P0302 on 2010-2012 Honda Crosstour: Cylinder 2 Misfire Causes & Fixes

What's Unique About the 2010-2012 Honda CROSSTOUR

The 2010-2012 Crosstour is equipped with a 3.5L V6 engine featuring Honda's Variable Cylinder Management (VCM) system. This system deactivates certain cylinders—often the rear bank (1, 2, 3)—to save fuel. Unfortunately, this process can lead to oil consumption and spark plug fouling on the deactivated cylinders, a known issue that directly causes misfire codes like P0302. Honda issued Technical Service Bulletin A13-079 and settled a class-action lawsuit (Soto, et al. v. American Honda Motor Co. Inc.) acknowledging that misfires on cylinders 1-4 can be caused by piston rings rotating and aligning, leading to fouled spark plugs. As a result of the lawsuit, Honda extended the warranty on these components to 8 years with unlimited mileage.

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 vibrating idle, especially when the engine is warm
• Hesitation or stumbling during acceleration
• Solid or flashing Check Engine Light (CEL)
• Reduced engine power and poor throttle response
• Decreased fuel economy
• Smell of unburnt gasoline from the exhaust
• Noticeable engine vibration when the 'ECO' light is on

Most Likely Causes

1. Fouled Spark Plug (Cylinder 2) 🔴 High Probability Honda TSB #A13-079 directly links P0302 to spark plug fouling. The VCM system's operation causes oil to be consumed and contaminate the plugs in the rear cylinders (1, 2, and 3), which are frequently deactivated.
   How to confirm: Remove the spark plug from cylinder 2 and inspect it. It will likely have black, oily, or wet deposits, especially when compared to a plug from the front bank (e.g., cylinder 5).
   Typical fix: Replace the fouled spark plug. It is highly recommended to replace all six 🎬 See this step-by-step tutorial for replacing Crosstour V6 spark plugs. spark plugs at the same time using OEM-spec plugs to ensure proper performance and longevity.
   Est. part cost: $60-$150 for a set of 6 OEM-quality plugs.
2. Failed Ignition Coil (Cylinder 2) 🟡 Medium Probability Ignition coils are a common wear item. A fouled spark plug increases the electrical resistance, putting extra stress on its coil and leading to premature failure.
   How to confirm: Swap the ignition coil from cylinder 2 with another cylinder (e.g., cylinder 1 or 5). Clear the codes and drive. If the code changes to P0301 or P0305, the ignition coil is faulty. 🎬 Watch: How to diagnose if your misfire is a plug or coil.
   Typical fix: Replace the failed ignition coil. Many owners choose to replace all three rear coils or all six at once as a preventative measure.
   Est. part cost: $55-$100 per coil.
3. Internal Engine Issue (Piston Rings) 🟡 Medium Probability This is the root cause identified in TSB #A13-079 and the class-action lawsuit. The piston rings on VCM-active cylinders (1-4) can become stuck with carbon or rotate until their gaps align, allowing oil to bypass into the combustion chamber and foul the spark plug.
   How to confirm: This is difficult to confirm without professional diagnosis. Persistent P0301-P0304 codes after replacing plugs and coils, combined with documented high oil consumption, strongly suggest this issue. A cylinder leak-down or compression test can help diagnose it.
   Typical fix: The official Honda fix involves a partial engine disassembly to clean the pistons and replace the piston rings in the affected cylinders, a major and expensive repair. Many owners proactively install a VCM disabling device (e.g., VCMuzzler II, S-VCM Controller) to prevent the system from activating, which can stop or significantly slow the progression of oil consumption and plug fouling.
   Est. part cost: $100-$150 for a VCM disabler; $2000+ for piston ring replacement at a dealership if not covered by the extended warranty.
4. Clogged or Failed Fuel Injector ⚪ Low Probability
   How to confirm: If spark components are confirmed good, the injector is the next suspect. An advanced scan tool can perform an injector balance test. Alternatively, the injector can be swapped with another cylinder to see if the misfire code follows it, though this is more labor-intensive.
   Typical fix: Replace the faulty fuel injector.
   Est. part cost: $70-$150 per injector

Rare But Worth Checking

• Valves Out of Adjustment:

Diagnosis Steps

1. Read the code with an OBD-II scanner and confirm it is P0302. Note any other codes present, especially P0300, P0301, P0303, or P0304.
2. Locate cylinder 2. On the Crosstour's 3.5L V6, the rear bank of cylinders (closest to the firewall) is 1-2-3, from passenger to driver side. The front bank is 4-5-6. Cylinder 2 is the middle cylinder on the rear bank.
3. Swap the ignition coil from cylinder 2 with the coil from cylinder 5 (an easier-to-access front cylinder). Clear the codes and run the engine. If the code changes to P0305, the coil is bad and needs replacement.
4. If the code remains P0302, turn off the engine and remove the ignition coil from cylinder 2 again. Remove the spark plug using a 5/8" spark plug socket with an extension.
5. Inspect the spark plug. Look for heavy, black, wet oil fouling or dense carbon buildup. Compare it to a plug from a front cylinder (e.g., cylinder 5). If it is significantly dirtier, this is the classic symptom of the VCM issue.
6. Replace the spark plug in cylinder 2. It is strongly recommended to replace all six plugs with the correct OEM part (NGK or Denso Iridium).
7. If the misfire persists after new plugs and known-good coils, the issue may be with the fuel injector or an internal engine mechanical problem (piston rings, valve adjustment).
8. For persistent issues, professional diagnosis is recommended. This may include a compression and leak-down test to check for piston ring or valve sealing problems.
9. To prevent recurrence, seriously consider installing a VCM disabling device like a VCMuzzler II or S-VCM Controller. These devices modify the coolant temperature reading sent to the ECU, preventing it from activating VCM mode and stopping the associated oil consumption 🎬 Watch: How to install a VCM disabling device in 5 minutes. and plug fouling.

