P2305 on 2015-2016 Dodge Caravan: Ignition Coil Circuit Fault Causes and Fixes

What's Unique About the 2015-2016 Dodge CARAVAN

The 3.6L Pentastar V6 used in the 2015-2016 Grand Caravan is a very common engine across the Chrysler, Dodge, and Jeep lineup. While generally reliable, ignition coil failures are a frequent maintenance item. The code P2305 is specifically referenced in manufacturer technical service bulletin #18-069-16, indicating it's a known issue. For a specific build range of 2015 models (July 27, 2015, to September 11, 2015), this TSB actually recommends replacing the PCM as the primary fix due to a manufacturing defect. Accessing the rear bank of cylinders (including #2) requires removing the upper intake manifold, adding labor time and complexity to the repair.

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 or flashing
• Engine misfire, which feels like shaking, stumbling, or a rough idle
• Hesitation or lack of power during acceleration
• Reduced fuel economy
• Engine runs rough

Most Likely Causes

1. Faulty Ignition Coil #2 🔴 High Probability Ignition coils are a common wear item on the Pentastar engine. This specific family of codes is also documented by the manufacturer for this vehicle in TSB #18-069-16.
   How to confirm: The easiest way to confirm is to swap the ignition coil from cylinder #2 with another cylinder (e.g., cylinder #4 on the front bank). Clear the codes and drive. If the code changes to P2311 (Ignition Coil #4 Secondary Circuit), the coil is bad.
   Typical fix: Replace the faulty ignition coil. Since cylinder #2 is on the rear bank, the upper intake manifold must be removed for access.
   Est. part cost: $30 - $120
2. Worn or Fouled Spark Plug in Cylinder #2 🟡 Medium Probability Spark plugs are a maintenance item with a finite lifespan. An excessively worn electrode increases the voltage required to create a spark, which can strain the coil and be detected by the PCM as a secondary circuit fault.
   How to confirm: After ruling out the ignition coil, remove and inspect the spark plug from cylinder #2. Look for a worn electrode, carbon fouling, oil, or cracks in the ceramic insulator. This requires removing the upper intake manifold.
   Typical fix: Replace the spark plug. It is highly recommended to replace all six spark plugs at the same time, especially if the vehicle is near its 100,000-mile service interval.
   Est. part cost: $8 - $25 per plug
3. Damaged Wiring or Poor Connection ⚪ Low Probability Rodents can chew on wiring harnesses, and connectors can become loose or corroded over time. Some owners of platform-mates have reported backed-out pins in the coil connector or even the main PCM connector causing this issue.
   How to confirm: Visually inspect the wiring harness and connector for the cylinder #2 ignition coil. Check for frayed wires, corrosion on the pins, or a loose-fitting connector. Ensure the red locking tab on the connector is fully engaged. Use a multimeter to check for proper voltage and ground at the connector.
   Typical fix: Repair the damaged section of the wiring harness or clean/replace the connector.
   Est. part cost: $10 - $50 for repair materials

Rare But Worth Checking

• Faulty Powertrain Control Module (PCM): This is normally the least likely cause, but TSB #18-069-16 REV A specifically calls for PCM replacement on some 2015 models built between July 27, 2015 and September 11, 2015. The bulletin suggests an improperly coated vent on the PCM could lead to internal failure. For vehicles outside this build date range, this should only be considered after all other possibilities (coil, plug, wiring) have been exhaustively ruled out. Some forum users have noted that using certain aftermarket coils can potentially damage the PCM driver for that cylinder.

