How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Randall C Your Own Question

Randall C
Randall C, ASE Master Technician
Category: Dodge
Satisfied Customers: 11452
Experience:  ASE Master Tech, 32 years Diag/Electrical Specialist
13677702
Type Your Dodge Question Here...
Randall C is online now
A new question is answered every 9 seconds

How to find evap emission control system leak very small

Resolved Question:

how to find evap emission control system leak very small
Submitted: 5 years ago.
Category: Dodge
Expert:  Randall C replied 5 years ago.
HelloCustomer,, how do you know there is a evap leak, do you have a check engine light on? if so, do you have the code # lastly, not showing on my end,,, what is the year, make, model, engine? lmk Thanks
Customer: replied 5 years ago.
check engine light is on. code # XXXXX 2005 dodge stratus. my daughters car, do not know the engine.
Expert:  Randall C replied 5 years ago.
Godd start, let me check some things. Back shortly
Expert:  Randall C replied 5 years ago.
I do not need size but for sure need whether 4 cyl or 6 cyl. LMK when you can. Thanks
Customer: replied 5 years ago.
2.7 liter v6
Expert:  Randall C replied 5 years ago.

Here is everything you need to know and then some about the code. You would need a scanner and a hand vacuum pump to do the diag. Be advised, the code can set if the gas cap was not quite tight enough.

 

 

System Diagram

Connectors


DTC P0456: Evaporative Emission Control System Leak Detected (Very Small Leak)

TECHNICAL DESCRIPTION

  • The ECM or PCM monitors the Evaporative Emission (EVAP) System pressure.
  • The ECM or PCM 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 or PCM 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)

LOGIC FLOW CHARTS (Monitor Sequence)

Logic Flow Charts(Monitor Sequence)

DTC SET CONDITIONS

Test Conditions:

  • Fuel level sensor output voltage is 2.4 - 3.7 volts when the engine is started, and the amount of remaining fuel is 40 - 85 percent of capacity.
  • Engine coolant temperature is less than 36°C (97°F) when the engine is started.
  • Intake air temperature is less than 36°C (97°F) when the engine is started.
  • Engine coolant temperature is greater than 20°C (68°F).
  • Intake air temperature is greater than -10°C (14°F).
  • Fuel temperature is less than 33°C (91°F).
  • Barometric pressure is greater than 76 kPa (11 psi).
  • Fuel tank differential pressure sensor output voltage is 1 - 4 volts.
  • When the evaporative emission purge solenoid and evaporative emission ventilation solenoid are closed, the pressure rises in the fuel tank is less than 324 Pa (0.047 psi).
  • 1m10 secondshave elapsed from the start of the previous monitoring.
  • Monitoring time: 10 - 14 minutes.

Judgment Criteria:

  • Internal pressure of the fuel tank has changed greater than 1,177 - 1,373 Pa (0.177 - 0.199 psi) in 128 seconds after the tank and vapor line were closed.

OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function - OBD-II Drive Cycle - Procedure 1 - Evaporative Emission System Leak Monitor.

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 dose not seal.

OVERVIEW OF TROUBLESHOOTING

  • To determine the cause of DTC P0456, a performance test is needed. The performance test uses a mechanical vacuum gauge and scan tool MB991502 set to the data reading mode for the fuel tank differential pressure sensor (TANK PRES SNER 73). The mechanical gauge reading is used to verify the scan tool reading. A comparison of the mechanical gauge and scan tool MB991502 determines whether there is problem in the system.
  • Prior to doing the performance test, ensure that the fuel cap is closed securely. Inspect all EVAP system hoses and tubes for damage.

DIAGNOSIS
Required Special Tool:

  • MB991502: Scan Tool (MUT-II)


STEP 1. Using scan tool MB991502, check evaporative emission system monitor test.

CAUTION:

  • To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.
  • During this test, the ECM or PCM automatically increases the engine speed to 1,600 r/min or greater. Check that the transaxle is set to "neutral" or "P" position.
    1. Connect scan tool MB991502 to the data link connector.
    2. Turn the ignition switch to the "ON" position.
    3. Erase the DTCs using scan tool MB991502. (Refer to Diagnostic Function - How to Read and Erase Diagnostic Trouble Codes).
    4. Check that the fuel cap is securely closed. (Tighten until three clicks are heard).
    5. Start the engine.
    6. Select "System Test", and press the "YES" key.
    7. Select "Evap Leak Mon", and press the "YES" key.
    8. During the monitor, keep the accelerator pedal at the idling position. NOTE: If the engine speed does not reach 2,000 r/min during the monitor test, adjust the Speed Adjusting Screw (Refer to On-vehicle Service Basic Idle Speed Adjustment), and adjust to the standard value.
    9. Keep the engine speed and engine load within the specified range. When the monitor test starts, the "In Progress" item on the scan tool MB991502 will change from "NO" to "YES".
    10. Turn the ignition switch to the "LOCK" (OFF) position, and disconnect scan tool MB991502.