Parts You'll Likely Need

• Spark Plugs (Iridium) (OEM #NGK ILZKR7B11 (7751) or DENSO SXU22HCR11S (3461)) — Almost always fouled with oil and carbon due to the VCM system issue described in TSB A13-079. This is the most common immediate cause of the misfire.
  Trusted brands: NGK, Denso
  OEM price range: $18-$26 per plug
  Aftermarket price range: $10-$18 per plug
• Ignition Coil (OEM #30520-R70-A01 (superseded by 30520-R70-S01)) — The second most likely cause. A fouled spark plug can overwork and damage the ignition coil, causing it to fail.
  Trusted brands: Hitachi (OEM supplier), NGK, Denso
  OEM price range: $90-$125
  Aftermarket price range: $55-$85
• VCM Disabling Device — An aftermarket solution to prevent the root cause. It stops the VCM system from activating, thereby preventing the oil consumption and spark plug fouling that leads to P0302 and other misfires.
  Trusted brands: VCMuzzler II, S-VCM Controller, VCMTuner
  OEM price range: N/A
  Aftermarket price range: $100-$150

Related Codes That Often Appear With This One

• P0300 — If the misfire is severe, intermittent, or affecting multiple cylinders, the ECM may log a P0300 (Random/Multiple Misfire) code in addition to the specific cylinder code.
• P0301, P0303, P0304 — These codes indicate misfires in other cylinders. The underlying VCM issue often affects cylinders 1, 2, and 3 on the rear bank, and sometimes cylinder 4. Seeing these codes together is a very strong indicator of the TSB-related piston ring and oil consumption problem.

Technical Service Bulletins (TSBs) & Recalls

• A13-079: MIL Comes On With DTC P0301, P0302, P0303, or P0304
• A13-078, A13-080, A13-081, A13-082: Related TSBs for other VCM-equipped models covered under the same warranty extension.

Platform-Specific Known Issues

• Honda Technical Service Bulletin A13-079 was issued for 2010-2012 Crosstour models for misfire codes P0301-P0304. The bulletin states, "piston rings on certain cylinders may rotate and align which can lead to spark plug fouling."
• This issue was the subject of a class-action lawsuit (Soto, et al. v. American Honda Motor Co., Inc.), which resulted in a warranty extension to 8 years/unlimited miles for diagnosis and repair of this specific problem.

Mechanic-Grade Diagnostic Values

• Fuel Injector Resistance — expected: 10-18 Ohms. Failure: A reading significantly outside this range, or one that is very different from the other injectors, indicates a faulty injector.
• Fuel Pressure (at idle) — expected: 48-55 PSI. Failure: Pressure significantly below this range could indicate a weak fuel pump or clogged filter, causing a lean condition and misfires.
• Short-Term and Long-Term Fuel Trims — expected: Between -5% and +5%. Failure: High positive values indicate the engine is compensating for a lean condition (potential vacuum leak or fuel delivery issue), while high negative values indicate a rich condition (leaking injector).

Scan Tool Commands That Help

• Honda HDS (Honda Diagnostic System): Misfire Counter Live Data — To monitor misfire events in real-time for each cylinder. This helps confirm if the misfire is constant or intermittent and if it's isolated to cylinder 2, which is crucial for diagnosis before swapping parts.
• Honda HDS (Honda Diagnostic System): Power Balance Test — This function allows a technician to sequentially disable the fuel injector for each cylinder. When cylinder 2 is disabled, if there is no change in engine RPM or smoothness, it confirms that cylinder 2 was not contributing, pinpointing the misfire.

Wiring & Ground Locations

• G101 — On the right side of the engine compartment, often on the engine block or cylinder head.. G101 is a primary ground for the engine control module (PCM) and multiple engine sensors and actuators, including the ignition coils. A corroded or loose G101 ground can cause erratic behavior, including weak spark and intermittent misfires that are difficult to diagnose.
• Cylinder 2 Ignition Coil Connector — On the cylinder 2 ignition coil, which is the middle coil on the rear bank of cylinders, near the firewall.. The 3-pin connector provides power and ground to the coil, and receives the trigger signal from the PCM. Checking for 12V power, a good ground, and the signal with a multimeter or oscilloscope can confirm if the coil is receiving the correct inputs.
• PCM Connector C, Pin C06 — At the Powertrain Control Module (PCM). The PCM is typically located in the cabin, behind the glove box or center console area.. Pin C06 on connector C is the specific circuit that controls the fuel injector for cylinder 2. If the injector and its local wiring are good, a continuity test from this pin to the injector connector can identify a break in the engine wiring harness.

Real Owner Repair Stories

• CrosstourOwnersClub.com forum user (2010 Honda Crosstour EX-L, ~100,000 miles) — Flashing check engine light, P0302, P0303, P0304, and P0300 codes. ECO mode engaging roughly.
  ❌ Tried (didn't work) Initially replacing only the spark plugs.
  ✅ What actually fixed it The owner found that the spark plugs were severely fouled with oil, consistent with the VCM issue. The final fix was to replace all six spark plugs and install a VCM disabling device (VCMuzzler) to prevent the issue from recurring. The codes did not return after this.

OEM Part Supersession History

• 30520-R70-A01 → 30520-R70-S01 — This is a common supersession for Honda parts, likely indicating a minor revision in manufacturing, materials, or internal design for improved reliability.