Sometimes it's from the gas cap not sealing properly... a little Vaseline on the seal worked for me.

 

A new gas cap would be much cheaper that the diagnostic fee but evap codes are not always the gas cap. You can try a new gas cap or it would not be too difficult to follow the evap lines and look for a cracked hose which is the usual problem. Take off the engine cover and look at the evap lines and it just may be obvious. Gas vapor and engine heat deteriorate any rubber hose over time. Did they tell you the exact P code?

Edit: I was going to say to check the vacuum hose routing label on the underside of the hood but when I looked at our Dart, the VECI label is there but does not have a diagram of the vacuum hose routing. When did that change?

 

I agree. I had the same issue, but my husband is a mechanic. I got a new gas cap from the dealer ($36) as the after market ones don’t work as well. Still having the same issue after a drive cycle and clearing the code. He is going to replace the vacuum leak solenoid, Which will cost about $30 for him. I’ll keep you posted and let you know if that helps.

 

Got this from the online FSM for Wisconsin residents. Mods, feel free to add this to the Dart bible.

NOTE:
The Vehicle Emission Control Information (VECI) label(s) must be in place for the life of the vehicle. When replacing the component in which the VECI
label is adhered, a new VECI label must also be adhered to the new component.
All models have a VECI Label. Chrysler permanently attaches the label in the engine compartment. It cannot be removed without defacing information and destroying the label.
The label contains the vehicle's emission specifications and vacuum hose routings. All hoses must be connected and routed according to the label.

OPERATION
The ESIM (Evaporative System Integrity Monitor) 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.

1 - Intake Manifold

2 - Throttle Body

3 - Purge Solenoid

4 - Filter

5 - ESIM

6 - Vapor Canister

7 - Control Valve

8 - Fuel Tank

9 - Gas Cap

The ESIM assembly consists of a housing, a small weight and a large weight that serve as check valves, a diaphragm, a switch and a cover. There is one large weight and one small weight check valve in the ESIM assembly. A seal is attached at the end of each weighted check valve. The large weight check valve seals for pressure. The small weight check valve seals for vacuum. The weighted check valves are contained within the ESIM housing.

1 - ESIM Housing

2 - Diaphragm

3 - Switch

4 - Cover

5 - Small Check Valve

6 - Large Check Valve

The ESIM (Evaporative System Integrity Monitor), 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, two 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 .5 inches of water, the large check valve unseats and pressure vents to the fresh air filter.

Conversely, when the system cools and the resulting vacuum lifts the small check valve from its seat and allows fresh air to enter the system and relieve 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 test 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 diurnal ambient temperature cycling. When the vacuum in the system exceeds about 1” H20, the vacuum switch closes. The switch closure sends a signal to the GPEC1. 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.

1 - Large Check Valve

2 - Fresh Air Inlet

3 - Diagram

4 - Small Check Valve

5 - Vapor Canister

Conditions for running the intrusive test are:

After the vehicle is started, the engine coolant temperature must be within 10° C (50°F) of ambient to indicate a cold start.
The fuel level must be between 12% and 88%.
The engine must be in closed loop.
Manifold vacuum must be greater than a minimum specified value.
Ambient temperature must be between 4° C and 37° C (39° F and 98° F)and the elevation level must be below 8500 feet.

The test is accomplished by the GPEC1 activating the purge solenoid to create a vacuum in the evaporative system. The GPEC1 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 two 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 won’t be recorded until after the medium/large leak monitor has been run. This is accomplished by the GPEC1 activating the purge solenoid to create a vacuum in the evaporative system. The GPEC1 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 medium/large leak test runs and the ESIM switch doesn’t 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 doesn’t 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 two stage test and it runs only after the evaporative system passes the small leak test.

Stage one of the purge monitor is non-intrusive. GPEC1 monitors the purge vapor ratio. If the ratio is above a calibrated specification, the monitor passes. Stage two is an intrusive test and it runs only if stage one fails. During the stage two test, the GPEC 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 GPEC1 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 doesn’t open, the monitor fails. This is a two-trip MIL. The star scan tool can be used to force the ESIM switch stick closed monitor to run.

The GPEC1 also uses the ESIM to detect a loose or missing gas cap. The GPEC1 controller looks for a change in the fuel level (25% minimum) and then gas cap is loose or missing. If a medium/large leak is detected, a loose gas cap light illuminates and a pending one-trip fault code is set. On the GPEC1, this is a three-trip fault before the code matures.

