GrandCaravan 2008

Evaporative Emission Control System

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EVAP Canister



Operation

Specific to:

Chrysler Town & Country 2008-2009

Dodge Grand Caravan 2008-2009

The Evaporative Emissions (EVAP) Canister is the primary component in the Evaporative Emission (EVAP) Control System that prevents the evaporation of unburned fuel vapors (Hydrocarbons) from being released into the atmosphere. The EVAP canister contains a charcoal element for the filtering of hydrocarbons, and the filtered Carbon Dioxide (CO2) is then vented to atmosphere when the vehicle is not in operation. The canister also contains a number of ports, which provide for the redistribution of hydrocarbons into the fuel tank when the vehicle is in operation through the purge control system.

Removal & Installation

Specific to:

Chrysler Town & Country 2008-2009

Dodge Grand Caravan 2008-2009


CAUTION
The fuel system is under constant pressure even with engine OFF. Before servicing any part of the fuel system, the pressure must be released.

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove the fuel cap.
  4.  
  5. Release the pressure in the fuel system.
  6.  
  7. Remove the hose clamp and remove the fuel fill hose from the fuel tank.
  8.  
  9. Disconnect the fuel pump electrical connector from the body harness connector.
  10.  
  11. Disconnect the fuel line quick connect fitting (1) and the evaporator hose quick connect fitting (2).

    Click image to see an enlarged view

    Fig. Disconnect the fuel line quick connect fitting (1) and the evaporator hose quick connect fitting (2)

  12.  
  13. Disconnect the electrical connector (1) from the Evaporative System Integrity Monitor (ESIM) switch (2).
  14.  
  15. Disconnect the fuel fill vapor hose from the fuel tank control valve hose.
  16.  
  17. Disconnect the fresh air hose (3) from the ESIM switch (2).
    WARNING
    Support the fuel tank with a transmission jack, or equivalent. Use straps to secure the fuel tank to the jack. Failure to properly support and secure the fuel tank during removal may cause fuel to spill or the fuel tank to fall from the jack assembly.



    Click image to see an enlarged view

    Fig. Location of Evaporative System Integrity Monitor (ESIM) switch

  18.  
  19. Loosen the front fuel tank strap bolts (3), do not remove.
  20.  
  21. Loosen the rear fuel tank strap bolts (3), do not remove.
  22.  
  23. Remove the vapor canister bracket bolt (1).
  24.  
  25. Lower the fuel tank enough to remove the vapor canister bracket.

    Click image to see an enlarged view

    Fig. Loosen the fuel tank strap bolts and remove the vapor canister bracket bolt

  26.  
  27. Disconnect the vapor canister quick connector (1) from the vapor line.
  28.  
  29. Disconnect the vapor canister quick connector (3) from the fuel tank control valve.
  30.  
  31. Remove the vapor canister (2).

    Click image to see an enlarged view

    Fig. Evaporative Emissions (EVAP) canister location

  32.  

To install:

  1. Install the vapor canister (2).
  2.  
  3. Connect the vapor canister quick connector (3) to the fuel tank control valve.
  4.  
  5. Connect the vapor canister quick connector (1) to the vapor line.
  6.  
  7. Raise the fuel tank into vehicle position.
  8.  
  9. Install the vapor canister bracket bolt (1). Tighten to 40 ft. lbs. (54 Nm).
  10.  
  11. Tighten all fuel tank strap bolts (3) to 40 ft. lbs. (54 Nm).
  12.  
  13. Connect the fresh air hose (3) to the ESIM switch (2).
  14.  
  15. Connect the electrical connector (1) to the ESIM switch (2).
  16.  
  17. Connect the fuel line quick connect fitting (1) and the evaporator hose quick connect fitting (2).
  18.  
  19. Connect the body harness connector.
  20.  
  21. Install the fuel fill hose and the hose clamp to the fuel tank. Tighten the clamp.
  22.  
  23. Install the fuel cap.
  24.  
  25. Use the scan tool ASD Fuel System Test to pressurize the fuel system. Check for leaks.
  26.  

