P0442
DTC P0442: Evaporative Emission Control System Leak Detected (Small Leak)
TECHNICAL DESCRIPTION
- The ECM[ M/T] or PCM[ A/T] monitors the Evaporative Emission (EVAP) System pressure.
- The ECM[ M/T] or PCM[ A/T] controls the evaporative emission ventilation solenoid. It closes the evaporative emission ventilation solenoid to seal the evaporative emission canister side of the system.
- The evaporative emission purge solenoid is opened to allow manifold vacuum to create low pressure (vacuum) in the EVAP system.
- When the EVAP system develops a vacuum of 2 kPa (0.29 psi), the evaporative emission purge solenoid is closed and the fuel system vacuum is maintained at 2 kPa (0.29 psi).
- The ECM[ M/T] or PCM[ A/T] determines whether there is a leak in the EVAP system by monitoring the vacuum inside the fuel tank.
- The test is stopped when fuel vapor pressure exceeds predetermined limits.
DESCRIPTIONS OF MONITOR METHODS
- Measure reverting pressure after depressurizing by intake manifold negative pressure and detect malfunction if reverting pressure rises largely.
MONITOR EXECUTION
- Once per driving cycle.
MONITOR EXECUTION CONDITIONS (OTHER MONITOR AND SENSOR)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
- Evaporative emission purge solenoid monitor
- Evaporative emission purge system monitor
- Fuel tank differential pressure sensor monitor
- Evaporative emission ventilation solenoid monitor
- Fuel level sensor monitor
- Fuel temperature sensor monitor
Sensor (The sensors below are determined to be normal)
- Mass airflow sensor
- Barometric pressure sensor
- Intake air temperature sensor
- Engine coolant temperature sensor
LOGIC FLOW CHARTS (Monitor Sequence)
DTC SET CONDITIONS
Remaining fuel amount is 15 - 40 percent of capacity (fuel level sensor output signal voltage is 1.4 - 2.4 volts).
Check Conditions A: At Start up
- Intake air temperature is 36°C (97°F) or less when the engine is started.
- The engine coolant temperature is 36° C (97° F) or less when the engine is started.
Check Conditions B: For Test to Run
- The fuel temperature is less than 36° C (97° F), and less than 13 minutes have elapsed since the engine was started.
- Engine coolant temperature is greater than 60°C (140°F).
- Power steering pressure switch: "OFF"
- Barometric pressure is greater than 76 kPa (11 psi).
- Fuel tank differential pressure sensor output voltage is 1 to 4 volts.
- Vehicle speed is greater than or equal to 20 km/h (12.4 mph).
Check Conditions C: For Test to Stop
- Intake air temperature is greater than -10°C (14°F).
- When the evaporative emission purge solenoid and evaporative emission ventilation solenoid are closed, the pressure in the fuel tank is less than 451 Pa (0.065 psi).
- The pressure fluctuation is less than 647 Pa (0.094 psi).
- 10 seconds have elapsed since the start of the previous monitoring.
- Monitoring time: 75 - 125 seconds.
Judgement Criterion
- Internal pressure of the fuel tank has changed more than 981 Pa (0.142 psi) in 20 seconds after the tank and vapor line were closed.
NOTE:
The monitoring time (75 - 125 seconds) depends on the fuel level and the temperature in the fuel tank.
The next monitoring occurs at least 10 seconds later.
DTC SET CONDITIONS
Remaining fuel amount is 40 - 85 percent of capacity (fuel level sensor output voltage is 2.4 - 3.7 volts).
Check Conditions A: At Start up
- Intake air temperature is less than 36° C (97° F) when the engine is started.
- The engine coolant temperature is less than 36° C (97° F) when the engine is started.
Check Conditions B: For Test to Run
- The fuel temperature is less than 36° C (97° F).
- Barometric pressure is greater than 76 kPa (11 psi).
- Fuel tank differential pressure sensor output voltage is 1 to 4 volts.
Check Conditions C: For Test to Stop
- Intake air temperature is greater than -10° C (14°F).
- Engine coolant temperature is greater than 20° C (68° F).
- When the evaporative emission purge solenoid and evaporative emission ventilation solenoid are closed, the pressure in the fuel tank is less than 324 Pa (0.047 psi).
- 10 seconds have elapsed since the start of the previous monitoring.
- Monitoring time: 10 - 14 minutes.
Judgement Criterion
- Internal pressure of the fuel tank has changed more than 2 kPa (0.29 psi) in 128 seconds after the tank and vapor line were closed.
NOTE:
The monitoring time (10 - 14 minutes) depends on the fuel level and the temperature in the fuel tank.
The next monitoring occurs at least 10 seconds later.
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 5 Monitors, Trips, Drive Cycles and Readiness Codes.
TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CODE TO BE SET ARE:)
- Loose fuel cap.
- Fuel cap relief pressure is incorrect.
- Evaporative emission canister seal is leaking.
- Fuel tank, purge line or vapor line seal is leaking.
- Evaporative emission ventilation solenoid does not seal.
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A
STEP 1. Using scan tool MB991958, check the evaporative emission system monitor test.
