P0352 on 2010-2012 Hyundai Santa Fe 3.5L V6: Ignition Coil 'B' Circuit Causes and Fixes

What's Unique About the 2010-2012 Hyundai Santa Fe

The good news for owners of the 2010-2012 Santa Fe with the 3.5L V6 is the location of cylinder #2. On this transversely mounted engine, the cylinders are in two banks: Bank 1 (cylinders 1, 3, 5) against the firewall, and Bank 2 (cylinders 2, 4, 6) at the front by the radiator. Since P0352 points to cylinder #2, the faulty component is right on top and easy to access, making this a much simpler and cheaper repair than if the issue were on the rear bank (codes P0351, P0353, P0355), which requires removing the upper intake manifold.

Symptoms You May Notice

• Check Engine Light is on
• Flashing Check Engine Light under load
• Engine misfire or running rough, especially at idle
• Noticeable loss of power and poor acceleration
• Difficulty starting the engine
• Reduced fuel economy
• Engine may stall, particularly at low speeds when coming to a stop

Most Likely Causes

1. Failed Ignition Coil on Cylinder #2 🔴 High Probability → Shop Ignition Coil Ignition coils are a common wear item that fail from age and repeated heat cycles. The location on top of the engine exposes them to significant heat.
   How to confirm: Perform a 'coil swap' test. Label and swap the ignition coil from cylinder #2 with the one from cylinder #4 (the middle cylinder on the same front bank). Clear the codes and run the engine. If the code changes to P0354, the coil is definitively bad.
   Typical fix: Replace the faulty ignition coil. It is held on by a single 10mm bolt. Apply a small amount of dielectric grease to the inside of the new coil's boot before installation.
   Est. part cost: $40-$90
2. Worn or Fouled Spark Plug 🟡 Medium Probability → Shop Spark Plug Spark plugs are a regular maintenance item. An old plug with a wide gap puts extra strain on the ignition coil, which can cause the coil's circuit to fail or the PCM to flag a fault.
   How to confirm: After confirming the coil is good with a swap test, remove the spark plug from cylinder #2. Inspect it for a cracked insulator, heavy carbon buildup, oil fouling, or an excessively worn electrode.
   Typical fix: Replace the spark plug. It is highly recommended to replace all six spark plugs as a set if they are near or over their service interval (typically 60,000-100,000 miles) to ensure balanced engine performance.
   Est. part cost: $10-$25 per plug
3. Damaged Ignition Coil Wiring or Connector ⚪ Low Probability → Shop Ignition Coil The plastic connector and wiring can become brittle over time due to engine heat and vibration, leading to cracks, loose pins, or corrosion. The locking tab on the connector is particularly prone to breaking.
   How to confirm: Visually inspect the electrical connector and the wiring harness leading to the cylinder #2 ignition coil. Look for any signs of damage, melting, corrosion, or pins that may have backed out of the connector. Wiggle the connector with the engine running to see if it induces a misfire.
   Typical fix: Repair the damaged section of wiring or replace the pigtail connector if it's broken.
   Est. part cost: $15-$30 for a new connector pigtail

Rare But Worth Checking

• Leaking Valve Cover Gasket: → Shop Engine Valve Cover A very common issue on Hyundai V6 engines is a leaking front valve cover gasket. This allows oil to fill the spark plug tubes, which will saturate and destroy the ignition coil and boot. If you remove the ignition coil and find liquid oil in the spark plug tube, the valve cover gasket (or its integrated tube seals) has failed and must be replaced to solve the root cause. This leak can also drip oil onto the alternator, causing it to fail.
🎬 Watch this step-by-step guide to replacing the V6 valve cover gasket.
• Faulty Powertrain Control Module (PCM): → Shop Engine Control Module (ECM) This is extremely rare. Before condemning the PCM, all other possibilities (coil, plug, wiring) must be exhaustively ruled out. A faulty PCM driver circuit for coil #2 would cause the P0352 code to return immediately even with a known-good coil and wiring.

Diagnosis Steps

1. Connect an OBD-II scanner and confirm that P0352 is present. Note any other codes, especially P0302.
2. Locate cylinder #2. On the 3.5L V6, it is the first cylinder on the front bank (closest to the radiator) on the passenger side of the engine.
3. Swap the ignition coil from cylinder #2 with the coil from cylinder #4 (the middle cylinder on the same front bank). This is the most reliable way to confirm a bad coil.
4. Clear the trouble codes with the scanner.
5. Start the engine and let it run for a minute or take a short drive.
6. Re-scan for codes. If the code is now P0354 ('Ignition Coil 'D' Circuit'), the ignition coil you moved is bad and must be replaced.
7. If code P0352 returns, the coil is not the problem. Remove the coil and spark plug from cylinder #2.
8. Inspect the spark plug for damage, wear, or fouling. Check for oil inside the spark plug tube, which indicates a leaking valve cover gasket that must be repaired.
9. If the plug is good and there's no oil, carefully inspect the wiring and connector for cylinder #2. Test for power, ground, and signal at the connector using a multimeter and a wiring diagram.

