P0456 on 2013-2016 Dodge DART: EVAP Small Leak Causes & Fixes

What's Unique About the 2013-2016 Dodge DART

The Dodge Dart, sharing its platform and components with other Chrysler products of the era, uses an Evaporative System Integrity Module (ESIM) to test for EVAP leaks. This component, a white plastic module attached to the charcoal canister, is a known high-failure item across the Chrysler/Dodge/Jeep lineup and is a very common cause of the P0456 code on the Dart. While many vehicles get this code from a simple loose gas cap, Dart owners frequently find the ESIM itself has cracked or failed internally, sometimes making a rattling sound when shaken. Additionally, some early model Darts with the 2.4L engine may have overly sensitive software that can trigger a false P0456, which can be corrected by a dealership PCM update per TSB 18-022-17 REV. A.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Check Engine Light is on
• A "Gas Cap Loose" or "Check Fuel Cap" message may appear on the dashboard, even with a new cap.
• A faint fuel smell (in rare cases).
• Difficulty starting immediately after refueling (if the purge valve is the culprit).
• Rough idle or poor engine performance if the purge valve is stuck open, creating a vacuum leak.

Most Likely Causes

1. Loose or Faulty Gas Cap 🔴 High Probability This is the most common cause for any vehicle, as the seal can degrade over time or the cap may not be tightened properly. Aftermarket caps are known to cause sealing issues.
   How to confirm: Ensure the gas cap is tightened until it clicks at least three times. Inspect the rubber O-ring seal on the cap for cracks, stiffness, or damage.
   Typical fix: Replace the gas cap. It's highly recommended to use an OEM Mopar part (like P/N 52030380AB) as aftermarket caps from brands like Duralast can sometimes fail to seal properly, leading to a repeat code.
   Est. part cost: $20-$35
2. Faulty Evaporative System Integrity Module (ESIM) 🔴 High Probability The ESIM is a documented high-failure-rate part on many Chrysler/Dodge vehicles, including the Dart. The plastic housing can crack, or the internal mechanism can fail, often causing a rattling sound when the old part is shaken.
   How to confirm: The ESIM is located on the charcoal canister, accessible by removing the right rear (passenger side) wheel and fender liner. A smoke test is the definitive way to confirm a leak from the ESIM housing. A rattling sound from the old unit is also a strong indicator of failure.
   Typical fix: Replace the ESIM (Mopar P/N 04861961AD). This involves removing the right rear wheel and fender liner (held by 8mm screws and plastic clips), disconnecting the electrical plug and hose, then twisting the old module counter-clockwise 🎬 Watch: Step-by-step guide to replacing the ESIM module. off the charcoal canister to remove it.
   Est. part cost: $30-$50
3. Faulty EVAP Purge Valve (Solenoid) 🟡 Medium Probability The purge valve can get stuck open or closed, disrupting flow and sometimes causing a leak code. This is a common failure point across many vehicles.
   How to confirm: The purge valve is located in the engine bay, on the back side of the engine. On the 2.4L engine, it's hidden behind the intake hose and a foam insulator. 🎬 See how to access and replace the purge valve. It is a normally closed valve. You can test it by removing it and trying to blow through it; if air passes, it is stuck open and has failed. A professional can also command it open and closed with a scan tool.
   Typical fix: Replace the purge valve solenoid. The Mopar part number is 4627182AA for all Dart engines.
   Est. part cost: $40-$70
4. Cracked or Disconnected EVAP Hoses ⚪ Low Probability Rubber and plastic hoses can become brittle and crack over time due to heat and age, especially at connection points.
   How to confirm: Visually inspect all accessible EVAP lines between the engine bay, charcoal canister, and fuel tank for cracks, chafing, or loose connections. A smoke test is the most effective way to find a hard-to-see leak.
   Typical fix: Replace the damaged section of hose. In some cases, a cracked rigid plastic line can be temporarily repaired with a section of rubber fuel hose.
   Est. part cost: $10-$40

Rare But Worth Checking

• Warped or Damaged Fuel Filler Neck: A repair shop noted that on Darts, the fuel filler neck itself can become distorted or rusty, preventing the gas cap from sealing properly, even if the cap is new. This requires a smoke test to confirm the leak is at the cap's sealing surface. Some owners have had success sanding the filler neck surface smooth.
• Cracked Charcoal Canister: While less common than the ESIM failing, the body of the charcoal canister itself can develop a crack, causing a leak.
• Sensitive PCM Software: TSB 18-022-17 REV. A and 18-023-16 indicate that some 2013-2015 Darts with the 2.4L engine can set a false P0456 due to overly sensitive leak detection logic. A dealership can perform a PCM software update to correct this.

