P0302 on 2014-2018 Ford Fusion: Cylinder 2 Misfire Causes and Fixes

What's Unique About the 2014-2018 Ford FUSION

While misfires are common on all vehicles, the 2014-2018 Ford Fusion with the 1.5L and 2.0L EcoBoost engines has a well-documented, serious issue that can cause this code. A design flaw in the open-deck engine block features a thin wall and narrow coolant passages between the cylinders. This area can crack, allowing coolant to leak directly into the combustion chamber, which fouls the spark plug and causes a misfire. This makes a P0302 code on these specific engines potentially much more severe than a simple ignition component failure, as it is a primary symptom of a cracked engine block requiring a complete long block replacement per Ford's own Technical Service Bulletins.

Diagnostic Flowchart

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

Symptoms You May Notice

• Rough or shaky idle, especially on a cold start
• Hesitation or stumbling during acceleration
• Noticeable loss of engine power
• Flashing or solid Check Engine Light
• Smell of unburned gasoline from the exhaust
• Decreased fuel economy
• For EcoBoost engines: Steadily dropping coolant level without any visible external leaks
• For EcoBoost engines: White, sweet-smelling smoke from the exhaust, particularly noticeable on a cold start

Most Likely Causes

1. Faulty Ignition Coil 🔴 High Probability Coil-on-plug systems are common failure points due to constant exposure to heat and vibration. Many owners report successfully fixing a P0302 by replacing the coil. [ODI #11258356, ODI #11355165] It is a logical first diagnostic step.
   How to confirm: Swap the ignition coil from cylinder 2 with another cylinder (e.g., cylinder 3). Clear the codes and drive the vehicle. If the code changes to P0303, the ignition coil is faulty. This is a widely recommended DIY diagnostic step. 🎬 Watch: A helpful guide on diagnosing and fixing the P0302 code.
   Typical fix: Replace the faulty ignition coil. It is recommended to use a quality OEM replacement like Motorcraft (part DG562) to avoid resistance issues with aftermarket parts.
   Est. part cost: $40-$75
2. Worn or Fouled Spark Plug 🔴 High Probability Spark plugs are a regular maintenance item. A worn electrode, incorrect gap, or fouling from carbon/oil can prevent a proper spark. On EcoBoost engines, coolant intrusion is a very common cause of a fouled plug in a specific cylinder. One owner on a forum noted the ground electrode on the plugs for cylinders 2 and 3 was completely gone.
   How to confirm: Remove the spark plug from cylinder 2 and inspect it. Look for wear, damage, or deposits. Black soot indicates a rich condition, oily residue points to a valve cover gasket leak, and a white/greenish tint or an unusually clean, 'steam-cleaned' appearance suggests coolant is entering the cylinder.
   Typical fix: Replace the spark plug. It is best practice to replace all spark plugs at the same time with the specified OEM part, such as Motorcraft SP-530.
   Est. part cost: $8-$25 per plug
3. Engine Coolant Intrusion (1.5L & 2.0L EcoBoost) 🟡 Medium Probability A known defect in the open-deck engine block design can cause cracks between cylinders, allowing coolant into the combustion chamber. This is addressed in Ford TSB 19-2346 (for 2.0L) and TSB 20-2100 (for 1.5L). Ford also initiated Customer Satisfaction Program 21N12 🎬 See how to diagnose 1.5L EcoBoost misfires and coolant loss. for the 1.5L engine, extending the warranty for this specific issue to 7 years or 84,000 miles.
   How to confirm: Check for a steadily dropping coolant level with no external leaks. Look for white exhaust smoke. A mechanic can perform a cooling system pressure test, test for combustion gases in the coolant, or use a borescope to look for coolant inside the cylinder. A shiny, steam-cleaned piston top is a tell-tale sign.
   Typical fix: Per Ford's TSBs, the only permanent fix is to replace the engine with a redesigned long block (for 2.0L) or short block (for 1.5L) assembly. Using stop-leak products is not recommended as it can clog the radiator and heater core.
   Est. part cost: $4000-$8000 for a new long block
4. Clogged or Faulty Fuel Injector ⚪ Low Probability
   How to confirm: After ruling out spark-related issues, a fuel injector is the next likely culprit. A mechanic can perform a fuel injector balance test. Swapping the injector with another cylinder to see if the misfire code follows is also possible but is more labor-intensive than swapping a coil.
   Typical fix: Clean or replace the faulty fuel injector.
   Est. part cost: $50-$120