CAUTION:
- To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
- During this test, the ECM[ M/T] or PCM[ A/T] will automatically increase the engine speed to 1,600 r/min or greater. Check that the transaxle is set to "neutral"[ M/T] or "P"[ A/T] position.
(1)Connect scan tool MB991958 to the data link connector.
(2)Turn the ignition switch to the "ON" position.
(3)Erase the DTCs using scan tool MB991958.
(4)Check that the fuel cap is securely closed (Tighten until three clicks are heard).
(5)Start the engine.
(6)Select "System Test."
(7)Select "Evap Leak Mon."
(8)During this test, keep the accelerator pedal at the idle position.
(9)Keep the engine speed and engine load within the specified range. When the monitor test starts, the "In Progress" item on scan tool MB991958 will change from "NO" to "YES."
(10) Turn the ignition switch to the "LOCK" (OFF) position, and disconnect scan tool MB991958.
Q. Is "Evap Leak Mon. Completed. Test Failed and DTCs Set" displayed on scan tool MB991958?
YES A malfunction has been detected during the monitor test. Refer to the Diagnostic Trouble Code Chart and diagnose any other DTCs that are set Multiport Fuel Injection (MFI).
If no other DTC's have been set, go to Step 2.
NO ["Evap Leak Mon. Completed. Test Passed" is displayed on scan tool MB991958.] : The evaporative emission system is working properly at this time. Explain to the customer that an improperly tightened fuel cap can cause the MIL to illuminate. Return the vehicle to the customer.
NO ["Evap Leak Mon. Discontinued. Retest again from the first" is displayed on scan tool MB991958.] : The EVAP monitor has been interrupted during the test. Turn the ignition switch to the "LOCK" (OFF) position once, and repeat the monitoring from Step 1.
STEP 2. Check the evaporative emission purge solenoid for leaks.
(1)Remove the evaporative emission purge solenoid from the intake manifold Intake Manifold Removal and Installation).
(2)Connect the hose of the hand vacuum pump to the intake manifold side nipple of the evaporative emission purge solenoid.
(3)Use the hand vacuum pump to confirm that the evaporative emission purge solenoid holds vacuum.
(4)Install the evaporative emission purge solenoid to the intake manifold Intake Manifold Removal and Installation).
Q. Does the evaporative emission purge solenoid hold vacuum?
YES Go to Step 3.
NO Replace the evaporative emission purge solenoid Intake Manifold Removal and Installation).
Then go to Step 14.
STEP 3. Check for leaks in evaporative emission hoses A and B.
(1)Use a hand vacuum pump to test each hose from hose A to hose B.
Q. Do the hoses hold vacuum?
YES Go to Step 4.
NO Replace any damaged hose. Then go to Step 14.
STEP 4. Check for leaks in the chamber.
(1)Connect a hand vacuum pump to the nipple.
(2)Plug the other nipple.
(3)Apply vacuum with the hand vacuum pump, and confirm that the applied vacuum does not fluctuate.
Q. Is the chamber in good condition?
YES Go to Step 5.
NO Replace the chamber. Then go to Step 14.
STEP 5. Check for leaks in evaporative emission hoses C through E.
(1)Use a hand vacuum pump to test each hose from hose C to hose E.
Q. Do the hoses hold vacuum?
YES Go to Step 6.
NO Replace any damaged hose. Then go to Step 14.
STEP 6. Using scan tool MB991958, check actuator test item 15: Evaporative emission ventilation solenoid.
(1)
CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
Connect scan tool MB991958 to the data link connector.
(2)Remove the rear splash shield Service and Repair).
(3)Disconnect hose E from evaporative emission canister and connect hand vacuum pump to hose E.
(4)Turn the ignition switch to the "ON" position.
(5)Set scan tool MB991958 to actuator test mode.
- Item 15: Evaporative Emission Ventilation Solenoid.
- While the evaporative emission ventilation solenoid is energized, operate the hand vacuum pump and confirm that the solenoid holds vacuum.
(6)Turn the ignition switch to the "LOCK" (OFF) position, and disconnect scan tool MB991958.
(7)Disconnect the hand vacuum pump, and connect hose E to the evaporative emission canister.
(8)Reinstall the rear splash shield Service and Repair).
Q. Did the evaporative emission ventilation solenoid hold vacuum?
YES Go to Step 7.
NO Replace the evaporative emission ventilation solenoid Service and Repair).
Then go to Step 14.
STEP 7. Pressure test the evaporative emission system lines from hoses F to I.
(1)Disconnect hose F from the evaporative emission canister, and plug hose F securely.
(2)Confirm that the evaporative emission system pressure pump (Miller number 6872A) is operating properly. Perform the self-test as described in the pump manufacturer's instructions.
(3)Remove the fuel cap.
(4)Connect the evaporative emission system pressure pump (Miller number 6872A) to the fuel tank filler tube by using fuel tank adapter (MLR-8382).
(5)Pressure test the system to determine whether any leaks are present.
NOTE:
The "Pressure test" in this procedure refers to the I/M240 Simulation Test. The eight steps of this test are described in the manufacturer's instructions for the evaporative emission system pressure pump, Miller number 6872A.