Testing

Specific to:

Chrysler Town & Country 2008-2009

Dodge Grand Caravan 2008-2009

  1. The vapor/vacuum lines and hoses must be firmly connected.
  2.  
  3. Check the vapor/vacuum lines at the ESIM switch, filter, and EVAP canister purge solenoid for damage or leaks.
  4.  
  5. If a leak is present, a Diagnostic Trouble Code (DTC) may be set. Check for DTC-s.
  6.  
  7. Check the EVAP canister for the following:

    Cracks at the housing
     
    Fuel saturation
     

  8.  

Related Diagnostic Trouble Codes

Specific to:

Chrysler Town & Country 2008-2009

Dodge Grand Caravan 2008-2009



Click image to see an enlarged view

Fig. Related Diagnostic Trouble Codes

System Diagnostics

Specific to:

Chrysler Town & Country 2008-2009

Dodge Grand Caravan 2008-2009

When testing the EVAP system for proper operation, there should always be a pressure differential between the fuel tank pressure and atmospheric pressure. If any of the tests reveal a pressure differential of less than .02- Hg (.067 kPa/.5mm Hg), the Powertrain Control Module (PCM) will interpret this condition as a leak.

  1. Verify the condition of the EVAP system by performing the following visual inspections:

    Ensure that the fuel filler cap is installed and properly secured.
     
    Inspect the charcoal canister for physical damage such as cracks, broken or cracked fittings, damage from road debris, or rodent damage.
     
    Inspect all EVAP control devices (EVAP and purge control system monitors, controllers, and actuators) for physical damage such as cracks, broken or cracked fittings, damage from road debris, or rodent damage.
     
    Inspect all hoses and vacuum line connections for proper routing and placement.
     
    Inspect all electronic control devices for proper electrical connections.
     
    Inspect the condition of all fittings and seals for damage, drying, or wear.
     
    Inspect the condition of all hoses and vacuum lines for displacement, damage, or wear.
     

  2.  

If any physical defects are evident, verify the operation of any questionable components before replacement.

  1. Verify the operation of the EVAP system by performing any or all the following tests:

    Using a suitable scan tool, perform an actuator (active) test to verify the correct operation of EVAP control devices (EVAP and purge control system monitors, controllers, and actuators).
     
    Using a smoke machine, verify that the EVAP system does not exhibit any physical leaks.
     
    Using a suitable EVAP system pressure tester, verify that the EVAP system is properly sealed against positive and negative pressure.
     
    Using a suitable EVAP system pressure tester along with a suitable scan tool, monitor the EVAP pressure under positive and negative pressure conditions.
     

  2.  

EVAP Purge Solenoid



Description & Operation

Specific to:

Chrysler Town & Country 2008-2009

Dodge Grand Caravan 2008-2009

The Evaporative Emissions (EVAP) Control System prevents the evaporation of unburned fuel vapors (Hydrocarbons) from being released into the atmosphere. The Evaporative Emissions (EVAP) Canister contains a charcoal element for the filtering of hydrocarbons, and the filtered Carbon Dioxide (CO2) is then vented to atmosphere when the vehicle is not in operation.

When the vehicle is in operation, the Evaporative Emissions (EVAP) Purge Control Solenoid draws the unburned fuel vapors back into the fuel tank so that the hydrocarbons can be condensed, and redistributed to the engine for correct burning.

Removal & Installation

Specific to:

Chrysler Town & Country 2008-2009

Dodge Grand Caravan 2008-2009

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove the air box cover to gain access to the evaporator purge solenoid.
  4.  
  5. Disconnect the electrical connector (1) from the evaporator purge solenoid (5).
  6.  
  7. Remove the purge hose (2) from the evaporator purge solenoid (5).
  8.  
  9. Remove the quick connect fuel tank hose (4) from the evaporator purge solenoid (5).
  10.  
  11. Remove the nut (3) and the evaporator purge solenoid (5).

    Click image to see an enlarged view

    Fig. Evaporative Emissions (EVAP) purge control solenoid location

  12.  