Diagnosis Steps

1. Read the trouble codes with an OBD-II scanner and note any other codes present, like P0302.
2. Check the vehicle's build date on the driver's door jamb sticker. If it falls between July 27, 2015, and September 11, 2015, consult TSB #18-069-16 REV A, as a PCM replacement may be the required fix.
3. Visually inspect the wiring and connector for the cylinder #2 ignition coil. Look for any obvious signs of damage, corrosion, or loose connections. Ensure the red locking tab is secure.
4. To quickly test the coil, swap the ignition coil from cylinder #2 (rear bank, middle cylinder) with the coil from cylinder #4 (front bank, middle cylinder). This is the easiest swap as it doesn't require removing the intake manifold.
5. Clear the codes and start the engine. Let it run for a few minutes.
6. Re-scan for codes. If the code has changed to P2311 (Ignition Coil #4 Secondary Circuit), the ignition coil you moved is faulty and needs to be replaced.
7. If code P2305 returns, the problem is not the coil. The next step is to inspect the spark plug. This will require removing the upper intake manifold to access cylinder #2.
8. Once the intake is removed, replace the spark plug for cylinder #2. It's best practice to replace all three rear plugs (or all six) at this time.
9. If the plug and coil are confirmed good, the issue lies in the wiring harness or the PCM. Use a multimeter to test the coil control circuit for continuity, shorts to ground, and proper signal from the PCM.
10. If wiring tests good and the vehicle does not fall under the TSB, the PCM is the last remaining, though rare, possibility.

Parts You'll Likely Need

• Ignition Coil (OEM #5149168AI) — This is the most common cause of code P2305. The coil is responsible for generating the high voltage for the spark plug, and internal failure is frequent.
  Trusted brands: Mopar, NGK, Denso, Delphi
  OEM price range: $80-$120
  Aftermarket price range: $30-$70
• Spark Plug (OEM #SP149125AF) — A worn or fouled spark plug can cause this code by increasing the electrical resistance in the secondary circuit. It's often replaced along with the coil. The OEM plug is typically an NGK Iridium plug.
  Trusted brands: NGK (OEM supplier), Champion, Denso
  OEM price range: $15-$25
  Aftermarket price range: $8-$18
• Upper Intake Manifold Gasket Set — This is required to access the rear bank of cylinders (1, 2, 3) for coil or spark plug replacement. The gaskets must be replaced anytime the manifold is removed. 🎬 Watch: Quick guide to changing spark plugs on this engine.
  Trusted brands: Mopar, Fel-Pro (MS 97204 is a common part number), Mahle
  OEM price range: $25-$40
  Aftermarket price range: $15-$30

Related Codes That Often Appear With This One

• P0302 — P0302 means 'Cylinder 2 Misfire Detected'. P2305 is a more specific code that identifies the likely cause of the misfire is the ignition coil #2 secondary circuit. They almost always appear together.
🎬 See a confirmed fix for codes P0302 and P2305.
• P0300 — P0300 means 'Random/Multiple Cylinder Misfire Detected'. If the underlying issue (like a failing PCM as noted in TSB #18-069-16) starts to affect other cylinders, you may see this code alongside P2305.

Technical Service Bulletins (TSBs) & Recalls

• 18-069-16 REV A: Addresses multiple ignition coil secondary circuit codes (P23xx) and misfire codes (P030x). For vehicles built between July 27, 2015, and September 11, 2015, the bulletin advises replacing the Powertrain Control Module (PCM) due to a manufacturing defect that allows for inadequate environmental protection.

Platform-Specific Known Issues

• Accessing the rear bank of cylinders (where #2 is located) requires removing the upper intake manifold, which adds complexity and time to the repair compared to the front bank. This involves disconnecting several hoses, electrical connectors, and brackets.
• Some owners on forums have reported that these engines can be sensitive to aftermarket ignition coils, sometimes leading to persistent issues or premature failure. Using an OEM Mopar or a high-quality OEM-supplier coil like NGK is often recommended if problems continue after replacement.
• TSB #18-069-16 REV A is a critical consideration for 2015 models built between July and September. A faulty PCM can cause this code, and replacing only the coil will not fix the issue.

