P0302 on 2018-2025 Chrysler Pacifica: Cylinder 2 Misfire Causes and Fixes

What's Unique About the 2018-2025 Chrysler PACIFICA

The Chrysler Pacifica's 3.6L Pentastar V6 is a transverse (sideways) mounted engine. This design places cylinder 2 on the front-facing cylinder bank (Bank 2), making it very easy to access for diagnosis and repair. The cylinders on the front bank, from passenger side to driver's side, are 2, 4, and 6. This is a significant advantage compared to cylinders 1, 3, and 5 on the rear bank (Bank 1), which are located under the upper intake manifold and require several hours of labor to reach.

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
• Hesitation or stumbling during acceleration
• Noticeable loss of engine power
• Flashing or solid Check Engine Light
• Reduced fuel economy
• Engine ticking noise, which can point towards a rocker arm/lifter issue.

Most Likely Causes

1. Failed Ignition Coil 🔴 High Probability Ignition coils are a common wear item on many modern engines, including the 3.6L Pentastar. Heat cycles and vibration can cause the internal windings to fail over time.
   How to confirm: Swap the ignition coil from cylinder 2 with another easily accessible coil (e.g., cylinder 4). Clear the codes and drive the vehicle. If the code changes to P0304, the coil is faulty. This is a definitive diagnostic step.
   Typical fix: Replace the faulty ignition coil. Since cylinder 2 is on the front bank, this is a quick repair requiring only a 10mm socket to remove the hold-down bolt.
   Est. part cost: $30-$75
2. Worn or Fouled Spark Plug 🔴 High Probability Spark plugs have a finite service life, typically around 100,000 miles for the OEM plugs in this engine. TSB 09-013-20 REV. A was issued for 2020-2021 models due to a manufacturing defect causing internal cracks in the spark plugs, leading to misfires.
   How to confirm: Remove the spark plug from cylinder 2 and inspect it. Look for a cracked porcelain insulator, heavy carbon buildup, oil fouling, or excessive electrode wear. Compare its condition to a plug from a different cylinder.
   Typical fix: Replace the spark plug. It is best practice to replace all six spark plugs at the same time to ensure even performance. If the vehicle falls under TSB 09-013-20 REV. A, all six plugs must be replaced.
   Est. part cost: $10-$25 per plug
3. Faulty Fuel Injector 🟡 Medium Probability Fuel injectors can become clogged with deposits or fail electronically. While generally reliable on the Pentastar, failures can occur.
   How to confirm: A professional can perform a fuel injector balance test. A DIY method is to check the injector's resistance with a multimeter; a good injector should read around 12 ohms. You can also listen to the injector with a mechanic's stethoscope; it should make a consistent clicking sound. If code P0202 (Injector Circuit Malfunction) is present with P0302, the injector or its wiring is almost certainly the cause.
   Typical fix: Replace the faulty fuel injector. It's recommended to replace the O-rings on any injectors that are removed.
   Est. part cost: $45-$80 per injector.

Rare But Worth Checking

• Rocker Arm / Lifter Failure: The 3.6L Pentastar engine is known for potential issues with rocker arm bearings failing, which can cause the arm to become loose, leading to a ticking noise and a misfire. One owner of a 2017 Pacifica with P0302 and P105D traced the issue to a bad intake rocker arm. This is a more complex mechanical issue that often requires professional repair. The cost to replace all rocker arms can range from $1,000 to $2,000.
• Blown Head Gasket: While less common for a single-cylinder misfire, head gasket failures can occur on the 3.6L Pentastar. A leak between a coolant passage and cylinder 2 would cause a misfire. This would typically be accompanied by other symptoms like unexplained coolant loss, white smoke from the exhaust, or a milky appearance in the engine oil. A leakdown or compression test can confirm this.
• Wiring Issue / Poor Pin Contact: A technician working on a Jeep with the same engine and P0302 found the cause to be a poor pin connection in a large wiring harness connector near the passenger side valve cover. Wiggling the harness caused the misfire to come and go. This is a good check before assuming a major mechanical fault.