(6)Remove the evaporative emission system pressure pump (Miller number 6872A) and the fuel tank adapter (MLR-8382), and reinstall the fuel cap.
(7)Connect hose F to the evaporative emission canister.
Q. Is the evaporative emission system line free of leaks?
YES Go to Step 12.
NO Go to Step 8.
STEP 8. Check for leaks in evaporative emission hose F.
(1)Remove the rear splash shield Service and Repair).
(2)Use a hand vacuum pump to check the hose F.
Q. Do the hose hold vacuum?
YES Go to Step 9.
NO Replace any damaged hose, and reinstall the splash shield Service and Repair). Then go to Step 14.
STEP 9. Check for leaks in evaporative emission hoses G.
(1)Use a hand vacuum pump to test each hose G.
Q. Do the hoses hold vacuum?
YES Go to Step 10.
NO Replace any damaged hose. Then go to Step 14.
STEP 10. Check for leaks in evaporative emission hose H.
(1)Remove the fuel tank assembly Removal and Replacement).
(2)Use the hand vacuum pump to check the hose H.
Q. Is the hose hold vacuum?
YES Go to Step 11.
NO Replace the hose and reinstall the fuel tank assembly Removal and Replacement). Then go to Step 14.
STEP 11. Check for leaks in the fuel tank.
(1)Visually check for cracks or other leaks in the fuel tank.
NOTE:
Carefully check the fuel pump module and the fuel tank differential pressure sensor installation in the fuel tank.
(2)Connect the evaporative emission system pressure pump (Miller number 6872A) to the fuel filler hose.
(3)Plug the hose and the nipple shown in the illustration.
NOTE:
If these items are not securely plugged now, the fuel could leak in the next step.
(4)Pressurize the fuel tank with the evaporative emission system pressure pump.
(5)In the pressurized state, check for leaks by applying a soapy water solution to each section and look for bubbles.
Q. Are any leaks found?
YES [When there is a leak from the attachment points of the fuel pump module, fuel tank differential pressure sensor, fuel level sensor (sub) or leveling valve.] : Reassemble the leaked parts and check again that there are no leaks. Then reinstall the fuel tank Removal and Replacement). Then go to Step 14
.
YES [When there is a leak from the fuel tank.] : Replace the fuel tank Removal and Replacement). Go to Step 14.
NO When there is no leak, reinstall the fuel tank Removal and Replacement).
Then go to Step 13.
STEP 12. Check the evaporative emission canister for vacuum leaks.
(1)Disconnect hoses D, E and F from the evaporative emission canister side, and connect a hand vacuum pump to the evaporative emission canister instead of hose D, and plug the other nipples.
(2)Connect a hand vacuum pump to the evaporative emission canister and plug the other nipples.
(3)Apply a pressure on the hand vacuum pump, and confirm that air is maintained.
(4)Disconnect the hand vacuum pump, and connect hoses D, E and F to the canister.
Q. Is the evaporative emission canister in good condition?
YES Go to Step 13.
NO Replace the evaporative emission canister Service and Repair). Then go to Step 14 .
STEP 13. Using scan tool MB991958, check the evaporative emission system monitor test.
CAUTION:
- To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
- During this test, the ECM[ M/T] or PCM[ A/T] automatically increases the engine speed to 1,600 r/min or greater. Check that the transaxle is set to "neutral"[ M/T] or "P"[ A/T] position.
(1)Connect scan tool MB991958 to the data link connector.
(2)Turn the ignition switch to the "ON" position.
(3)Erase the DTCs using scan tool MB991958.
(4)Check that the fuel cap is securely closed (Tighten until three clicks are heard).
(5)Start the engine.
(6)Select "System Test."
(7)Select "Evap Leak Mon."
(8)During the test, keep the accelerator pedal at the idle position.
(9)Keep the engine speed and engine load within the specified range. When the monitor test starts, the "In Progress" item on scan tool MB991958 will change from "NO" to "YES."
(10)Turn the ignition switch to the "LOCK" (OFF) position. Disconnect scan tool MB991958.
Q. Is "Evap Leak Mon. Completed. Test Failed and DTCs Set" displayed on scan tool MB991958?
YES Replace the ECM [M/T] or PCM [A/T].
When the ECM [M/T] or PCM [A/T] is replaced, register the encrypted code. Encrypted Code Registration Criteria Table.
Then go to Step 14.
NO ["Evap Leak Mon. Completed. Test Passed" is displayed on scan tool MB991958.] : The evaporative emission system is working properly at this time. Go to Step 14
.
NO ["Evap Leak Mon. Discontinued. Retest again from the first" is displayed on scan tool MB991958.] : The EVAP monitor has been interrupted during the test. Turn the ignition switch to the "LOCK" (OFF) position once, and repeat the monitoring from Step 13.
STEP 14. Perform the OBD-II drive cycle.
(1)Confirm the repair by performing the appropriate drive cycle (Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 5 Monitors, Trips, Drive Cycles and Readiness Codes).
(2)Read the diagnostic trouble code (DTC).
Q. Is DTC P0442 set?
YES Repeat the troubleshooting from Step 1.
NO The procedure is complete.