To install:

  1. Install the evaporator purge solenoid (5) and the nut. Tighten to 90 inch lbs. (10 Nm).
  2.  
  3. Install the quick connect fuel tank hose (4) to the evaporator purge solenoid (5).
  4.  
  5. Install the purge hose (2) to the evaporator purge solenoid (5). Make sure the plastic clip for the purge hose (2) is connected.
  6.  
  7. Connect the electrical connector (1) to the evaporator purge solenoid (5).
  8.  
  9. Install the air box cover.
  10.  

Testing

Specific to:

Chrysler Town & Country 2008-2009

Dodge Grand Caravan 2008-2009

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Turn the Ignition ON, engine not running.
  4.  
  5. Using a 12-volt test light connected to a ground, check the EVAP purge control circuit in the EVAP purge solenoid harness connector.
    NOTE
    The DTC needs to be cleared before actuating the purge solenoid, if present. If the DTC is not cleared, the solenoid may not be allowed to actuate.

  6.  
  7. With the scan tool, actuate the EVAP purge solenoid control to the ON 100 percent position.
  8.  
  9. The test light should be illuminated and brighten proportional to the maximum duty cycle allowed by the scan tool. For example, if the scan tool allows 100 percent actuation, the brightness should be as bright as a direct connection to the battery. If the scan tool allows a maximum 25 percent actuation, the brightness should be 25 percent as bright as a direct connection to the battery.
  10.  
  11. If the light was illuminated and bright, observe the following, verify that there is good pin-to-terminal contact in the Solenoid and PCM connectors. If necessary, replace the EVAP Purge Solenoid.
  12.  

Connection & Wiring Diagnosis

Specific to:

Chrysler Town & Country 2008-2009

Dodge Grand Caravan 2008-2009

Refer to the Electrical Wiring Diagram for component and connector locations, connector views, and circuit-specific information.

Many intermittent open or short circuits may be caused by wiring harness and connector movement due to vibration, engine torque, bumps and rough pavement, etc.

  1. Test the wiring harness and connectors by performing the following tests:

    Move the related connectors and wiring while monitoring the appropriate scan tool data.  
     
    Move the related connectors and wiring with the component commanded ON and OFF. Using a suitable the scan tool, observe the component operation.
     
    With the engine running, move the related connectors and wiring while monitoring component operation.
     
    If harness or connector movement affects the data displayed, the component and system operation, or the engine operation, inspect and repair the harness or connections as necessary.
     

  2.  
  3. Test the connector terminal pins and/or wiring by performing the following tests:

    Inspect for incorrect mating of the connector halves, or terminals not fully seated in the connector body.  
     
    Inspect for improperly formed or damaged terminals and test for incorrect terminal tension.  
     
    Inspect for poor terminal to wire connections including terminals crimped over insulation. This requires removing the terminal from the connector body.  
     
    Inspect for corrosion or water intrusion. Pierced or damaged insulation can allow moisture to enter the wiring. The conductor can corrode inside the insulation with little visible evidence. Look for swollen and/or brittle sections of wire in the suspect circuits.  
     
    Inspect for wires that are broken inside the insulation by gently pulling on suspect sections of wiring.
     

  4.  

Diagnostics

Specific to:

Chrysler Town & Country 2008-2009

Dodge Grand Caravan 2008-2009

When testing the EVAP system for proper operation, there should always be a pressure differential between the fuel tank pressure and atmospheric pressure. If any of the tests reveal a pressure differential of less than .02- Hg (.067 kPa/.5mm Hg), the Powertrain Control Module (PCM) will interpret this condition as a leak.

  1. Verify the condition of the EVAP system by performing the following visual inspections:

    Ensure that the fuel filler cap is installed and properly secured.
     
    Inspect the charcoal canister for physical damage such as cracks, broken or cracked fittings, damage from road debris, or rodent damage.
     
    Inspect all EVAP control devices (EVAP and purge control system monitors, controllers, and actuators) for physical damage such as cracks, broken or cracked fittings, damage from road debris, or rodent damage.
     
    Inspect all hoses and vacuum line connections for proper routing and placement.
     
    Inspect all electronic control devices for proper electrical connections.
     
    Inspect the condition of all fittings and seals for damage, drying, or wear.
     
    Inspect the condition of all hoses and vacuum lines for displacement, damage, or wear.
     