Rare But Worth Checking

• Damaged Charge Air Cooler (CAC): According to TSB 17-0028, an intake manifold bolt can back out and damage the Charge Air Cooler, leading to misfires, low coolant, and white smoke. This is a specific mechanical failure to be aware of if other symptoms match. [TSB #17-0028]
• Loss of Engine Compression: Internal engine damage such as a burnt valve, damaged piston, or head gasket failure can cause a loss of compression, resulting in a misfire. This is less common than ignition or fuel issues but should be checked with a compression test if the basics don't solve the problem. On EcoBoost engines, this is often the result of the coolant intrusion issue.
• Leaking Valve Cover Gasket: A less common cause for a misfire is oil leaking from the valve cover gasket's spark plug tube seals into the spark plug well. This can saturate the ignition coil boot and short out the spark. An owner on a Reddit forum experienced this issue.

Diagnosis Steps

1. Read the trouble codes with an OBD-II scanner. Note if P0302 is alone or accompanied by codes like P0300, P0316, or overheat codes.
2. (For EcoBoost Engines) Immediately check the coolant reservoir. A low level with no visible external leaks is a major red flag for internal coolant intrusion.
3. Locate cylinder 2. On Ford inline-four engines, cylinders are numbered 1-2-3-4 from the front (passenger side, where belts are) to the back (driver side, transmission).
4. Swap the ignition coil from cylinder 2 with the coil from cylinder 3. Clear the codes, run the engine, and see if the code changes to P0303. If it does, the coil is bad. This is the cheapest and easiest first step.
5. If the code remains P0302, remove and inspect the spark plug from cylinder 2. Look for excessive wear, oil fouling (from a valve cover leak), or a 'steam-cleaned' appearance, which indicates coolant. Replace if necessary.
6. If ignition components are good, the next step is to check the fuel injector. This may require professional diagnosis.
7. If symptoms of coolant intrusion are present (low coolant, white smoke), insist on a proper diagnosis. This includes a cooling system pressure test and a borescope inspection of cylinder 2. Look for liquid coolant or an unusually clean, shiny piston crown. Refer the service provider to TSB 19-2346 (2.0L) or TSB 20-2100 (1.5L).

Parts You'll Likely Need

• Ignition Coil (OEM #DG562) — This is one of the most common failure items for a single-cylinder misfire. An owner complaint confirms this was a first-step replacement. [ODI #11355165] DIY videos confirm the part number and ease of replacement.
  Trusted brands: Motorcraft, NGK, Bosch, Denso
  OEM price range: $60-$80
  Aftermarket price range: $35-$60
• Iridium Spark Plug (OEM #SP-530) — Spark plugs are a routine maintenance part and a frequent cause of misfires. Owner complaints show this is a common part to replace. [ODI #11355165] They are also the first part to be fouled by coolant intrusion.
  Trusted brands: Motorcraft, NGK, Denso
  OEM price range: $10-$15
  Aftermarket price range: $8-$12
• Engine Short Block (1.5L) or Long Block (2.0L) (OEM #DS7Z6009J (1.5L Short Block)) — For the EcoBoost engines, this is the ultimate fix for the coolant intrusion issue. The replacement blocks feature a revised design to prevent the failure from recurring.
  Trusted brands: Ford (Motorcraft)
  OEM price range: $4000-$8000
  Aftermarket price range: $3000-$6000

