Readiness Monitor Drive Pattern

READINESS MONITOR DRIVE PATTERN

1. 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 active the monitor and change the readiness status to "complete".

CAUTION: Strictly observe of posted speed limits, traffic laws, and road conditions 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 (A/F SENSOR TYPE)

a. Preconditions
The monitor will not run unless:
- MIL is OFF.
- Engine Coolant Temperature (ECT) is 80 °C (176 °F) or greater.
- Intake Air Temperature (IAT) is -10 °C (14 °F) or greater *.

NOTE:
* 2002 and later MY vehicles:
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 cycling the ignition off.

b. Drive Pattern
1. Connect the OBD II scan tool to DLC3 to check monitor status and preconditions (refer to step "a").
2. Drive vehicle at 40 to 55 mph (64 to 88 km/h) for approximately 4 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 40 to 55 mph (64 to 88 km/h) for additional 4 minutes.

3. Drive vehicle allowing speed to fluctuate between 40 to 50 mph (64 to 80 km/h) for about 16 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 status did not switch to complete, ensure preconditions are met, turn ignition off, and then repeat steps (2) and (3).

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 full.
- Altitude is 7,800 feet (2,400 m) or less.

b. 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).

HINT:
Examples:
- Scenario 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).

- Scenario 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 difference between ECT and IAT is less than 7 °C (13 °F).

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 full.
- Altitude is 7800 feet (2400 m) or less.*
- Engine Coolant Temperature (ECT) is between 4.4 °C and 35 °C (40 °F and 95 °F).
- Intake Air Temperature (IAT) is between 4.4 °C and 35 °C (40 °F and 95 °F).*
- 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:
Examples:
- Scenario 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).

- Scenario 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 difference between ECT and IAT is less than 7 °C (13 °F).

NOTE:
* NOTE for 2002 and later MY vehicles:
The readiness test can be completed in cold ambient conditions (less than 4.4 °C/40 °F) and/or at high altitudes (more than 7,800 feet/2,400 m) 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 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 to idle until ECT is 75 °C (167 °F) or more.
4. Run the engine at 3,000 rpm for about 10 seconds.
5. Allow the engine to idle with the A/C ON (to create slight load) for 15 to 50 minutes.

NOTE: If the vehicle is not equipped with A/C put a slight load on the engine by doing the following:
- Securely set the parking brake.
- Block the drive wheels with wheel chocks.
- Allow the engine to idle in drive for 15 to 50 minutes.
- Confirm the status of the readiness monitor on the scan tool display.

5. OXYGEN/AIR FUEL RATIO SENSOR MONITOR (FRONT A/F SENSOR 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 DLC3 to check monitor status and preconditions (refer to step "a").
2. Start the engine and it to idle for 2 minutes or more.
3. Drive the vehicle at 40 to 70 mph (64 to 112 km/h) or more for at least 150 seconds.
4. Stop the vehicle and allow the engine to idle for 10 seconds or more.
5. Drive the vehicle at 25 mph (40 km/h) or more for at least 40 seconds.
6. Stop the vehicle and allow the engine to idle for 10 seconds or more.
7. Perform steps (5) and (6) ten times.
8. Check the status of the readiness monitor on the scan tool display. If readiness status did not switch to complete, ensure preconditions are met, turn ignition off and then repeat steps (1) through (6).

6. OXYGEN/ A/F SENSOR HEATER MONITOR