  2.  

If any physical defects are evident, verify the operation of any questionable components before replacement.

  1. Verify the operation of the EVAP system by performing any or all the following tests:

    Using a suitable scan tool, perform an actuator (active) test to verify the correct operation of EVAP control devices (EVAP and purge control system monitors, controllers, and actuators).
     
    Using a smoke machine, verify that the EVAP system does not exhibit any physical leaks.
     
    Using a suitable EVAP system pressure tester, verify that the EVAP system is properly sealed against positive and negative pressure.
     
    Using a suitable EVAP system pressure tester along with a suitable scan tool, monitor the EVAP pressure under positive and negative pressure conditions.
     

  2.  

Related Diagnostic Trouble Codes (DTC)

Specific to:

Chrysler Town & Country 2008-2009

Dodge Grand Caravan 2008-2009



Click image to see an enlarged view

Fig. Related Diagnostic Trouble Codes

EVAP System Integrity Monitor



Operation

Specific to:

Chrysler Town & Country 2008-2009

Dodge Grand Caravan 2008-2009


WARNING
No liquids of any kind should ever be put into the ESIM assembly. If liquids enter the system this will damage the components and may set fault codes.


NOTE
The ESIM is not serviceable, this break down is used for information only.

The Evaporative System Integrity Monitor (ESIM) is very similar to the NVLD. However, the design of the ESIM has been simplified and unlike the NVLD the ESIM does not require a solenoid. The ESIM mounts directly to the canister, eliminating the need for a mounting bracket. It is critical that the ESIM is mounted vertically. On vehicles where the canister is mounted on an angle, the ESIM requires an adaptor to maintain a vertical position. When the ESIM is installed vertically, the electrical connector is in the 3 o'clock position.

The ESIM, while physically different than the NVLD system, performs the same basic function as the NVLD does-controlling evaporative emissions. The ESIM has been simplified because the solenoid used on the NVLD is not used on the ESIM.

The ESIM consists of housing, 2 check valves (sometimes referred to as weights), a diaphragm, a switch, and a cover. The larger check valve seals for pressure and the smaller one seals for vacuum. During refueling, pressure is built up in the evaporative system. When pressure reaches approximately 0.5 inches of water, the large check valve unseats and the pressure vents to the fresh air filter.

Conversely, when the system cools, the resulting vacuum lifts the small check valve from its seat and allows fresh air to enter the system and relieves the vacuum condition. When a calibrated amount of vacuum is achieved in the evaporative system, the diaphragm is pulled inward, pushing on the spring and closing the contacts.

The ESIM conducts tests on the evaporative system as follows: An engine OFF, non-intrusive test for small leaks, and an engine running, intrusive test for medium/large leaks.

The ESIM weights seal the EVAP system during engine OFF conditions. If the EVAP system is sealed, it will be pulled into a vacuum, either due to the cool down from operating temperature or during ambient temperature cycling. When the vacuum in the system exceeds about 1 inch H20, the vacuum switch closes. The switch closure sends a signal to the PCM. In order to pass the non-intrusive small leak test, the ESIM switch must close within a calculated amount of time and within a specified amount of key-OFF events.

If the ESIM switch does not close as specified, the test is considered inconclusive and the intrusive engine running test will be run during the next key-ON cycle. This intrusive test will run on the next cold engine running condition.

Click image to see an enlarged view

Fig. ESIM system operational view

The conditions for running the intrusive test are:



After the vehicle is started, the engine coolant temperature must be within 50° F (10° C) of the ambient temperature to indicate a cold start
 
The fuel level must be between 12-88 percent
 
The engine must be in closed loop
 
Manifold vacuum must be greater than a minimum specified value
 
Ambient temperature must be between 39-98° F (4-37° C) and the elevation level must be below 8,500 feet (2,591 meters).
 

The test is accomplished by the PCM activating the purge solenoid to create a vacuum in the evaporative system. The PCM then measures the amount of time it takes for the vacuum to dissipate. This is known as the vacuum decay method. If the switch opens quickly a large leak is recorded. If the switch opens after a predetermined amount of time, then the small leak matures. If the switch does not close, then a general evaporative failure is recorded. The purge monitor tests the integrity of the hose attached between the purge valve and throttle body/intake. The purge monitor is a 2 stage test and it runs only after the evaporative system passes the small leak test.

