Readiness Monitor Drive Pattern
READINESS MONITOR DRIVE PATTERN1. PURPOSE OF THE READINESS TESTS
- The On Board Diagnostic (OBD II) system is designed to monitor the performance of emission related components and report any detected abnormalities in the form of Diagnostic Trouble Codes (DTCs). Since the various components need to be monitored during different driving conditions, the OBD II system is designed to run separate monitoring programs called Readiness Monitors. Many state Inspection and Maintenance (I/M) programs require that vehicles complete their Readiness Monitors prior to beginning an emissions test.
- The current status of the Readiness Monitors can be seen by using the hand-held tester with version 9.0 software (or newer), or a generic OBD II scan tool.
- To view the Readiness Monitor status using the hand-held tester, select "Monitor Status" from the Enhanced OBD II Menu.
- A status of "complete" indicates that the necessary conditions have been met to run the performance tests for the related Readiness Monitor.
- The Readiness Monitor will be reset to "incomplete" if:
- ECM has lost power (battery or fuse).
- DTCs have been cleared.
- The conditions for running the Readiness Monitor have not been met.
- In the event that any Readiness Monitor shows "incomplete", follow the appropriate Readiness Monitor Drive Pattern to change the readiness status to "complete".
CAUTION: Strict observance of posted speed limits, traffic laws, and road conditions are required when performing these drive patterns.
NOTE: These drive patterns represent the fastest method to satisfy all necessary conditions which allow the specific readiness monitor to complete.
In the event that the drive pattern must be interrupted (possibly due to traffic conditions or other factors) the drive pattern can be resumed, and in most cases, the readiness monitor will still set to complete.
To ensure rapid completion of readiness monitors, avoid sudden changes in vehicle load and speed (driving up and down hills and/or sudden acceleration).
2. CATALYST MONITOR (O2S TYPE)
a. Preconditions
The monitor will not run unless:
- MIL is OFF.
- Engine Coolant Temperature (ECT) is 176 °F (80 °C) or greater.
- Intake Air Temperature (IAT) is 14 °F (-10 °C) or greater.*
NOTE:
* 2002 and later MY vehicles:
The readiness test can be completed in cold ambient conditions (less than 14 °F/-10 °C), if the drive pattern is repeated a second time after cycling the ignition off.
b. Drive Pattern
1. Connect the OBD II scan tool to the DLC3 to check monitor status and preconditions.
2. Drive the vehicle at 40 to 55 mph (64 to 88 km/h) for approximately 3 minutes.
NOTE: Drive with smooth throttle operation and avoid sudden acceleration.
If IAT is less than 50 °F (10 °C) when starting engine, continue to drive vehicle at 40 to 55 mph (64 to 88km/h) for approximately 4 minutes.
3. Drive the vehicle at 35 to 45 mph (56 to 72 km/h) for approximately 7 minutes.
NOTE: Drive with smooth throttle operation and avoid sudden deceleration as much as possible with the throttle fully closed.
4. If readiness status does not switch to complete, make sure that the preconditions are met and the ignition switch is turned OFF and then repeat steps (2) and (3).
5. Release pressure in the fuel tank by removing the fuel tank cap, and then reinstall the cap.
6. Start the engine and immediately begin driving as directed.
3. EVAP MONITOR (VACUUM PRESSURE MONITOR)
NOTE: A cold soak must be performed prior to conducting the drive pattern to complete the Internal Pressure Readiness Monitor.
a. Cold Soak Preconditions
The monitor will not run unless:
- MIL is OFF.
- Fuel level is approximately 1/2 to 3/4.
- Altitude is 7800 feet (2400 m) or less.
b. Cold Soak Procedure Let the vehicle cold soak for 8 hours or until the difference between the intake air temperature (IAT) and engine coolant temperature (ECT) becomes less than 13 °F (7 °C).
HINT:
Examples:
- Scenario 1
ECT = 75 °F (24 °C)
IAT = 60 °F (16 °C)
Difference between ECT and IAT is 15 °F (8 °C).