Parts You'll Likely Need

• Ignition Coil (OEM #27300-3F100) — This is the most common failure part for a P0352 code. Internal windings break down over time from heat and vibration. This part number may supersede 27300-2G000.
  Trusted brands: Hyundai (OEM), NGK, Delphi, Denso, Hitachi
  OEM price range: $85-$160
  Aftermarket price range: $40-$90
• Spark Plug (Iridium) (OEM #18846-11070) — Often replaced as preventative maintenance when replacing a coil, as a worn plug can cause a new coil to fail prematurely. Recommended to replace all six at once.
  Trusted brands: NGK (Laser Iridium), Denso (Iridium TT)
  OEM price range: $15-$25
  Aftermarket price range: $10-$20
• Valve Cover Gasket Set (Front Bank) (OEM #22441-3C110) — Required only if oil is found in the spark plug tubes. The gasket set includes the main gasket and the spark plug tube seals. Failure to replace a leaking gasket will cause the new ignition coil to fail from oil saturation.
  Trusted brands: Hyundai (OEM), Fel-Pro, Mahle
  OEM price range: $30-$50
  Aftermarket price range: $15-$30

Related Codes That Often Appear With This One

• P0302 — This code means 'Cylinder 2 Misfire Detected.' P0352 is the electrical fault that prevents the spark plug from firing, which directly causes the misfire. These two codes almost always appear together.
🎬 See this video explaining how to diagnose a cylinder 2 misfire.
• P0300 — This code for 'Random/Multiple Cylinder Misfire' can appear if the misfire in cylinder #2 is severe enough to disrupt the engine's overall rotational speed, causing the PCM to detect instability across other cylinders.

Technical Service Bulletins (TSBs) & Recalls

• TSB 15-01-020: Supersedes earlier bulletins and provides an ECM software update for 2010-2012 3.5L Santa Fe models to address potential engine stalling when coming to a stop due to electrical load management, and to update diagnostic logic.
• TSB 12-FL-004: An earlier TSB providing an ECM software update for some 3.5L vehicles that may experience a Check Engine Light.

Platform-Specific Known Issues

• A known issue on some Hyundai V6 engines is a leaking front valve cover gasket that can drip oil into the spark plug tubes, destroying the ignition coils. It can also drip onto the alternator, causing premature failure.
• A small number of owners have experienced engine stalling at low speeds when braking. Hyundai released a TSB (15-01-020) for an ECM software update to address this issue by improving the engine's electrical load management.

Diagnostic Flowchart

Other Known Issues on This Vehicle

Issues unrelated to this code that are worth knowing about as an owner of this generation:

• Timing Chain Tensioner Rattle on Startup 🟠 Medium — Commonly reported. A brief 1-2 second rattle after the vehicle has been sitting for a few hours. While often considered a non-critical noise by dealers, it can be caused by a worn timing chain tensioner or failing oil pump losing its prime.
• Front Valve Cover Gasket Leak Causing Alternator Failure 🔴 High → Shop Engine Valve Cover — This is a very common and well-documented failure pattern. The front valve cover gasket leaks oil directly onto the alternator below, causing it to fail prematurely. Symptoms include a battery light, dimming lights, and a whining noise. (Ref: While TSBs exist for older 3.3L models for this issue (e.g., TSB 23-01-076H-2), the design flaw persists in the 3.5L.)
• Failing Oil Pressure Switch/Sensor 🟠 Medium — The oil pressure switch on the 3.5L Lambda II is known to fail, causing a significant oil leak. While not directly causing P0352, a major oil pressure loss could contribute to other engine issues like CVVT faults.
• Engine Stalling at Low Speeds 🟡 Low — Some owners reported the engine stalling when coming to a stop. Hyundai addressed this with a service campaign for an ECM software update to better manage alternator load on the engine at low RPMs. (Ref: TSB 15-01-020)

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• P0302 — Cylinder 2 Misfire Detected; often appears alongside P0352 when the ignition coil circuit fault prevents the spark plug from firing.
• P0354 — Ignition Coil 'D' (Cylinder 4) Circuit; this code will appear if you successfully perform a 'coil swap' test by moving a faulty coil from cylinder 2 to cylinder 4.
• P035X — General series for ignition coil circuit faults (P0351-P0356) which are common on this engine due to heat-related coil failure or oil contamination from leaking valve cover gaskets.
• TSB 23-01-076H-2 — While not a trouble code, this TSB relates to the front valve cover gasket leak that frequently causes oil to contaminate the ignition system and alternator on Hyundai V6 engines.

Frequently Asked Questions