Diagnosis Steps

1. Read the code with an OBD-II scanner to confirm P0302 is present.
2. Check for a flashing Check Engine Light. If flashing, avoid driving to prevent catalytic converter damage.
3. Listen for a distinct ticking sound from the engine bay, which could indicate a rocker arm/lifter issue.
4. Locate cylinder 2. On the transverse 3.6L Pacifica engine, it is the front-most cylinder on the passenger side (Bank 2).
5. Inspect the wiring and connector for the cylinder 2 ignition coil and fuel injector for any visible damage or loose connections. Check the large harness connectors for proper seating.
6. Swap the ignition coil from cylinder 2 with the coil from cylinder 4 (the middle cylinder on the front bank). This requires a 10mm socket.
7. Clear the codes and run the engine until the Check Engine Light returns.
8. Re-scan for codes. If the code is now P0304, the ignition coil you moved is bad and needs replacement.
9. If the code remains P0302, the coil is likely good. Proceed to inspect the spark plug.
10. Remove the spark plug from cylinder 2. Check for wear, damage (especially cracked porcelain), or fouling. If it looks worn or damaged, replace it. It's recommended to replace all six at once, especially on 2020-2021 models covered by TSB 09-013-20 REV. A.
11. If the coil and plug are good, the issue may be with the fuel injector or a more serious mechanical problem. Listen to the injector with a stethoscope for a steady clicking. Check the injector resistance; it should be around 12 ohms. If other diagnostics fail, a compression or leak-down test is needed to check for internal engine problems like a bad rocker arm or head gasket issue.

Parts You'll Likely Need

• Ignition Coil (OEM #68223569AD) — This is one of the most frequent failure points for a single-cylinder misfire on the 3.6L Pentastar engine.
  Trusted brands: Mopar, NGK, Denso, Bosch
  OEM price range: $50-$90
  Aftermarket price range: $30-$75
• Spark Plug (OEM #SP225755AB (Mopar, replaces 68225755AA)) — A worn, fouled, or cracked spark plug is a primary cause of misfires. TSB 09-013-20 REV. A was issued for cracked spark plugs causing misfires on this engine.
  Trusted brands: Champion (OEM Iridium - RER8ZWYPB4), NGK (Iridium IX - LKR7DIX-11S), Denso (Iridium Long-Life - SXU22HCR11S)
  OEM price range: $15-$25
  Aftermarket price range: $10-$20

Related Codes That Often Appear With This One

• P0300 — If the misfire is intermittent or affects multiple cylinders, a P0300 (Random/Multiple Cylinder Misfire) may be stored alongside the specific cylinder code.
• P105D — This code relates to the intake valve being stuck in the high lift position. A Reddit user with a 2017 Pacifica reported this code appearing with P0302, which was ultimately traced to a bad intake rocker arm. Another owner fixed these codes by tightening a loose VVT solenoid bolt.
• P0202 — This indicates a fault in the cylinder 2 fuel injector circuit. If seen with P0302, it strongly points to the fuel injector or its wiring as the root cause.

Technical Service Bulletins (TSBs) & Recalls

• 09-011-25: Mentions P0302 as a possible Diagnostic Trouble Code related to MIL illumination for a wide range of models.
• 09-013-20 REV. A: Specifically addresses P0301-P0306 misfire codes on 2020-2021 Pacifica, Durango, Grand Cherokee and other models. It identifies a batch of faulty spark plugs with internal cracks and mandates the replacement of all six plugs.

Platform-Specific Known Issues

• TSB 09-013-20 REV. A was issued for 2020-2021 models for misfire codes (including P0302) caused by spark plugs with internal cracks due to a manufacturing issue. The fix is to replace all six spark plugs.
• The 3.6L Pentastar engine has a known potential for rocker arm/lifter failure, where the bearing on the rocker arm fails, causing a ticking noise and leading to a misfire. This is a more involved and expensive repair than standard ignition components.
• Some technicians report a higher-than-average rate of head gasket failure on this engine, which can cause misfires. A Jeep owner with a P0302 code discovered low compression requiring head repair/replacement.