Q: What is displayed on the scan tool MB991507?

"Evap Leak Mon. Completed Test Passed": The evaporative emission system is working properly at this time. Explain to customer that an improperly tightened fuel cap can cause MIL to turn on. Return the vehicle to the customer.
"Evap Leak Mon. Completed. Test Failed and DTCs Set": A malfunction has been detected during the monitor test. Refer to Diagnostic Trouble Code Chart and diagnose any other DTCs that are set. If no other DTCs have been set, go to Step 2.
"Evap Lead Mon. discontinued. Retest again from the first": The EVAP monitor was 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. Disconnect hose C from the evaporative emission purge solenoid and connect a hand vacuum pump to the nipple of the evaporative emission purge solenoid.
  2. Use the hand vacuum pump to confirm that the evaporative emission purge solenoid holds vacuum.
  3. Disconnect the hand vacuum pump and connect hose C to the evaporative emission purge solenoid.

Q: Does the evaporative emission purge solenoid hold vacuum?

YES: Go to Step 3.
NO: Replace the evaporative emission purge solenoid. Then go to Step 17.


STEP 3. Check for leaks in the evaporative emission system hoses A through E. Perform a leakage test with a hand vacuum pump on each hose from hose A to hose E.

Q: Does the hoses hold vacuum?

YES: Go to Step 4.
NO: Replace any damaged hose. Then go to Step 17.




STEP 4. Check the evaporative emission ventilation solenoid using scan tool MB991502. (Actuator test item 29).

CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.

  1. Connect scan tool MB991502 to the data link connector.
  2. Remove the module bracket mounting bolts and disconnect hose G from the evaporative emission ventilation solenoid.
  3. Connect the hand vacuum pump to the nipple of the evaporative emission ventilation solenoid from which the hoses have been disconnected.
  4. Turn the ignition switch to the "ON" position.
  5. Set scan tool MB991502 to actuator test mode for item 29: Evaporative Emission Ventilation Solenoid. While the evaporative emission ventilation solenoid is energized, operate the hand vacuum pump and confirm that solenoid holds vacuum.
  6. Turn the ignition switch to the "LOCK" (OFF) position, and disconnect scan tool MB991502.
  7. Disconnect the hand vacuum pump and connect hose G to the evaporative emission ventilation solenoid, and install the module bracket mounting bolts.

Q: Does the evaporative emission ventilation solenoid hold vacuum?

YES: Go to Step 5.
NO: Replace the evaporative emission ventilation solenoid.(Refer to Evaporative Emission Canister and Fuel Tank Pressure Relief Valve). Then go to Step 17.



STEP 5. Pressure test the evaporative emission system lines between hose F and P.

  1. Remove the module bracket mounting bolts and disconnect hose G from the evaporative emission ventilation solenoid, and plug the hose G.
  2. Confirm that the evaporative emission system pressure pump (Miller number 6872A) is operating properly. Perform the self-test as described in the manufacturer's instructions.
  3. Connect an evaporative emission system pressure pump to the fuel filler neck.
  4. 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.
  5. Connect hose G to the evaporative emission ventilation solenoid and install the module bracket mounting bolts.

Q: Is the evaporative emission system line free of leaks?

YES: Go to Step 16.
NO: Go to Step 6.


STEP 6. Pressure test the evaporative emission system lines between hose I and P.

  1. Remove the module bracket mounting bolts and disconnect hose I at the evaporative emission canister side, and plug the hose I securely.
  2. Perform the evaporative emission system pressure test.
  3. Disconnect the evaporative emission system pressure pump and reinstall the fuel cap.
  4. Connect hose I and install the module bracket mounting bolts.

Q: Is the evaporative emission system line free of leaks?

YES: Go to Step 7.
NO: Go to Step 9.


STEP 7. Check for leaks in the evaporative emission system hoses F through H.

  1. Remove the fuel tank.
  2. Perform a leakage test with a hand vacuum pump on each hose from hose F to hose H.

Q: Does the hoses hold vacuum?

YES: Go to Step 8.
NO: Replace any damaged hose and reinstall the fuel tank. Then go to Step 17.


STEP 8. Check for leaks in the evaporative emission canister.

  1. Connect a hand vacuum pump to the vent nipple of the evaporative emission canister.
  2. Plug the other two nipples or loop a hose between them.
  3. Apply vacuum with the hand vacuum pump and confirm that the canister holds vacuum.

Q: Does the evaporative emission canister hold vacuum?

YES: Go to Step 17.
NO: Replace the evaporative emission canister (Refer to Evaporative Emission Canister and Fuel Tank Pressure Relief Valve) and reinstall the fuel tank. Then go to Step 17.