Mechanic-Grade Diagnostic Values

• Ignition Coil Connector Pin 2 (Power Feed) Voltage — expected: ~12V (Battery Voltage) with key on, engine off.. Failure: 0V or significantly low voltage indicates a problem with the ASD (Auto Shutdown) relay or the power feed wire.
• Ignition Coil Connector Pin 1 (PCM Driver) Signal — expected: Flashing signal when tested with a noid light or logic probe during engine cranking. With a multimeter, it may show a fluctuating low voltage.. Failure: No signal or a constant ground/voltage indicates a broken wire to the PCM or a failed PCM driver.
• Ignition Coil Primary/Secondary Resistance — expected: Primary: ~0.4-2 ohms. Secondary: ~6,000-10,000 ohms. However, these values can vary and are not always a reliable test for modern coil-on-plug units.. Failure: Readings far outside the expected range. Many technicians consider substitution (swapping coils) a more reliable test than resistance checks for this type of coil.

Scan Tool Commands That Help

• wiTECH or equivalent high-end scanner (Autel, Snap-on): Actuator Test: Ignition Coil Test / Coil On Plug Energize — Use this after confirming power at the coil connector. This command allows the technician to individually fire the #2 coil with the engine off. A successful test (hearing a spark snap with a test plug) confirms the PCM driver and wiring are functional, strongly pointing to a bad coil or spark plug.

Wiring & Ground Locations

• Cylinder #2 Coil Control Wire — PCM connector C2, Pin 50. The wire is typically Dark Blue/Tan.. This is the specific wire that carries the trigger signal from the PCM to the #2 ignition coil. A break, short-to-ground, or a backed-out pin at the connector will directly cause code P2305.
• Engine Harness Chafe Point — The main engine harness where it routes over the rear (firewall side) of the driver's side cylinder head. It can rub against a bracket stud or the sharp edge of the head.. This is a known failure point on the 3.6L Pentastar platform. Vibration can cause the harness to rub through, shorting the coil control wires to ground and causing persistent, difficult-to-diagnose ignition codes like P2305.
• Engine Ground Strap — Connects from the engine block or a bracket near the accessory drive belt to the vehicle's frame, often near the passenger-side motor mount.. A broken or corroded main engine ground strap can cause a weak or intermittent ground path for the entire ignition system, leading to weak spark, misfires, and various electrical issues, including setting this code.

Real Owner Repair Stories

• Reddit user Acrobatic_Purple_221 (2015 Jeep Wrangler JKU (same 3.6L Pentastar engine)) — P0302 and P2305 codes, CEL would return 48 hours after clearing.
  ❌ Tried (didn't work) Replaced all spark plugs, Replaced all ignition coils
  ✅ What actually fixed it The wire for ignition coil #2 was backing out of its position within the harness connector. The technician pulled the wire from the connector, adjusted the locking clip on the pin, and re-inserted it, creating a secure connection.
• Forum discussions on platform-mates (Multiple Dodge/Chrysler vehicles with 3.6L Pentastar engine) — Persistent P2305 and related misfire codes.
  ❌ Tried (didn't work) Replacing ignition coil #2 (sometimes multiple times), Replacing spark plug #2
  ✅ What actually fixed it Repairing the engine wiring harness that had chafed through on a stud or bracket at the rear of the engine, causing the coil control wire to short to ground.

When the Usual Fixes Don't Work

• While the ignition coil is the most frequent cause, multiple owner accounts confirm that replacing the coil and spark plug does not always resolve a P2305 code. In these cases, the root cause was often found in the wiring, but not in an obvious way. One owner fixed the issue by finding the specific pin for the #2 coil had backed out of the main harness connector, preventing a solid electrical connection even though the connector itself was secure. Another common, but difficult-to-find, cause has been the engine wiring harness rubbing through on a sharp edge or stud on the back of the cylinder head, causing an intermittent short in the coil's control circuit. These instances highlight the need for detailed wiring inspection when new parts don't fix the problem.

OEM Part Supersession History

• 5149168AI → 5149168AJ — Standard part revision, likely for minor manufacturing improvements or supplier change.
  Heads up: Parts are fully cross-compatible.