1-Fresh Air Filter

2-Evaporative System Integrity Monitor (ESIM)

3-Evaporative Charcoal Canister

4-Fuel Tank Vent (Check Valve)

5-Control Valve

6-Inlet Check Valve

7-Fuel Tank Pressure Sensor

8-To Engine Purge Solenoid and Intake Manifold

9-Fuel Fill Tube

The evaporative emissions system is designed to control the release of fuel vapors into the atmosphere. The fuel tank check valve (4) and control valve (5) are used to reduce emissions due to the venting of vapor expansion within the fuel tank. When fuel evaporates from the fuel tank, vapors pass through a vent hose to the evaporative charcoal canister (3) where they are temporarily held. When the engine is running, the vapors are drawn into the intake manifold (8). In addition, fuel vapors produced during vehicle refueling are allowed to pass through the vent hose to the evaporative charcoal canister (3) for temporary storage (prior to being drawn into the intake manifold). The fuel tank check valve (4) and control valve (5) are non-serviceable components of the fuel tank assembly. The system is equipped with self-diagnosing capability using an Evaporative System Integrity Monitor (2) (Refer to 25 - Emissions Control/Evaporative Emissions/SWITCH, Evaporative Emissions System Monitor - Operation) .

The fuel tank pressure sensor (7) provides the PCM with information on vapor pressure inside the fuel tank. Excessive fuel tank pressure could cause fuel vapors to vent out the fuel filler cap or damage system components while insufficient fuel tank pressure (vacuum) caused by lack of fresh air entering the tank (1) to take the place of consumed fuel could lead to collapsed tank, lines or loss of fuel pressure.


The inlet check valve (6) prevents fuel from splashing back on the customer during vehicle refueling. This valve is also a non-serviceable component of the fuel tank assembly.

 

I just had a P0456 Very Small Leak for the evap emissions system on m Dart. I happened to have it at the dealer for replacement leather seat cover anyways so they looked at it. The light was on for a week and went off the day before I brought it in to them. They said everything looked fine and to just let them know if it comes back. They also noted that the computer logged 22 clean trips since the light came on, meaning that the light stayed on long past it going away. I did the usual gas cap check and that did nothing to help. Maybe it was just a bad seal on the cap for that refill or something. Either way it went away and has been fine since. I would keep an eye on it but not be too concerned just yet.

 

I had the EVAP warning happen on the Neon that I used to own, and in my case, it seems that it was cracked rubber hoses that was the problem. I have also learned from an Auto Radio Talk show that repeated filling of the gas tank beyond the first click of the pump nozzle can damage the EVAP System to be damaged. I've made sure to stop filling past the first click on my Dart, since I purchased it.

 

If it were me....before I would even consider spent the $140 diagnostic fee. I would try clearing the code first, and seeing if it returns. You should be able to to any of the big autoparts stores, Autozone/Advance/O'Reilly and borrow a code scanners to check codes. They will even help you, if you don't know how to use the scanner. But they won't clear the code. Usually they don't care if you do it yourself, they just won't do it. Then wait see if is comes back. If you don't want to go to the autoparts store, you should be able to disconnect the negative terminal on you battery for like 10-15min, and that should reset the computer.

EDIT: Also you can get a gas cap for probably less than $10 at any of the aforementioned autoparts stores or even Walmart. If you are even slightly concerned that it is the cause of your problem I would just replace it, also before wasting the money on the diagnostic fee. There is no need to have the Dealer replace your gas cap, when you basically do it every time you stop for gas.

 

Can anyone check their VECI label to see if there is a vacuum hose routing diagram on their label. All my other cars have something like this:
View attachment 68609

 

ESIM diagrams/information added to the bible.

 

Just wanted to throw in here that I hopped in our Dart to just move it in the driveway (make room for mowing), and noticed the engine liight on with this code. It's happened before, and I always first check the gas cap, especially if i wasn't the last one to fill it up. I slowly turned the cap CC, and it loosened without the springy resistance. Wife swears she always makes it click, and this isn't exactly the first car we've owned with this kind of gas cap, so I have no reason to doubt her. I think there may be a flaw in the cap spring that causes it to get loose sometimes between fill-ups. I gave it a few clicks, and reset the engine code, but it wouldn't surprise me to see it happen again.

 

The gas caps on these cars are strange. They will click clockwise but will release instantly when you turn them counter-clockwise. I've had this problem with one of my Darts.

 

It's easy to blame the gas cap but I don't think it's always the culprit. A similar design gas cap is on my '03 Dakota and most other newer Chryslers. It's never been the gas cap on the Dakota, always a cracked hose. I have two good spare gas caps which did not help.

 

I have to wait until 8/30 to get a loaner car. So I made the appointment for then.
It is Small Evaporation Leak, so I don't think I will hurt anything by putting it off? I'm hoping maybe it will maybe even disappear if I wait a bit longer, so this will give time to hold out and see just in case.

 

You must spread some Reputation around before giving it to @alpinegreenneon again.

 

So I have an update. I have an appointment for this upcoming Monday.
However, every time I start the car it does the warning beep and the check engine light is still showing, but now it says "Check Fuel Cap"
For weeks I have tried a normal shutting of the gas cap and as tight as possible. Should I bring it in for the appointment and have them take a look. It could be something like just buying a new gas cap, but I don't want to automatically do that if that is not the case. So maybe it is better if they briefly look at it first.