->The monitor will not run because the difference between the ECT and IAT is greater than 13 °F (7 °C).
- Scenario 2
ECT = 70 °F (21 °C)
IAT = 68 °F (20 °C)
Difference between ECT and IAT is 2 °F (1 °C).
->The monitor will run because the difference between the ECT and IAT is less than 13 °F (7 °C).
4. EVAP MONITOR (VACUUM PRESSURE MONITOR) (CONTINUED)
a. Preconditions
The monitor will not run unless:
- MIL is OFF.
- Fuel level is approximately 1/2 to 3/4.
- Altitude is 7800 feet (2400 m) or less.*
- Engine Coolant Temperature (ECT) is between 40 °F and 95 °F (4.4 °C and 35 °C).
- Intake Air Temperature (IAT) is between 40 °F and 95 °F (4.4 °C and 35 °C).*
- Cold Soak Procedure has been completed.
- Before starting the engine, the difference between the ECT and IAT must be less than 13 °F (7 °C).
HINT:
Examples:
- Scenario 1
ECT = 75 °F (24 °C)
IAT = 60 °F (16 °C)
Difference between ECT and IAT is 15 °F (8 °C).
->The monitor will not run because the difference between the ECT and IAT is greater than 13 °F (7 °C).
- Scenario 2
ECT = 70 °F (21 °C)
IAT = 68 °F (20 °C)
Difference between ECT and IAT is 2 °F (1 °C).
->The monitor will run because the difference between the ECT and IAT is less than 13 °F (7 °C).
NOTE:
* NOTE for 2002 and later MY vehicles:
The readiness test can be completed in cold ambient conditions (less than 40 °F/4.4 °C) and/or at high altitudes (more than 7800 feet/2400 m) if the drive pattern is repeated a second time after cycling the ignition off.
b. Drive Pattern (Case 1: Vehicle equipped with A/C)
1. Connect the OBD II scan tool to the DLC3 to check the monitor status and preconditions.
2. Release the pressure from the fuel tank by removing the fuel tank cap. Reinstall the cap.
3. Start the engine and allow it to idle until the engine coolant temperature (ECT) becomes 75 °C (167 °F) or higher.
4. Run the engine at 3,000 rpm for about 10 seconds.
5. Allow the engine to idle with the A/C ON for 15 to 50 minutes (to create a slight engine load).
c. Drive Pattern (Case 2: AT vehicle not equipped with A/C)
1. Perform the same operation, from (1) to (4), described in (b).
2. Securely apply the parking brake.
3. Shift the shift lever into the Drive position, and leave the engine running for 15 to 50 minutes.
CAUTION: Exercise extreme care and take precautions in this operation. Failure to perform them, unexpected vehicle roll-away may result.
d. Drive Pattern (Case 2: MT vehicle not equipped with A/C)
1. Perform the same operation, from (1) to (4), described in (b).
2. Turn the high beam lights and rear defogger ON.
3. Allow the engine to idle for 15 to 50 minutes.
5. OXYGEN SENSOR MONITOR (FRONT AND REAR O2S SYSTEM)
a. Preconditions
The monitor will not run unless:
- MIL is OFF
b. Drive Pattern
1. Connect the OBD II scan tool to the DLC3 to check monitor status and preconditions.
2. Start the engine and allow it to idle for 2 minutes or more.
3. Drive the vehicle at 25 mph (40 km/h) 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 the readiness status dose not switch to complete, make sure that the preconditions are met and the ignition switch is turned OFF and then repeat steps (1) through (5).
6. OXYGEN/AF SENSOR HEATER MONITOR
a. Preconditions
The monitor will not run unless:
- MIL is OFF
b. Drive Pattern
1. Connect the OBD II scan tool to the DLC3 to check monitor status and preconditions.
2. Start the engine and allow it to idle for 9 minutes.
3. Drive the vehicle at 25 mph (40 km/h) or more at least 2 minutes.
4. If the readiness status dose not switch to complete, make sure that the preconditions are met and the ignition switch turned OFF and then repeat steps (2) and (3).