P0352 on 2007-2012 Lexus ES: Ignition Coil 'B' Circuit Failure Causes and Fixes

What's Unique About the 2007-2012 Lexus ES

This is a very common issue on the 2GR-FE V6 engine used across many Toyota and Lexus models. The primary advantage for owners of the 2007-2012 ES is that cylinder #2 is located on the front cylinder bank (Bank 2), closest to the radiator, on the passenger side. This makes it exceptionally easy to access for diagnosis and replacement, unlike the rear bank coils which require removing the intake manifold.

Symptoms You May Notice

• Check Engine Light is on
• VSC (Vehicle Stability Control) light may also illuminate
• Engine misfire, which may feel like a shudder or stumble
• Rough or inconsistent idle
• Reduced engine power and poor acceleration
• Difficulty starting the engine
• Decreased fuel economy
• Slight hesitation during acceleration

Most Likely Causes

1. Failed Ignition Coil 🔴 High Probability → Shop Ignition Coil The original ignition coils on this engine are a known failure point, with some failing in as little as 30-50k miles. Toyota later released an updated part to improve reliability.
   How to confirm: The most effective method is to swap the ignition coil from cylinder #2 with another easily accessible coil (e.g., cylinder #4 or #6 on the same bank). Clear the codes and drive the vehicle. If the code changes to P0354 or P0356 respectively, the coil is faulty. This is a widely recommended diagnostic step in owner forums.
   Typical fix: Replace the failed ignition coil. It is held in by a single 10mm bolt and is easily accessible after removing the plastic engine cover.
   Est. part cost: $40-$120
2. Worn or Faulty Spark Plug 🟡 Medium Probability → Shop Spark Plug
   How to confirm: After confirming the coil is good, inspect the spark plug for cylinder #2. Look for heavy carbon fouling, oil contamination, or a cracked insulator. A worn-out plug with a large gap can strain the ignition coil, leading to premature failure.
   Typical fix: Replace the spark plug. If the plugs are near their service interval (typically 100,000-120,000 miles), it is best to replace all six. Use only specified Iridium plugs like the Denso FK20HR11.
   Est. part cost: $10-$25 per plug
3. Damaged Wiring or Connector ⚪ Low Probability
   How to confirm: Visually inspect the wiring harness and connector for the cylinder #2 ignition coil. Look for any signs of cracking, melting, corrosion on the pins, or broken wires. The plastic locking tab on the connector can become brittle and break, leading to a poor connection. 🎬 Watch how to diagnose a misfire caused by chewed wiring.
   Typical fix: If the connector housing is broken, it can often be replaced separately with a new pigtail. If wires are damaged, they will need to be repaired.
   Est. part cost: $15-$30 for a new connector pigtail

Rare But Worth Checking

• Faulty Engine Control Module (ECM): → Shop Engine Control Module (ECM) This is very rare. The ECM should only be considered after all other possibilities (coil, plug, wiring) have been definitively ruled out. An ECM issue might be suspected if a brand new OEM coil does not resolve the P0352 code and wiring is confirmed to be good.

Diagnosis Steps

1. Read the trouble codes with an OBD-II scanner to confirm P0352 and check for any other related codes like P0302.
2. Locate cylinder #2. On the 2GR-FE engine, it is on the front bank (closest to the radiator), on the passenger side of the engine.
3. Remove the plastic engine cover (typically held by two hex/Allen bolts).
4. Inspect the electrical connector and wiring going to the ignition coil for any visible damage.
5. Swap the ignition coil from cylinder #2 with the coil from cylinder #4 (the middle coil on the front bank). This is a simple procedure requiring only a 10mm socket.
6. Clear the trouble codes using the scanner.
7. Start the engine and go for a short drive to see if the Check Engine Light returns.
8. Re-scan for codes. If the code has changed to P0354 ('Ignition Coil 'D' Circuit'), the ignition coil you moved is faulty and needs to be replaced.
9. If the code P0352 returns, the problem is not the coil. The next step is to inspect the spark plug for cylinder #2.
10. If the spark plug appears fine, the issue may be in the wiring harness or, very rarely, the ECM.

