic Trouble Codes). Since various components need to be monitored during different driving conditions, the OBD II system is designed to run separate monitoring program called Readiness Monitors.
The hand-held tester's software must be version 9.0 or newer to view the Readiness Monitor status. To view the status, select the following menu items: DIAGNOSIS /ENHANCED OBD II / MONITOR STATUS.
A generic OBD II scan tool can also be used to view the Readiness Monitor status.
When the Readiness Monitor status reads COMPL (complete), the necessary conditions have been met for running the perform tests for that Readiness Monitor.
NOTE: Many state Inspection and Maintenance (I/M) programs require a vehicle's Readiness Monitor status to show COMPL before beginning emission tests.
The Readiness Monitor will be reset to INCMPL (incomplete) if:
- The ECM has lost battery power or blown a fuse.
- DTCs have been cleared.
- The conditions for running the Readiness Monitor have not been met.
If the Readiness Monitor status shows INCMPL, follow the appropriate Readiness Monitor Drive Pattern to change the status to COMPL.

CAUTION: Strictly observe posted speed limits, traffic laws, and road conditions when performing these drive patterns.

NOTE: These drive patterns represent the fastest method of satisfying all the conditions necessary to achieve complete status for each specific Readiness Monitor.
In the event of a drive pattern being interrupted (possibly due to factors such as traffic conditions), the drive pattern can be resumed. In most cases, the Readiness Monitor will still achieve complete status upon completion of the drive pattern.
To ensure completion of the Readiness Monitors, avoid sudden changes in vehicle load and speed (driving up and down hills and/or sudden acceleration).

CATALYST MONITOR (HEATED OXYGEN SENSOR TYPE)

Fig 1: Catalyst Monitor Graph (Heated Oxygen Sensor Type)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. Preconditions
  The monitor will not run unless
  - The MIL is OFF.
  - Engine Coolant Temperature (ECT) is 75°C (167°F) or higher.
  - Intake Air Temperature (IAT) is - 10°C (14°F) or higher.
  NOTE: The readiness test can be completed in cold ambient conditions (less than-10°C [14°F]), if the drive pattern is repeated a second time after switching the ignition off.
2. Drive Pattern
  1. Connect a hand-held tester or OBD II scan tool to the DLC3.
  2. Turn the ignition switch to ON
  3. Turn the tester or scan tool on.
  4. Clear DTCs (where set).
  5. Start the engine, and warm it up until the ECT reaches 75°C (167°F) or higher.
  6. Drive the vehicle at between 64 km/h and 88 km/h (40 mph and 55 mph) for approximately 3 minutes.
    NOTE: Drive with smooth throttle operation and avoid sudden acceleration.
    If the IAT was less than 10°C (50°F) when starting the engine, drive the vehicle at between 64 km/h and 88 km/h (40 mph and 55 mph) for approximately 3 additional minutes.
  7. Drive the vehicle at between 56 km/h and 72 km/h (35 mph and 45 mph) for approximately 7 minutes.
  NOTE: Drive with smooth throttle operation and avoid sudden deceleration that causes the throttle to close fully.
3. Monitor Status
  1. Check the Readiness Monitor status displayed on the tester or scan tool.
  2. If the status does not switch to COMP (complete), make sure that the preconditions have been met, and turn the ignition switch to OFF. Then, repeat steps (6) and (7) in Drive Pattern above.
EVAP MONITOR (VACUUM PRESSURE MONITOR)
NOTE: A cold soak must be performed prior to conducting the drive pattern in order to complete the EVAP System Monitor.
1. Cold Soak Preconditions
  - The MIL is OFF.
  - Fuel tank is approximately 1/2 to 3/4 full.
  - Altitude is 8,000 ft (2,400 m) or less.
  Fig 2: EVAP Monitor Graph (Vacuum Pressure Monitor)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Cold Soak
  Let the vehicle cold soak for 8 hours or until the difference between the Intake Air Temperature (IAT) and the Engine Coolant Temperature (ECT) reaches less than 7°C (13°F).
3. EVAP System Monitor Preconditions
  The monitor will not run unless:
  - The MIL is OFF.
  - Fuel tank is approximately 1/2 to 3/4 full.
  - Altitude is 8,000 ft (2,400 m) or less.
  - Cold soak has been completed.
  - The ECT is between 4.4°C and 35°C (40°F and 95°F)
  - The IAT is between 4.4°C and 35°C (40°F and 95°F)
  - The difference between the ECT and IAT at engine start is between -7°C and 11°C (19°F and 52°F) (the difference is calculated by deducting the ECT from the IAT).
  NOTE:
  - Example 1
    The ECT is 24°C (75°F) and the IAT is 16°C (60°F) when starting the engine.
    
