Evaporative System Test

Evaporative System Test Outline

- To verify the problem has been fixed properly after repairs, Drive Mode 4 or evaporative system test must be performed.
- The evaporative system test, which can substitute for Drive Mode 4 as an evaporative system repair confirmation method, can be conducted while operating the NGS tester at idle instead of actually driving the vehicle.

Evaporative System Test Description

- The evaporative system test finds gas leakage in the system using the PCM to monitor negative pressure changes in the system. This test starts after sending an on-demand test signal from the NGS tester to the PCM. The PCM controls CDCV and PRGV operation and stores FTP values as follows:

1. The PCM commands the PRGV to open, which relieves the negative pressure in the evaporative system to the specified level. Then PCM commands the CDCV to close. The purpose of each valve's operation is as follows:
1. Opening the PRGV lets the negative pressure from the intake manifold into the evaporative line.
2. Closing the CDCV shuts off the evaporative line from the outside atmosphere.

2. When negative pressure in the evaporative system has reached the specified level or negative pressure relief has gone on for the specified amount of time, the PCM commands the PRGV to close and seals the system. This is to seal the evaporative system and maintain negative pressure.







3. The PCM will maintain this sealed condition for about 33 seconds while storing the FTP1 and FTP2 at each pre-set time interval.
- You can confirm whether any evaporative gas leakage occurred or not by reading the test results.

Evaporative System Malfunction Judgment

- The NGS tester calculates the stored FTP values and displays the results as follows:
1. Large leak results (DTC P0455) - FTP1
2. Small leak results (DTC P0442) - A

Evaporative System Test Procedure

NOTE: This is an alternative procedure for the dealers that cannot drive the vehicle in OBD II Drive 4 Procedure.

1. Turn the ignition switch on.




2. After setting up the NGS tester for the current vehicle, select DIAGNOSTIC DATA LINK and press TRIGGER.




3. Select PCM POWERTRAIN CONTROL MODULE and press TRIGGER.




4. Select PID/DATA MONITOR AND RECORD and press TRIGGER.




5. Press Number 5 under CLEAR to clear previously selected PIDs.

NOTE: PID screen will vary with different models.




6. Turn the menu dial clockwise to select BARO by pressing TRIGGER.




7. Turn the menu dial clockwise to select ECT, FTL volts, and IAT by pressing TRIGGER.




8. Push Number 7 under START to view PIDs.

9. Record the data values for BARO, ECT, FTL volts, IAT.
- Verify all following PIDs are within the specifications.
- If not as specified, wait until PIDs are in the specification.

NOTE: To successfully perform this procedure, all PIDs must be within the following specifications before proceeding to next step.




Specification

10. Start the engine and race it at 3,500 rpm for 200 seconds to warm it up completely.
11. Press CANCEL two times.




12. Select DIAGNOSTIC SUPPORT PROCEDURE and press TRIGGER.




13. Select SINGLE TEST and press TRIGGER.




14. Select "EVAP LEAK TEST" in second screen and press TRIGGER.




15. Press TRIGGER one more time to start the evaporative system test.

NOTE:
- The engine revolutions will increase to about 2,000 rpm in 30 to 60 seconds.
- If you depress the accelerator pedal during test, the test will stop and fail.
- If you press the CANCEL, TEST ABORTED screen appears, but engine revolutions do not decrease. Wait until engine revolutions decrease to idle.
- The NGS tester screen should show as in the figure.




16. Verify that each result is within the specifications in the table or graphs, using the BARO PID value recorded in Step 9.




17. Scroll one line.

Evaporative System Test Threshold Value







18. If NGS values are out of range, use the procedure above in DTC troubleshooting to diagnose the problem.
19. Clear pending or stored DTC.