Even when all of the thresholds are met, a small leak will not be recorded until after the medium/large leak monitor has been run. This is accomplished by the PCM activating the purge solenoid to create a vacuum in the evaporative system. If the medium/large leak test runs and the ESIM switch does not close, a general evaporative test is run. The purge solenoid is activated for approximately 10 seconds, increasing the amount of vacuum in the system. If the ESIM switch closes after the extended purge activation, a large leak fault is generated. If the switch does not close, a general evaporative system fault is generated.

The purge monitor tests the integrity of the hose attached between the purge valve and throttle body/intake. The purge monitor is a 2-stage test and it runs only after the evaporative system passes the small leak test.

Stage 1 of the purge monitor is non-intrusive. The PCM monitors the purge vapor ratio. If the ratio is above a calibrated specification, the monitor passes. Stage 2 is an intrusive test and it runs only if stage 1 fails. During the stage 2 test, the PCM commands the purge solenoid to flow at a specified rate to force the purge vapor ratio to update. The vapor ratio is compared to a calibrated specification and if it is less than specified, a one-trip failure is recorded.

The ESIM switch stuck closed monitor checks to see if the switch is stuck closed. This is a power down test that runs at key-OFF; when the PCM sees 0 RPM-s, the purge solenoid is energized for a maximum of 30 seconds, venting any vacuum trapped in the evaporative system. If the switch opens, or was open before the test began, the monitor passes. If the switch does not open, the monitor fails. This is a 2-trip MIL. The star scan tool can be used to force the ESIM switch stuck closed monitor to run.

The PCM also uses the ESIM to detect a loose or missing gas cap. The PCM controller looks for a change in the fuel level (25 percent minimum). If a medium/large leak is detected, the Malfunction Indicator Lamp (MIL) illuminates and a pending 1-trip fault code is set. On the PCM, this is a 3-trip fault before the code matures.

Removal & Installation

Specific to:

Chrysler Town & Country 2008-2009

Dodge Grand Caravan 2008-2009

The EVAP System Integrity Monitor (ESIM) switch is attached to the EVAP canister and is usually not serviceable. Replace the switch by replacing the EVAP canister. Refer to Evaporative Emissions (EVAP) Canister, removal & installation.

The ESIM switch (3) is located on the vapor canister (1).


NOTE
Clean the area around the ESIM switch prior to removal.

If servicing the ESIM switch separately, refer to the following:

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Disconnect the electrical connector (5) from the ESIM switch (3).
  4.  
  5. Remove the vapor canister filter line (4) from the ESIM switch (3).
  6.  
  7. Push the lock tab (2) towards the ESIM switch (3) and rotate it 1 / 4 turn counterclockwise to remove it from the vapor canister (1).

    Click image to see an enlarged view

    Fig. EVAP System Integrity Monitor (ESIM) switch location

  8.  

To install:


NOTE
The fresh air lines and hoses from the ESIM must have a clear opening to the atmosphere. Check the fresh air lines, including the fresh air filter, for obstructions or restrictions at the ESIM. Also, check the routing to the exit to atmosphere. If a restriction is present, the system will not allow free flow passage of clean air, and an early shut-off of the fuel fill nozzle may occur during fuel fill.


NOTE
After installing ESIM switch, the electrical connector on the switch must be in the 3 o'clock position. This step must be done for proper ESIM switch operation.

  1. Install the ESIM switch (3) to the vapor canister (1) and rotate it 1 / 4 turn clockwise until the lock tab (2) engages. Make sure the electrical connector is in the 3 o'clock position.
  2.  
  3. Install the vapor canister filter line (4) to the ESIM switch (3).
  4.  
  5. Connect the electrical connector (5) to the ESIM switch (3).
  6.  

