EVAP Monitors

DRIVE PATTERN NO. 5: EVAP Monitor (Internal Pressure Monitor/Non-Intrusive Type)

Cold Soak Preconditions

The monitor will not run unless:

- MIL is OFF.

- Fuel level is between 1/2 to 3/4 full *for faster completion.*

- Altitude is 7800 feet (2400 m) or less.

IMPORTANT:
A cold soak must be performed prior to conducting the drive pattern to complete the Internal Pressure Readiness Monitor.

Cold Soak Procedure

1a. Start the engine and allow ECT (Coolant Temp) to reach 176°F (80°C) or greater. (This can be done by letting the engine idle or by driving the vehicle.)

1b. Let the vehicle cold soak for 8 hours or until the difference between IAT (Intake Air) and ECT (Coolant Temp) is less than 13°F (7°C).

- Example 1

- ECT (Coolant Temp) = 75°F (24°C).

- IAT (Intake Air) = 60°F (16°C).

- Difference between ECT (Coolant Temp) and IAT (Intake Air) is 15°F (8°C).

--> The monitor will not run because the difference between ECT (Coolant Temp) and AT (Intake Air) is greater than 13°F (7°C).

- Example 2

- ECT (Coolant Temp) = 70°F (21°C).

- IAT (Intake Air) = 68°F (20°C).

- Difference between ECT (Coolant Temp) and IAT (Intake Air) is 2°F (1°C).

--> The monitor will run because the difference between ECT (Coolant Temp) and IAT (Intake Air) is less than 13°F (7°C).

Drive Pattern Preconditions

The monitor will not run unless:

- MIL is OFF.

- Fuel level is between 1/2 to 3/4 full for *faster completion.*

- Altitude is 7800 feet (2400 m) or less.

- ECT (Coolant Temp) is between 40°F and 95°F (4.4°C - 35°C).

- IAT (Intake Air) is between 40°F and 95°F (4.4°C - 35°C).

- Cold Soak Procedure has been completed.

NOTE:
Before starting the engine, the difference between ECT (Coolant Temp) and IAT (Intake Air) must be less than 13°F (70°C). (Refer to Examples 1 and 2.)

Drive Pattern Procedure

- Connect the OBDII Scantool to DLC3 to check monitor status and preconditions.

- Release the pressure in the fuel tank by removing and then reinstalling the fuel tank cap.

- Start the engine and begin driving as directed.

NOTE:
- Do not turn the ignition off until the drive pattern is complete.

- Drive on smooth roads to reduce excessive fuel sloshing.

2a. Start the engine and as soon as safely possible begin driving at approximately 45 mph (72km/h) for 5 minutes. (Refer to the illustration.)

2b. Drive the vehicle at approximately 25 mph (40 km/h) for 15 minutes and include a minimum of two stops for approximately 30 seconds. (Refer to the illustration.)

The monitor should complete within approximately 20 minutes. It it does not, ensure preconditions are met and repeat the drive pattern process beginning with the Cold Soak Procedure.

NOTE:
The readiness status may not switch to "complete" after the first drive pattern trip if a Pending Code has been set (first trip for a two-trip DTC).

- Pending Codes are available from the DTC Info Menu in Enhanced OBDII.

- Pending Codes indicate a POTENTIAL problem was detected. A second trip is needed to confirm the DTC prior to diagnosis.

- Once a second trip is completed, a current DTC will be stored.





DRIVE PATTERN NO. 6: EVAP Monitor (Vacuum Pressure Monitor/Intrusive Type)

Cold Soak Preconditions

The monitor will not run unless:

- MIL is OFF.

- Fuel level is between 1/2 to 3/4 full *for faster completion*.

- Altitude is 7800 feet (2400 m) or less.

Cold Soak Procedure

1a. Let the vehicle cold soak for 8 hours or until the difference between IAT (Intake Air) and ECT (Coolant Temp) is less than 13°F (7°C).

- Example 1

- ECT (Coolant Temp) = 75°F (24°C).

- IAT (Intake Air) = 60°F (16°C).

- Difference between ECT (Coolant Temp) and IAT (Intake Air) is 15°F (8°C).

--> The monitor will not run because the difference between ECT (Coolant Temp) and IAT (Intake Air) is greater than 13°F (7°C).

- Example 2

- ECT (Coolant Temp) = 70°F (21°C).

- IAT (Intake Air) = 68°F (20°C).

- Difference between ECT (Coolant Temp) and IAT (Intake Air) is 2°F (1°C).

--> The monitor will run because the difference between ECT (Coolant Temp) and IAT (Intake Air) is less than 13°F (7°C).

Drive Pattern Preconditions

The monitor will not run unless:

- MIL is OFF.

- Fuel level is between 1/2 to 3/4 full *for faster completion.*

- Altitude is 7800 feet (2400 m) or less.*

- ECT (Coolant Temp) is between 40°F and 95°F (4.4°C - 35°C).

- IAT (Intake Air) is between 40°F and 95°F (4.4°C - 35°C).*

- Cold Soak Procedure has been completed.