Related Codes That Often Appear With This One

• P0300 — This is a 'Random Misfire' code. It can appear alongside P0302 if the misfire is intermittent or starting to affect other cylinders, which is common with the coolant intrusion issue.
• P0316 — Indicates 'Misfire Detected on Startup (First 1000 Revolutions)'. It often accompanies specific cylinder misfire codes and is a hallmark of the coolant intrusion problem, as coolant pools in the cylinder overnight and causes a misfire on a cold start. [TSB #SSM 47204, TSB 19-2346, 6, 17]
• P0217, P1299 — These codes indicate an engine overheat condition. They can be triggered along with misfire codes when the cause is a significant coolant leak into the cylinder, leading to a loss of coolant in the system. [TSB #17-0028, TSB 19-2346, 11]

Technical Service Bulletins (TSBs) & Recalls

• SSM 47204: Notes that 2015-2018 Fusions with the 2.0L EcoBoost may run rough with P030x codes due to coolant intrusion from engine block corrosion.
• TSB 17-0028: Links P030x codes to a backed-out intake manifold bolt damaging the Charge Air Cooler, causing low coolant and white smoke.
• TSB 19-2346: Supersedes earlier bulletins for the 2.0L EcoBoost, confirming coolant intrusion as the cause for misfires and stating the official repair is a long block engine replacement.

Platform-Specific Known Issues

• 2.0L EcoBoost Coolant Intrusion: TSB 19-2346 (which supersedes SSM 47204 and TSB 19-2208) describes an issue where coolant can intrude into the cylinders due to a crack in the engine block's open-deck design. Symptoms include a rough running condition, white exhaust smoke, and low coolant. The only prescribed fix is a complete long block replacement.
• 1.5L EcoBoost Coolant Intrusion: TSB 20-2100 (which supersedes TSB 19-2375) describes the identical coolant intrusion issue for the 1.5L engine. The fix is a new short block assembly. Ford also issued Customer Satisfaction Program 21N12 to provide a one-time, no-cost repair for this issue for up to 7 years or 84,000 miles.

Mechanic-Grade Diagnostic Values

• Ignition Coil Primary Winding Resistance — expected: 0.49 - 0.57 Ohms. Failure: A reading outside this range indicates a faulty coil.
• Ignition Coil Secondary Winding Resistance — expected: 9.5 - 11.1 kOhms. Failure: A reading outside this range indicates a faulty coil.
• Fuel Injector Resistance (Direct Injection) — expected: Approximately 12 - 15 Ohms. Failure: A significantly higher reading (e.g., 50+ Ohms) or an open circuit indicates a failed injector.

Hidden / Shadow Codes Worth Checking

• Mode 6 ($06) Misfire Data: The PCM logs misfire counts for each cylinder in Mode 6 data, often before the misfire is severe enough to trigger a Check Engine Light. This allows a technician to see which cylinder is misfiring intermittently. (see via A professional scan tool with Mode 6 capabilities is required. The technician can view the misfire count for Test ID $A2 through $AB, with each component ID corresponding to a cylinder.)

Scan Tool Commands That Help

• Ford IDS, Forscan, high-end Snap-on/Autel scanners: Power Balance Test — This is a critical bidirectional test used to pinpoint a weak cylinder when a misfire is suspected but the cause is unclear. The tool deactivates one cylinder at a time (by cutting its fuel injector) and graphs the resulting drop in RPM. A cylinder that causes little or no RPM drop when disabled is not contributing power and is the source of the misfire.

Wiring & Ground Locations

• G104 — Right side of the engine compartment.. Provides a ground path for various engine components. A corroded or loose G104 can cause intermittent electrical issues, including weak spark or erratic sensor readings that could lead to a misfire code.
• G105 — Left front of the engine compartment, behind the cooling fan relays.. Grounds several components in the front of the engine bay. Poor grounding here can introduce electrical noise and potentially affect PCM calculations or ignition performance.
• PCM Connector — Typically located in the engine bay, often near the firewall or battery.. The wiring for the ignition coil and fuel injector for cylinder 2 runs to this connector. A visual inspection for corrosion, backed-out pins, or harness damage near the connector is a valid diagnostic step if electrical issues are suspected.