STEP 9. Check for leaks in the evaporative emission system lines between hose J and K.

  1. Remove the fuel filler neck protector.
  2. Disconnect hose J at the liquid separator side and connect a hand vacuum pump to the hose J.
  3. Disconnect hose K at the fuel tank and plug the hose K securely.
  4. Apply vacuum with the hand vacuum pump and confirm that the vacuum holds.
  5. Disconnect the hand vacuum pump and connect hose K to the fuel tank.

Q: Does the evaporative emission system lines hold vacuum?

YES: Go to Step 10.
NO: Replace any damaged hose and reinstall the fuel filler neck protector. Then go to Step 17.



STEP10. Check for leaks in the evaporative emission system hoses I, L, M, N and O.

  1. Remove the fuel tank and fuel filler neck assembly.
  2. Perform a leakage test with a hand vacuum pump on each of hose I, L, M, N and O.

Q: Does the hoses hold vacuum?

YES: Go to Step 11.
NO: Replace any damaged hose, and reinstall the fuel tank and fuel filler neck assembly. Then go to Step 17.



STEP 11. Check the check valve A.

  1. Check valve A is an one-way check valve.
  2. Check valve A should allow air to flow in only one direction.

Q: Does check valve A allow air to flow in one direction only?

YES: Go to Step 12.
NO: Replace check valve A, and reinstall the fuel tank and fuel filler neck assembly. Then go to Step 17.



STEP 12. Check the check valve B.

  1. Check valve B is an one-way check valve.
  2. Check valve B should allow air to flow in only one direction.

Q: Does check valve B allow air to flow in one direction only?

YES: Go to Step 13.
NO: Replace check valve B, and reinstall the fuel tank and fuel filler neck assembly. Then go to Step 17.


STEP 13. Check for leaks in the evaporative emission system hose P. Perform a leakage test with a hand vacuum pump on hose P.

Q: Does hose P hold vacuum?

YES: Go to Step 14.
NO: Replace the hose P, and reinstall the fuel tank and fuel filler neck assembly. Then go to Step 17.

STEP 14. Check for cracks in the fuel filler neck assembly. Visually check for cracks in the fuel filler neck assembly.

Q: Is the fuel filler neck assembly in good condition?

YES: Go to Step 15.
NO: Replace the fuel filler neck assembly, and reinstall the fuel tank and fuel filler neck assembly. Then go to Step 17.




STEP 15. Check for leaks in the fuel tank.

  1. Visually check for cracks and leaks, etc. NOTE: Carefully check the fuel pump assembly and the differential pressure sensor installation in the fuel tank.
  2. Connect an evaporative emission system pressure pump to the leveling valve nipple.
  3. Plug the filler hose, feed pipe, return pipe and rollover valve nipple that are connected to the fuel tank. NOTE: If these items are not securely plugged at this time, the fuel could leak from the tank.
  4. Pressurize the fuel tank with the evaporative emission system pressure pump.
  5. In the pressurized state, check for the leaks by applying soapy water solution to each section and look for bubbles.

Q: Is the fuel tank free of leaks?

YES: Go to Step 16.
NO: Replace the fuel tank, and reinstall the fuel tank and fuel filler neck assembly. Then go to Step 17.


STEP 16. Using scan tool MB991502, check evaporative emission system monitor test.

CAUTION:

Q: What is displayed on the scan tool MB991507?

"Evap Leak Mon. Completed. Test Passed": The evaporative emission system is working properly at this time. Go to Step 17.
"Evap Leak Mon. Completed. Test Failed and DTCs Set": Replace the ECM or PCM . Then go to Step 17.
"Evap Lead Mon. discontinued. Retest again from the first": The monitor test was interrupted. Turn the ignition switch to the "LOCK" (OFF) position once and repeat evaporative emission system monitor test.

STEP 17. Perform the OBD-II drive cycle.

  1. Confirm the repair by performing the appropriate drive cycle (Refer to Diagnostic Function - OBD-II Drive Cycle - Procedure 1 - Evaporative Emission System Leak Monitor).
  2. Read the DTC.

Q: Is DTC P0456 set?

YES: Repeat the troubleshooting procedure. Go to Step 1.
NO: The procedure is complete.

