Purpose Of Readiness Tests

The On-Board Diagnostic (OBD II) system is designed to monitor the performance of emission-related components, and report any detected abnormalities with Diagnostic Trouble Codes (DTCs). Since various components need to be monitored during different driving conditions, the OBD II system is designed to run separate monitoring programs called readiness monitors.
The hand-held tester's software must be version 9.0 or newer to view the readiness monitor status. From the "Enhanced OBD II Menu", select "Monitor Status" to view the readiness monitor status.
A generic OBD II scan tool can also be used to view the readiness monitor status.
When the readiness monitor status reads "complete", the necessary conditions have been met for running performance tests for that readiness monitor.

HINT:

Many state Inspection and Maintenance (I/M) programs require a vehicle's readiness monitor status to show "complete" before beginning emissions test.

The Readiness Monitor will be reset to "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 "incomplete", follow the appropriate readiness monitor drive pattern to change the status to "complete".

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

NOTE: The following drive patterns are the fastest method of completing all the requirements necessary for making the readiness monitor status read "complete". If forced to momentarily stop a drive pattern due to traffic or other factors, the drive pattern can be resumed. Upon completion of the drive pattern, in most cases, the readiness monitor status will change to "complete". Sudden changes in vehicle load and speed, such as driving up and down hills and/or sudden acceleration, hinder completion of the readiness monitor.

Contents:

STEP DESCRIPTION

TITLE	STEP(s)
Catalyst Monitor	1
EVAP System Monitor	2
HO2S (heated oxygen sensor) Monitor	3
HO2S (heated oxygen sensor) Heater Monitor	4

CATALYST MONITOR

Fig 1: Catalyst Monitor Graph
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. Preconditions
  The monitor will not run unless:
  - The MIL is OFF.
  - ECT is 75°C (167°F) or greater.
  - IAT is -10°C (14°F) or greater.
  NOTE: The readiness test can be completed in cold ambient conditions (less than -10°C/14°F). Finish the drive pattern, turn the ignition switch OFF and then on again, and repeat the drive pattern a second time.
2. Drive Pattern
  1. Connect the hand-held tester to DLC3 to check readiness monitor status and preconditions (refer to step a).
  2. Drive vehicle at 64 to 88 km/h (40 to 55 mph) for approximately 3 minutes.
    NOTE: Drive with smooth throttle operation and avoid sudden acceleration.
    If IAT was less than 10°C (50°F) when the engine was started, drive the vehicle at 64 to 88 km/h (40 to 55 mph) for an additional 3 minutes.
  3. Drive the vehicle at 56 to 72 km/h (35 to 45 mph) for approximately 7 minutes.
    NOTE: Drive with smooth throttle operation and avoid sudden closure of the throttle.
  4. Check the status of the readiness monitor on the scan tool display. If readiness monitor status does not switch to complete, ensure that the preconditions are met, turn the ignition switch OFF, and then repeat steps ( 2) and ( 3).
EVAP SYSTEM MONITOR
NOTE: A cold soak must be performed prior to conducting the drive pattern to complete the Internal Pressure readiness monitor.
1. Cold Soak Preconditions
  The monitor will not run unless:
  - The MIL is OFF.
  - Fuel level is approximately 1/2 to 3/4 full.
  - Altitude is 2,400 m (7,874 feet) or less.
2. Cold Soak Procedure
  Let vehicle cold soak for 8 hours or until the difference between IAT and ECT is less than 7°C (13°F).
  
  Fig 2: EVAP System Monitor Graph
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Preconditions
  The monitor will not run unless:
  - The MIL is OFF.
  - Fuel level is approximately 1/2 to 3/4 full.
  - The altitude is 2,400 m (7,874 feet) or less.
  - ECT is between 4.4°C and 35°C (40°F and 95°F).
  - IAT is between 4.4°C and 35°C (40°F and 95°F).
  - The cold soak procedure has been completed.
  - Before starting the engine, the difference between ECT and IAT must be less than 7°C (13°F).
  HINT:
  - Example 1:
    ECT = 24°C (75°F)
    
    IAT = 16°C (60°F)
    
    Difference between ECT and IAT is 8°C (15°F).
    
    --> The monitor will not run because difference between ECT and IAT is greater than 7°C (13°F).
  - Example 2:
    ECT = 21°C (70°F)
    
    IAT = 20°C (68°F)
    
    Difference between ECT and IAT is 1°C (2°F).
    
    --> The monitor will run because "IAT - ECT" is between -7 and 11.1°C (-12.6 and 20°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 2,400 m (7,874 ft)). Finish the drive pattern, turn the ignition switch OFF and then on again, and repeat the drive pattern a second time.
4. Drive Pattern
  1. Connect the hand-held tester to the DLC3 to check monitor status and preconditions (refer to step a).
  2. Release pressure in fuel tank by removing the fuel tank cap and then reinstalling it.
  3. Start the engine and allow it to idle until ECT is 75°C (167°F) or more.
  4. Run the engine at 3,000 rpm for about 10 seconds.
  5. With the engine idling, turn the A/C ON to create a slight electrical load. Wait 15 to 50 minutes.
HEATED OXYGEN SENSOR MONITOR

Fig 3: Heated Oxygen Sensor 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 the hand-held tester to the DLC3 to check the monitor status and preconditions.
  2. Start the engine and allow it to idle for 2 minutes or more.
  3. Drive the vehicle at 40 km/h (25 mph) or more at least 50 seconds.
  4. Stop the vehicle and allow the engine to idle for 40 seconds or more.
  5. Perform steps ( 3) and ( 4) ten times.
  6. If readiness status does not switch to complete, ensure that the preconditions are met, turn the ignition switch OFF and then repeat steps ( 1) through ( 5).
HEATED OXYGEN SENSOR HEATER MONITOR

Fig 4: Heated 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 the hand-held tester to the DLC3 to check the monitor status and preconditions (refer to step a).
  2. Start the engine and allow it to idle for 8 minutes and 20 seconds or more.
  3. Drive the vehicle at 40 km/h (25 mph) or more for at least 2 minutes.
  4. Check the readiness monitor status. If the readiness monitor status does not change to "complete", double-check the preconditions, turn the ignition switch OFF, and repeat steps ( 2) to ( 3).