Real Owner Repair Stories

• Reddit user in /r/fordfusion (2013 Fusion Titanium 2.0L EcoBoost) — Random misfire under acceleration (P0302), flashing check engine light that went away.
  ❌ Tried (didn't work) Initial diagnosis was unclear.
  ✅ What actually fixed it The user pulled all plugs and coils. The ground electrodes on the spark plugs for cylinders 2 and 3 were completely missing, and oil was caked around them. The final diagnosis was a leaking valve cover gasket which allowed oil into the spark plug tubes, causing the issue. The fix was a new valve cover gasket and new plugs/coils.
• YouTube Commenter (Not specified, general P0302 case) — P0302, very bad rough idle, engine shaking and stalling.
  ❌ Tried (didn't work) Replacing ignition coils and spark plugs had no effect.
  ✅ What actually fixed it The owner suspected a clogged fuel injector and added Redline fuel injection cleaner to the fuel tank. After running the car for a while, the rough idle and misfire were resolved, and the code cleared.
• Reddit user in /r/fordfusion (2016 Fusion Titanium 2.0L EcoBoost, 95k miles) — P0302 misfire, low coolant level.
  ❌ Tried (didn't work) Replaced spark plugs, which only solved the issue for about a week., Swapped ignition coil with a known good one, but the misfire on cylinder 2 remained.
  ✅ What actually fixed it The combination of a persistent P0302 on cylinder 2 and a low coolant level strongly indicated the known coolant intrusion issue. The user was advised to research the TSBs related to this problem, as the likely fix is a new engine.

"I Checked Everything" — The Actual Cause

• A common misdiagnosis pattern for the 1.5L and 2.0L EcoBoost engines involves a technician performing a smoke test to check for vacuum leaks. The test will come back clean, showing no leaks in the intake system. However, the root cause of the P0302 is often an internal coolant leak directly into the cylinder from a crack in the engine block's deck face. This type of failure is completely invisible to a smoke test and requires different diagnostic methods, such as a cooling system pressure test or a borescope inspection, to identify.

When the Usual Fixes Don't Work

• While the most severe cause of P0302 on an EcoBoost Fusion is coolant intrusion, it is not always the answer. Multiple owner accounts confirm that after replacing standard ignition components without success, the final fix was a less common issue. In one case, a thoroughly clogged fuel injector was the culprit, which was resolved with a high-quality fuel system cleaner after new plugs and coils failed to fix the problem. In another verified case, the root cause was oil leaking into the spark plug tube from a faulty valve cover gasket, which shorted out the new plug and coil. These instances prove that even on a platform with a notorious major engine flaw, technicians should not skip fundamental diagnostics for fuel delivery and oil leaks before concluding the engine needs replacement.

OEM Part Supersession History

• N/A - Original 'slotted' engine block → Revised block with 'cross-drilled' coolant passages (Example 2.0L Long Block: J2GZ6006E) — The original open-deck block design had a thin slot for coolant between cylinders, providing insufficient sealing surface for the head gasket under boost and heat. This led to head gasket failure and coolant intrusion. The revised design removes the slot and uses drilled holes, creating a stronger deck and preventing the leak.
  Heads up: When replacing an engine due to coolant intrusion, it is critical to ensure the replacement is the updated 'cross-drilled' design to permanently solve the problem. Installing an older-style block will lead to a repeat failure.
• DS7Z-6009-G → DS7Z-6009-J — This is the part number for the 1.5L EcoBoost short block assembly. The supersession represents a revised version of the block intended to correct the coolant intrusion flaw.

Model Year Variations Within This Range

• 2014 - Early 2019: 1.5L and 2.0L EcoBoost engines produced before mid-2019 feature the original engine block design with a slot between the cylinders. These engines are highly susceptible to the coolant intrusion failure that commonly causes a P0302 code.
• Late 2019 - 2020: Engines manufactured from mid-2019 for the 2020 model year feature a revised, more robust block design where the slot is replaced by drilled coolant passages. This design corrects the flaw and is not prone to the same coolant intrusion issue.