Readiness Monitor Drive Pattern
READINESS MONITOR DRIVE PATTERNPURPOSE 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 tests.
- 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 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 readiness monitor completion.
Contents:
1. CATALYST MONITOR
a. Preconditions
The monitor will not run unless:
- The Malfunction Indicator Lamp (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.
b. Drive Pattern
1. Connect the OBD II scan tool 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 did not switch to complete, ensure preconditions are met, turn the ignition switch OFF, and then repeat steps (2) and (3).
2. EVAP SYSTEM 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:
- The MIL is OFF.
- Fuel level is approximately 1/2 to 3/4 full.
- Altitude is 2,400 m (8,000 feet) 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).
c. 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 (8,000 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, "IAT - ECT" must be 7 °C (19 °F) to 11 °C (52 °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 "IAT-ECT" is less than 7 °C (19 °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 °C (19 °F) to 11 °C (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 2,400 m (8,000 feet)). Finish the drive pattern, turn the ignition switch OFF and then ON again, and repeat the drive pattern a second time.
d. 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 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.
NOTE: If the vehicle does not have A/C, put a slight electrical load on the engine by following the steps below:
- Set the parking brake securely.
- Use wheel chocks to secure the tires.
- Move the shift lever to the D position and allow engine to idle for 15 to 50 minutes.
- Check the readiness monitor status.
3. HEATED OXYGEN SENSOR MONITOR
a. Preconditions
The monitor will not run unless:
The 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 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) 10 times.
6. If readiness status does not switch to complete, ensure preconditions are met, turn ignition OFF and then repeat steps (1) through (5).
4. HEATED OXYGEN SENSOR HEATER MONITOR
a. Preconditions
The monitor will not run unless:
The 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 allow it to idle for 10 minutes 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 did not change to "complete", double-check the preconditions, turn the ignition switch OFF, and repeat steps (2) to (3).