* For 2002 MY and later 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 complete drive pattern (including Cold Soak) is repeated a second time after cycling the ignition OFF

NOTE:
Before starting the engine, the difference between ECT (Coolant Temp) and IAT (Intake Air) must be less than 13°F (7°C). (Refer to Examples 1 and 2.)

Drive Pattern Procedure

- Connect the OBDII Scantool to DLC3 to check monitor status and preconditions.

- Release the pressure in the fuel tank by removing and then reinstalling the fuel tank cap.

2a. Start the engine and allow it to idle until ECT (Coolant Temp) is 167°F (75°C) or greater. (Refer to the illustration.)

2b. Race the engine at 3,000 rpm for approximately 10 seconds. (Refer to the illustration.)

2c. Allow the engine to idle with the A/C ON (to create a slight load) for 15 - 50 minutes. (Refer to the illustration.)

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 vehicle to idle in drive for 15 - 50 minutes.

NOTE:
The readiness status may not switch to "complete" after the first drive pattern trip if a Pending Code has been set (first trip for a two-trip DTC).

- Pending Codes are available from the DTC Info Menu in Enhanced OBDII.

- Pending Codes indicate a POTENTIAL problem was detected. A second trip is needed to confirm the DTC prior to diagnosis.

- Once a second trip is completed, a current DTC will be stored.





DRIVE PATTERN NO. 7: EVAP Monitor (Without Leak Detection)

Preconditions

The monitor will not run unless:

- MIL is OFF.

- Altitude is 7800 feet (2400 m) or less.

- ECT (Coolant Temp) is 181°F (83°F) or greater. IAT (Intake Air) is 41°F (5°C) or greater.

Drive Pattern Procedure

Connect the OBDII Scantool to DLC3 to check monitor status and preconditions.

a. Drive the vehicle at 43 - 56 mph (70 - 90 km/h) for a period of 3 - 5 minutes.

NOTE:
- Do not allow the Throttle Position (TP) to exceed 30%.

- Drive with smooth throttle operation and avoid sudden acceleration.

b. Stop the vehicle and let the engine idle for 3 - 5 minutes.

c. Repeat steps "a" and "b" once.

If readiness status does not switch to "complete," ensure preconditions are met, turn the ignition OFF, then repeat steps "a" through "c."

NOTE:
The readiness status may not switch to "complete" after the first drive pattern trip if a Pending Code has been set (first trip for a two-trip DTC).

- Pending Codes are available from the DTC Info Menu in Enhanced OBDII.

- Pending Codes indicate a POTENTIAL problem was detected A second trip is needed to confirm the DTC prior to diagnosis.

- Once a second trip is completed, a current DTC will be stored.





DRIVE PATTERN NO. 8: EVAP Monitor (For Prius)

Cold Soak Preconditions

The monitor will not run unless:

- MIL is OFF.

- Altitude is 7800 feet (2400 m) or less.

IMPORTANT
A cold soak must be performed prior to conducting the drive pattern to complete the Internal Pressure Readiness Monitor.

Cold Soak Procedure

1a. Let the vehicle cold soak for 8 hours or until the difference between AT (Intake Air) and ECT (Coolant Temp) is less than 13°F (7°C).

- Example 1

- ECT (Coolant Temp) = 75°F (24°C).

- IAT (Intake Air) = 60°F (16°C).

- Difference between ECT (Coolant Temp) and IAT (Intake Air) is 15°F (8°C).

--> The monitor will not run because the difference between ECT (Coolant Temp) and IAT (Intake Air) is greater than 13°F (7°C).

- Example 2

- ECT (Coolant Temp) = 70°F (21°C).

- IAT (Intake Air) = 68°F (20°C).

- Difference between ECT (Coolant Temp) and IAT (Intake Air) is 2°F (1°C).

--> The monitor will run because the difference between ECT (Coolant Temp) and IAT (Intake Air) is less than 13°F (7°C).

Drive Pattern Preconditions

The monitor will not run unless:

- MIL is OFF.

- Altitude is 7800 feet (2400 m) or less.

- ECT (Coolant Temp) is between 40°F and 95°F (4.4°C - 35°C).

- IAT (Intake Air) is between 40°F and 95°F (4.4°C - 35°C).*

- Cold Soak Procedure has been completed.

NOTE:
Before starting the engine, the difference between ECT (Coolant Temp) and IAT (Intake Air) must be less than 13°F (7°C). (Refer to Examples 1 and 2.)

Drive Pattern Procedure

- Connect the OBDII Scantool to DLC3 to check monitor status and preconditions. Release the pressure in the fuel tank by removing and then reinstalling the fuel tank cap.

- Start the engine and as soon as safely possible begin driving as directed.

2a. Drive the vehicle at 50 - 65 mph (80 - 104 km/h) for about 15 minutes. (Refer to the illustration.)

NOTE:
- Do not turn the ignition off until the drive pattern is complete.

- Drive on smooth roads to reduce excessive fuel sloshing.

If vehicle speed drops under 45 mph (72 km/h) repeat step "2a."