Testing

Specific to:

Chrysler Town & Country 2008-2009

Dodge Grand Caravan 2008-2009

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Perform a visual and physical inspection of the entire EVAP system.
  4.  
  5. Check for the following conditions:

    Hoses disconnected or left off
     
    Holes or cracks
     
    Loose seal points
     
    Evidence of damaged components
     
    Incorrect routing of hoses and tubes
     
    Fuel Cap left off or bad gasket seal
     

  6.  
  7. With a scan tool check to see if any DTC-s are present.
  8.  
  9. To continue testing, an Evaporative Emission Leak Detector is required. Follow the manufacturer-s instructions for use of the detector.
  10.  

Connection And Wiring Diagnosis

Specific to:

Chrysler Town & Country 2008-2009

Dodge Grand Caravan 2008-2009

Refer to the Electrical Wiring Diagram for component and connector locations, connector views, and circuit-specific information.

Many intermittent open or short circuits may be caused by wiring harness and connector movement due to vibration, engine torque, bumps and rough pavement, etc.

  1. Test the wiring harness and connectors by performing the following tests:

    Move the related connectors and wiring while monitoring the appropriate scan tool data.  
     
    Move the related connectors and wiring with the component commanded ON and OFF. Using a suitable the scan tool, observe the component operation.
     
    With the engine running, move the related connectors and wiring while monitoring component operation.
     
    If harness or connector movement affects the data displayed, the component and system operation, or the engine operation, inspect and repair the harness or connections as necessary.
     

  2.  
  3. Test the connector terminal pins and/or wiring by performing the following tests:

    Inspect for incorrect mating of the connector halves, or terminals not fully seated in the connector body.  
     
    Inspect for improperly formed or damaged terminals and test for incorrect terminal tension.  
     
    Inspect for poor terminal to wire connections including terminals crimped over insulation. This requires removing the terminal from the connector body.  
     
    Inspect for corrosion or water intrusion. Pierced or damaged insulation can allow moisture to enter the wiring. The conductor can corrode inside the insulation with little visible evidence. Look for swollen and/or brittle sections of wire in the suspect circuits.  
     
    Inspect for wires that are broken inside the insulation by gently pulling on suspect sections of wiring.
     

  4.  

Diagnostics

Specific to:

Chrysler Town & Country 2008-2009

Dodge Grand Caravan 2008-2009

When testing the EVAP system for proper operation, there should always be a pressure differential between the fuel tank pressure and atmospheric pressure. If any of the tests reveal a pressure differential of less than .02- Hg (.067 kPa/.5mm Hg), the Powertrain Control Module (PCM) will interpret this condition as a leak.

  1. Verify the condition of the EVAP system by performing the following visual inspections:

    Ensure that the fuel filler cap is installed and properly secured.
     
    Inspect the charcoal canister for physical damage such as cracks, broken or cracked fittings, damage from road debris, or rodent damage.
     
    Inspect all EVAP control devices (EVAP and purge control system monitors, controllers, and actuators) for physical damage such as cracks, broken or cracked fittings, damage from road debris, or rodent damage.
     
    Inspect all hoses and vacuum line connections for proper routing and placement.
     
    Inspect all electronic control devices for proper electrical connections.
     
    Inspect the condition of all fittings and seals for damage, drying, or wear.
     
    Inspect the condition of all hoses and vacuum lines for displacement, damage, or wear.
     

  2.  

If any physical defects are evident, verify the operation of any questionable components before replacement.

  1. Verify the operation of the EVAP system by performing any or all the following tests:

    Using a suitable scan tool, perform an actuator (active) test to verify the correct operation of EVAP control devices (EVAP and purge control system monitors, controllers, and actuators).
     
    Using a smoke machine, verify that the EVAP system does not exhibit any physical leaks.
     
    Using a suitable EVAP system pressure tester, verify that the EVAP system is properly sealed against positive and negative pressure.
     
    Using a suitable EVAP system pressure tester along with a suitable scan tool, monitor the EVAP pressure under positive and negative pressure conditions.
     

  2.  

Related Diagnostic Trouble Codes (DTC)

Specific to:

Chrysler Town & Country 2008-2009

Dodge Grand Caravan 2008-2009



Click image to see an enlarged view

Fig. Related Diagnostic Trouble Codes

 
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