Diagnosis Steps

1. Check the gas cap. Remove it, inspect the seal for damage, and reinstall it, ensuring it clicks several times. Using an OEM Mopar cap is strongly recommended. Clear the code and drive for a few days to see if it returns.
2. If the code returns, perform a visual inspection. Check the EVAP purge valve and its hoses in the engine bay (located on the rear of the engine).
3. To definitively find the leak, a professional smoke test is recommended. A machine injects harmless, visible smoke into the EVAP system via the service port. The leak will be wherever smoke escapes.
🎬 Watch: How to perform a professional EVAP smoke test.
4. Based on owner reports, pay close attention to the ESIM on the charcoal canister during the smoke test. This is a very common failure point. The ESIM is located behind the passenger-side rear wheel well liner.
5. Also check the fuel filler neck sealing surface for any signs of rust, warping, or damage that could prevent a good seal with the cap.
6. If no physical leak is found, especially on a 2.4L model, consult a dealer about TSB 18-022-17 REV. A to see if a PCM software update is applicable.

Parts You'll Likely Need

• Gas Cap (OEM #52030380AB) — This is the simplest and most common starting point for a P0456 code. The seal wears out over time, and aftermarket caps are often problematic.
  Trusted brands: Mopar (recommended), Gates, Stant
  OEM price range: $25-$35
  Aftermarket price range: $15-$25
• Evaporative System Integrity Module (ESIM) (OEM #04861961AD) — This is a very common failure point on the Dodge Dart that causes a small EVAP leak. The plastic housing is prone to cracking or internal failure. This part supersedes 4861961AA, 4861961AB, 4861961AC, and 4891686AA.
  Trusted brands: Mopar, Dorman, Standard Motor Products
  OEM price range: $40-$60
  Aftermarket price range: $25-$45
• Canister Purge Valve / Solenoid (OEM #4627182AA) — Can get stuck open, causing a constant vacuum leak within the EVAP system, triggering the code. This part fits all Dart engines (1.4L, 2.0L, 2.4L).
  Trusted brands: Mopar, Duralast, Bosch
  OEM price range: $50-$70
  Aftermarket price range: $30-$60

Related Codes That Often Appear With This One

• P0457 — This code specifically means "EVAP System Leak Detected (Fuel Cap Loose/Off)". It often appears alongside P0456 if the system suspects the gas cap is the primary issue, or if the ESIM has failed.
• P0441 — This code indicates "EVAP System Incorrect Purge Flow". It can be triggered if the purge valve is stuck open or closed, which can also contribute to a P0456 leak code. TSB 18-022-17 REV. A addresses both codes with a software update.

Technical Service Bulletins (TSBs) & Recalls

• 18-022-17 REV. A - For 2013-2015 Darts with the 2.4L engine, this TSB involves a PCM software update to address several potential DTCs, including P0456 and P0441, which may be triggered

Platform-Specific Known Issues

• The Evaporative System Integrity Module (ESIM) attached to the charcoal canister is a documented high-failure part, often cracking or failing internally and causing a P0456 code. Many owners fix the code by replacing this part after a new gas cap fails to solve it.
• A repair facility has noted that the fuel filler neck can become distorted, leading to an improper gas cap seal and a persistent P0456 code even with a new cap.
• The PCM software on 2013-2015 2.4L models may be too sensitive, triggering false P0456 codes. TSB 18-022-17 REV. A addresses this with an update.