    16°C (60°F) -24°C (75°F) = -8°C (-15°F)
    
    The monitor will not run because the difference between the temperatures is outside the precondition range of -7°C and 11°C (19°F and 52°F).
  - Example 2
    The ECT is 21°C (70°F) and the IAT is 20°C (68°F) when starting the engine.
    
    20°C (68°F) -21°C (70°F) = -1°C (-2°F)
    
    The monitor will run because the difference between the temperatures is within the precondition range of -7°C and 11°C (19°F and 52°F).
  NOTE: The readiness test can be completed in cold ambient conditions (less than 4.4°C [40°F]) and/or high altitudes (more than 8,000 ft [2,400 m]), if the drive pattern is repeated a second time after switching the ignition off.
4. Drive Pattern
  1. Release the pressure from the fuel tank by removing and reinstalling the fuel tank cap.
  2. Connect a hand-held tester or OBD II scan tool to the DLC3.
  3. Turn the ignition switch to ON.
  4. Turn the tester or scan tool ON.
  5. Clear DTCs (where set).
  6. Start the engine and warm it up until the ECT reaches 75°C (167°F) or higher.
  7. Run the engine at 3,000 RPM for approximately 10 seconds.
  8. Allow the engine to idle for 15 to 50 minutes with A/C ON (to create a slight engine load).
  NOTE: If the vehicle is equipped with A/C, follow the operation below in order to put a slight load on the engine.
  - Securely apply the parking brake.
  - Use wheel chocks to secure the wheels.
  - Move the gear selector lever to the D position, and allow the engine to idle for 15 to 50 minutes.
  CAUTION: Exercise extreme care and take preconditions during the operation. Failure to do so may result in the vehicle unexpectedly rolling away.
5. Monitor Status
  1. Check for Readiness Monitor status displayed on the tester or scan tool.
  2. If the status does not switch to COMPL (complete), make sure that the preconditions have been met, and then drive the vehicle at between 70- km/h and 120kn/h (43 mph and 74 mph) for approximately 50 minutes (keep the vehicle speed as constant as possible).
HEATED OXYGEN SENSOR MONITOR (FOR FRONT AND REAR HO2 SENSORS)
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.
  - Fuel-cut control is performed for 8 seconds or more (for the Rear HO2 Sensor Monitor)
2. Drive Pattern for Front and Rear HO2 Sensors
  1. Connect a hand-held tester or OBD II scan tool to the DLC3.
  2. Turn the ignition switch to ON.
  3. Turn the tester or scan tool on.
  4. Clear DTCs (where set).
  5. Start the engine, and warm it up until the ECT reaches 75°C (167°F) or higher.
  6. Drive the vehicle at 48 km/h (30 mph) or more for at least 40 seconds.
  7. Allow the engine to idle for 20 seconds or more.
  8. Repeat steps (6) and (7) at least 8 times in one driving cycle.
  9. Change the transmission to 2nd gear.
  10. Accelerate the vehicle to 48 km/h (30 mph) or more by depressing the accelerator pedal for at least 10 seconds.
  11. Soon after performing step (10) above, release the accelerator pedal for at least 10 seconds without depressing the brake pedal, in order to execute fuel-cut control.
  12. Allow the vehicle to decelerate until the vehicle speed declines to less than 10 km/h (6 mph).
  13. Repeat steps from (10) through (12) above at least twice in one driving cycle.
3. Monitor Status
  1. Check the Readiness Monitor status displayed on the tester or scan tool.
  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 (13) in Drive Pattern above.
Fig 3: HO2S Monitor Drive Pattern
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
OXYGEN SENSOR HEATER MONITOR

Fig 4: Oxygen Sensor Heater Monitor Graph
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. Preconditions
  The monitor will not run unless:
  - The MIL is OFF
2. Drive Pattern
  1. Connect a hand-held tester or OBD II scan tool to the DLC3.
  2. Turn the ignition switch to ON.
  3. Turn the tester or scan tool ON.
  4. Clear DTCs (where set).
  5. Start the engine and allow it to idle for 10 minutes or more.
  6. Drive the vehicle at 64 km/h (25 mph) or more for at least 2 minutes.
3. Monitor Status
  1. Check the Readiness Monitor status displayed on the tester or scan tool.