Now here is what I really want to know. Will they really charge me the $140 diagnostic fee if it says, "Check Fuel Cap". I understand if it was like earlier where it said small evaporation leak on the code and it was just the check engine light, but now this warning message is clearly displayed. What do you guys think?

 

call the service department and ask them about the $140 fee???

 

^ What he said. From my experience, I had a small evap emmisions leak in my Neon when I bought it. I replaced the cap and the code still came back. So I took it to the dealer. Even after telling them I already replaced the gas cap, they charged me the $90 diagnostic fee plus the cost of a new gas cap. (10 years ago) They didn't charge me the diagnostic fee the next day, when I took the car back, because like I originally told them it wasn't a bad gas cap.

EDIT: Also, I think you could rule out if the gas cap is causing the problem, just by stopping at the autoparts store and replacing the cap. Then clear the code. If it comes back, tell the dealer when you take it in what you did. Hopefully they will be competent and look for another cause. Rather than just assume it's the gas cap, replace it and send you on your way, only to have to come back again.

 

Here is my advice. Take it to a non dealer shop and ask for them to do a smoke test. If there is a leak they will find it performing this test. It's about 50 bucks. The dealer should charge for their services performed. 140 is a lot. Mechanics don't work for free, so I can't find fault in the dealer charging for their service.
If it has a problem then find out what the emissions warranty is for your state. This is an emission related problem and should be covered under this. Usually the emission warranty is for a longer duration then the regular warranty.
It's all a gamble in the end.
Pay for a new gas cap.
Pay for a smoke leak down test.
Possibly get banged for 140 by the dealer?
Possibly pay nothing from the dealer?
Take the route you feel most comfortable with. Personally, I would do the 50 route because it will tell me what is wrong with absolute certainty.

 

I have my Dart back and I found out it was a
P0456 EVAP SYSTEM Small Leak. ESIM Sticks.
DIAGNOSIS CHECK ENGINE LGIHT
REPLACED ESIM AND RECHECKED OK.

Part 1 Seal VAPO
Part 1 DETECTOR.

It cost about $208.98 total with parts & labor. the parts were only about $60 but the labor was 148. They do not also include the diagnostic fee if there is a problem that is more than $140 I found out. So if it was a new gas cap. They would charge $140-the cost of what the gas cap would be. Something along those lines. I guess it is for if someone brings a problem in and they can't find something for example or something minor.

Anyone else had this sensor replaced on their Dart? I also had to replace my right front parking bulb one that goes with the parking lights for $16. I got an oil change on top of that so altogether was $300 (It was $340 but I had a 10% off mopar coupon. I'm happy because I was thinking the cost for all that would be like $500 or $600. Could have been worse I guess.

 

Mine was a charcoal canister thing

Wanted 600 to fix I'm like nope

 

I had this code a while back as well... What I found is it was accompanied by a code that was "incorrect purge flow" as well.

What I did was bought a new purge solenoid, the one that sits right in front of the ecu. It was about $15 and was real easy to replace!

I found that inside of the original one that I had there was a decent amount of carbon buildup causing the purge valves plunger to not work correctly.

Sometimes, you can get away with cleaning it out with brake cleaner and letting it dry completely before hooking it back up... Other times, like my situation, not as lucky and you need a whole new purge valve.

 

Yes! About 2 months ago my CEL came on, took it to Auto Zone and got the code for small EVAP leak.
Light stayed on then was out when I went to work next morning. I had my husband take it in to check it out, and because the light wasn't ON, I got charged the 140 diagnostic. It stayed off until just 2 weeks ago, so I called the dealership again and they set me up an appointment, and said I won't have to pay the diagnosis charge again since it happened within 30 days. (They ran all the tests for it last time.) I asked if it was just a gascap issue, and they weren't sure...yeah..
So, I went and bought a gascap and sure enough, the light went out and has been out since. I cancelled the appointment. So I'm out 140 for a 13 dollar gascap. I was upset about paying for the diagnostic since I have an extended warranty, but apparently this is not covered. I call Chrysler corporate and complained about it plus the fact that this dealership (5*****) dealership insists on overinflating my 34psi tires to 39....I guess I've been lucky mostly with my Dart, I still love it, but future service will take me elsewhere. Sorry for the long post.

 

This CEL can also be triggered by fueling the car with the engine running. If you have the CEL, drive the car for a few days before you waste the $18 on a gas cap. and be sure you turn your car off to add gas.

 

yes my light just turned on and i have a small leak and i have a 2013 dodge dart 1.4L turbo i like the car just too much trouble so i need help with this question

 

See the diagnostic in the link below.
It can be lots of things.
No need to post the same thing over and over. Duplicate posts are deleted.

https://www.dodge-dart.org/threads/evap-info.46969/