Mechanic-Grade Diagnostic Values

• EVAP Purge Valve Solenoid Resistance — expected: Approximately 14 to 22 ohms.. Failure: A reading of infinite resistance (open circuit) or zero resistance (short circuit) indicates a failed solenoid coil.
• Fuel Tank Pressure (FTP) Sensor Voltage — expected: The sensor is a 3-wire design: one pin should have a 5-volt reference from the PCM, one should have a good ground, and the third is the signal wire.. Failure: Missing 5V reference or ground indicates a wiring issue. The signal voltage should change when pressure is applied (e.g., with a hand vacuum pump), if it's stuck at a specific voltage, the sensor has failed.
• EVAP System Pressure (Live Scan Tool Data) — expected: A normal reading varies, but one owner reported seeing 15,839 Pa while troubleshooting a leak.. Failure: The key is to watch this value during a commanded EVAP test; if the system cannot hold a vacuum/pressure as commanded by the scan tool, it confirms a leak is present.

Scan Tool Commands That Help

• wiTECH (Chrysler/Dodge/Jeep Dealer Tool): Small Leak Verification Test (SLVT) — This is a mandatory first step in dealer diagnosis for P0456. It verifies a leak is currently present before replacing parts and is also used to confirm the repair is successful afterward. A standard road test will not confirm the fix, as the code requires multiple specific drive cycles to set.

Wiring & Ground Locations

• Main Engine/Chassis Ground — A key ground path runs from the battery negative terminal to a stud on the driver's side frame rail (behind the splash guard), and then a separate wire runs from that stud to the transmission case.. Corrosion at this frame stud is a known issue on Darts and can cause numerous electrical problems, including erratic sensor readings. A poor ground can affect the accuracy of the Fuel Tank Pressure sensor and other EVAP components, potentially leading to false codes.
• G109 — Located on the left (driver's) side of the engine compartment on the wheel well.. This is a major ground point for various components in the engine bay. A wiring diagram for the 1.4L engine shows the ESIM switch is grounded through the PCM, which relies on clean main engine grounds like this one.
• ESIM Connector Pinout — On the ESIM module, attached to the charcoal canister behind the passenger rear wheel well liner.. The ESIM has a 3-pin connector. According to wiring diagrams, these pins are for a 5-volt supply, a ground, and the switch signal back to the Powertrain Control Module (PCM). Testing for proper voltage and ground at this connector is crucial before condemning the ESIM.

Real Owner Repair Stories

• Reddit user u/CK46111 (2015 Dodge Dart SE 2.0L) — Recurring P0456 (Small Leak), P0457 (Fuel Cap Loose), and P0441 (Incorrect Purge Flow).
  ❌ Tried (didn't work) Replaced gas cap, Replaced canister purge valve, Performed a smoke test which showed no visible leaks
  ✅ What actually fixed it Replacing the Evaporative System Integrity Module (ESIM). The user noted it was a '$40 part installed in 10 min' and the check engine light turned off.
• YouTube channel WongAutoFix (2015 Dodge Dart) — P0456 code.
  ✅ What actually fixed it The user identified the ESIM as the problem. They demonstrated that the old, failed unit made a rattling sound when shaken, while the new replacement part did not, indicating an internal failure. Replacing the ESIM resolved the code.

"I Checked Everything" — The Actual Cause

• In one documented case, a 2015 Dart owner had a persistent P0456 code and performed a smoke test which revealed no leaks. After replacing the gas cap and purge valve with no success, the actual cause was determined to be an internally failed ESIM module, which was not leaking externally but was electronically faulty.
• An NHTSA document warns technicians that when performing a smoke test for P0455/P0456, using the standard test adapter in place of the vehicle's gas cap can mask a real leak. The larger O-ring on the test tool may seal a warped or rusty fuel filler neck that the actual gas cap cannot, leading to a false 'no leak found' result.

OEM Part Supersession History

• 4861961AA, 4861961AB, 4861961AC, 4891686AA → 04861961AD — Standard part revision and consolidation by the manufacturer for the ESIM.

Model Year Variations Within This Range

• 2013-2014: Owner forums and reviews suggest that earlier model year Darts, particularly 2013-2014, were more prone to a variety of electrical and engine issues compared to the final 2016 models. While the P0456 causes are largely the same, reliability of related components may be lower on early-production vehicles.