 

 

Randall C, ASE Master Technician
Category: Dodge
Satisfied Customers: 11452
Experience: ASE Master Tech, 32 years Diag/Electrical Specialist
Randall C and 5 other Dodge Specialists are ready to help you

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • I AM VERY GLAD THAT I TOOK A CHANCE ON YOUR PROBLEM SOLVING SKILLS. I WAS SUCCESSFUL IN REPLACING THE FUEL PUMP. MY TRUCK RUNS LIKE A CLOCK. IT RUNS LIKE THE DAY I BOUGHT IT. NO LUNGING FORWARD, THE TURBO REACTS THE SECOND I STOMP ON THE GAS, AND IT HAS A LOT MORE POWER AND EVEN SOUNDS BETTER TO ME. IT SAVED ABOUT $500.00 BY DOING THE WORK MYSELF. I GIVE YOU ALL THE CREDIT FOR YOUR DIAGNOSING THE PROBLEM, JUST FROM THE SYMPTONS I GAVE YOU OVER THE e MAIL. I WILL USE YOUR WEB SITE AGAIN AND REFER MY FRIENDS. THANKS SO MUCH FOR THE HELP. TOM WHITTAKER USA
< Last | Next >
  • I AM VERY GLAD THAT I TOOK A CHANCE ON YOUR PROBLEM SOLVING SKILLS. I WAS SUCCESSFUL IN REPLACING THE FUEL PUMP. MY TRUCK RUNS LIKE A CLOCK. IT RUNS LIKE THE DAY I BOUGHT IT. NO LUNGING FORWARD, THE TURBO REACTS THE SECOND I STOMP ON THE GAS, AND IT HAS A LOT MORE POWER AND EVEN SOUNDS BETTER TO ME. IT SAVED ABOUT $500.00 BY DOING THE WORK MYSELF. I GIVE YOU ALL THE CREDIT FOR YOUR DIAGNOSING THE PROBLEM, JUST FROM THE SYMPTONS I GAVE YOU OVER THE e MAIL. I WILL USE YOUR WEB SITE AGAIN AND REFER MY FRIENDS. THANKS SO MUCH FOR THE HELP. TOM WHITTAKER USA
  • Just a quick line to tell you how pleased I am to have my brakes working properly after all this time. Your answer was what I needed. I would certainly recommend you highly. God bless! Rev. Jerry Baysinger Holts Summit, Mo
  • I recently asked a question about my 2005 dodge ram, and I just wanted to let my Expert know that he hit the nail squarely on the head with his answer. I wanted to thank him again. Greg Pittsburgh, PA
  • Just a quick line to tell you how pleased I am to have my brakes working properly after all this time. Your answer was what I needed. I would certainly recommend you highly. God bless! Jerry Holts Summit, MO
  • I was skeptical at first but thought I'd give it a try. I was pleasantly surprised. Your site actually is a quality service that I would recommend to others in a heartbeat. Stan Sayre, PA
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
 
 
 

Meet The Experts:

 
 
 
  • Jerry

    Master Mechanic

    Satisfied Customers:

    1227
    ASE Master tech, 30 years exp. troubleshooter, driveability tech
< Last | Next >
  • http://ww2.justanswer.com/uploads/SU/supermechanic/2013-8-23_03546_500.64x64.jpg Jerry's Avatar

    Jerry

    Master Mechanic

    Satisfied Customers:

    1227
    ASE Master tech, 30 years exp. troubleshooter, driveability tech
  • http://ww2.justanswer.com/uploads/MO/MoparCertified/2012-6-7_4142_mechanic.64x64.jpg Mopar Certified's Avatar

    Mopar Certified

    Dodge Technician

    Satisfied Customers:

    5813
    24 Year Chrysler/Dodge Certified Specialist
  • http://ww2.justanswer.com/uploads/jeep10000/2008-9-18_222938_192601.jpg Chris's Avatar

    Chris

    Shop Foreman

    Satisfied Customers:

    4041
    ASE and Chrysler Certified Master Tech
  • http://ww2.justanswer.com/uploads/ke4ich/2009-08-12_212931_DSC02211.JPG moparfl's Avatar

    moparfl

    ASE Certified Technician

    Satisfied Customers:

    3285
    ASE Master Tech Gold level Chrysler Status 30 years dealership exp
  • http://ww2.justanswer.com/uploads/DO/dodgerench/2012-8-1_1142_IMG3173.64x64.JPG Dodgerench's Avatar

    Dodgerench

    ASE Certified Technician

    Satisfied Customers:

    2480
    30+ years Dodge/Chrysler exp., ASE Master with L1 certification. Driveability/ combustion specialist
  • http://ww2.justanswer.com/uploads/RO/rodcuda/2011-7-25_224114_Donhoff1.64x64.JPG Neal's Avatar

    Neal

    Dodge Mechanic

    Satisfied Customers:

    1870
    30 years experience in Dodge Chrysler and Plymouth
  • http://ww2.justanswer.com/uploads/tsmodie/2009-6-10_144056_tim.jpg Tim Mohr's Avatar

    Tim Mohr

    ASE MASTER TECH

    Satisfied Customers:

    1664
    30 YRS EXPERIENCE, FOREIGN AND DOMESTIC, GAS AND DEISEL
 
 
 
Chat Now With A Dodge Mechanic
Randall C
Randall C
Auto Technician / Consultant
1122 Satisfied Customers
ASE Master Tech, 32 years Diag/Electrical Specialist