Mechanic-Grade Diagnostic Values

• Fuel Injector Resistance — expected: Approximately 12.0 - 12.5 Ohms. Failure: A significantly higher reading (e.g., 63 Ohms) or an open circuit (infinite resistance) indicates a failed injector.
• Ignition Coil Primary Resistance — expected: 0.46 - 0.57 Ohms. Failure: A reading outside this range indicates a faulty coil.
• Ignition Coil Secondary Resistance — expected: 9.5 - 15.7 kOhms. Failure: A reading outside this range indicates a faulty coil.
• Fuel Pressure (at idle, vacuum line connected) — expected: ~31 psi (214 kPa). Failure: Pressure significantly lower than specification could indicate a weak fuel pump or clogged filter, contributing to a lean misfire.
• Fuel Pressure (at idle, vacuum line disconnected) — expected: ~39 psi (269 kPa). Failure: Pressure should rise when the vacuum line is disconnected; if it doesn't, the fuel pressure regulator may be faulty.

Scan Tool Commands That Help

• wiTECH (Chrysler Dealer Tool): OBD II Monitors -> 'Which cylinder is misfiring' — This function provides a live data view of misfire counts for each individual cylinder. It is extremely useful for confirming which cylinder is actively misfiring, especially when dealing with intermittent issues or a P0300 random misfire code, to isolate the fault to a specific cylinder.

Wiring & Ground Locations

• G201 — Behind the left side of the dashboard.. A poor ground at G201 can cause intermittent electrical issues for various components controlled by modules inside the cabin, potentially including the PCM or instrument cluster, which could theoretically manifest in erroneous codes or poor engine performance. While not a direct cause for a single cylinder misfire, checking major grounds is good practice for any electrical diagnosis.
• G102 / G103 — On the left side of the engine compartment.. These are primary engine and chassis grounds. A loose or corroded connection at these points can cause a wide range of issues, including weak spark or erratic sensor readings that could lead to a misfire code. Ensuring these are clean and tight is a fundamental step.

Real Owner Repair Stories

• Reddit user '01_Time' on r/ChryslerPacifica (2017 Pacifica Limited, 125k miles) — Rough idle after shifting into drive, MIL illuminated with codes P105D (Intake Valve Stuck In High Lift Position) and P0302 (Cylinder 2 Misfire).
  ❌ Tried (didn't work) Replaced the VVL solenoid, Replaced the spark plug for cylinder 2, Swapped the ignition coil from cylinder 2 to another cylinder
  ✅ What actually fixed it A professional mechanic diagnosed and replaced a bad intake rocker arm on cylinder 2. The mechanic noted this was a common failure on the 3.6L Pentastar engine.
• YouTube channel '150SCOOTER' (2018 Chrysler Pacifica) — Check Engine Light with codes P105D, P0300, and P0302.
  ❌ Tried (didn't work) Initial inspection focused on the ignition coil and spark plug for cylinder 2.
  ✅ What actually fixed it The owner discovered the hold-down bolt for the cylinder 2 VVT solenoid was completely loose. After tightening the bolt, all codes were cleared and the misfire was resolved. The owner suspects a dealer technician failed to tighten it during a previous service.
• YouTube channel 'Online Mechanic Tips' (2012 Minivan with 3.6L Pentastar V6) — P0302 misfire accompanied by a ticking noise.
  ❌ Tried (didn't work) Standard ignition system checks (plugs, coils).
  ✅ What actually fixed it The video explains that when a P0302 code is paired with a ticking noise, the root cause is often a valvetrain problem, such as a failed rocker arm or lifter, which is a known issue. The diagnosis requires a compression and/or leak-down test to confirm the mechanical fault before replacing ignition parts unnecessarily.

OEM Part Supersession History

• 68225755AA → SP225755AB — Standard part revision and update by the manufacturer.
• SP225755AA → SP225755AB — Standard part revision and update by the manufacturer.

Model Year Variations Within This Range

• 2020-2021: A specific batch of faulty spark plugs with internal cracks was identified in TSB 09-013-20 REV. A, causing misfires including P0302. Vehicles in this range with original plugs are highly susceptible. The fix is to replace all six plugs.
• 2021-2025: These models feature a facelift with revised styling and the Uconnect 5 infotainment system, but the 3.6L Pentastar engine and related components for a P0302 diagnosis remain mechanically identical to the 2018-2020 models.