Parts You'll Likely Need

• Ignition Coil (OEM #90919-A2007 (supersedes 90919-A2004, 90919-02250, 90919-02251, 90919-02255)) — This is the most common cause of P0352 on the 2GR-FE engine. The original coils were prone to failure, and Toyota issued an updated part.
  Trusted brands: Denso, NGK, Hitachi
  OEM price range: $90-$140
  Aftermarket price range: $40-$70
• Spark Plug (OEM #90919-01247 (Denso FK20HR11)) — A worn or fouled spark plug can cause a misfire and put extra strain on the ignition coil, potentially causing it to fail.
  Trusted brands: Denso, NGK
  OEM price range: $15-$25
  Aftermarket price range: $10-$18

Related Codes That Often Appear With This One

• P0302 — P0302 means 'Cylinder 2 Misfire Detected'. Since P0352 indicates a fault in the ignition system for cylinder 2, it directly causes a misfire, so these codes almost always appear together.
• P0300 — This code means 'Random/Multiple Cylinder Misfire'. Sometimes, a severe misfire in one cylinder can cause timing disruptions that lead the ECM to briefly detect misfires on other cylinders, though the P0352 fault is the root cause.
• P0301, P0303, P0304, P0305, P0306 — In some cases, a single failing coil on cylinder #2 can cause the computer to log pending misfire codes for all other cylinders, even though they are functioning correctly. Addressing the P0352 fault will typically resolve these other codes.

Mechanic-Grade Diagnostic Values

• Ignition Coil Primary Resistance — expected: 0.5Ω ± 0.1Ω. Failure: A reading significantly outside this range indicates a faulty coil.
• Ignition Coil Secondary Resistance — expected: ~12 kΩ. Failure: A reading significantly outside this range, or an open circuit (infinite resistance), indicates a faulty coil.
• IGT (Ignition Trigger) Signal Voltage — expected: Pulsing voltage between 0.1V and 4.5V while the engine is cranking or running.. Failure: No voltage pulse or a steady voltage indicates a problem with the ECM or the wiring.
• Ignition Coil Power Supply (B+) Voltage — expected: Battery voltage (approx. 12V) with the key in the 'ON' position.. Failure: Low or no voltage indicates a wiring or fuse issue before the coil.

Scan Tool Commands That Help

• Toyota Techstream: Misfire Count Monitoring (Data List) — While there is no specific bidirectional active test to fire an individual coil, a technician can use Techstream to monitor live misfire counts for each cylinder. This can help confirm if the misfire is isolated to cylinder #2, as expected with a P0352 code, especially during a test drive under various load conditions.

Wiring & Ground Locations

• Ignition Coil Connector (4-pin) — Directly on top of the ignition coil for cylinder #2 (front bank, passenger side).. This connector provides power, ground, and communication signals to the coil. The plastic locking tab is notoriously brittle and can break, leading to a poor connection and causing a P0352 code even with a good coil. The pinout is typically: Pin 1: IGF (Ignition Confirmation), Pin 2: IGT (Ignition Trigger), Pin 3: Ground, Pin 4: B+ (12V Power).
• Engine Harness Grounds — There are critical ground wires bolted directly to the top of both valve covers, which then attach to the chassis near the strut towers.. A loose or corroded ground connection on the valve cover can create resistance in the ignition circuit, leading to weak spark, misfires, and potentially setting ignition coil circuit codes like P0352. These should be checked if the coil, plug, and connector are confirmed to be good.

Real Owner Repair Stories

• EVIL ENERGY Blog / Technician Guide (2007-2011 Toyota Camry with 3.5L 2GR-FE (shared engine)) — Persistent P035x code (e.g., P0352) that does not resolve after swapping or replacing the ignition coil.
  ❌ Tried (didn't work) Replacing the ignition coil for the specified cylinder., Swapping the suspect ignition coil with a known-good coil from another cylinder (the code remained on the original cylinder).
  ✅ What actually fixed it The plastic ignition coil electrical connector had a broken locking tab and was not making a secure connection. Replacing the connector pigtail (splicing in a new one) resolved the intermittent connection issue and cleared the P0352 code permanently.

Diagnostic Flowchart

Other Known Issues on This Vehicle

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

• VVT-i Oil Line Rupture 🔴 High — Common on early 2007-2008 models. The original rubber hose section degrades and can burst, causing rapid and catastrophic oil loss, potentially seizing the engine. (Ref: Limited Service Campaign (LSC) 9LH / 90K covered replacement with an all-metal line.)
• Melting / Sticky Dashboard 🟡 Low — Very common on 2007-2008 models, especially in hot, humid climates. The dashboard material degrades, becoming sticky and creating a dangerous glare on the windshield. (Ref: Warranty Enhancement Program (ZLD) was issued to replace affected dashboards, but has since expired.)
• Premature Water Pump Failure 🟠 Medium — The water pump bearing can fail, causing a grinding/growling noise from the engine and coolant leaks. Failures have been reported anywhere from 50,000 to 130,000 miles.
• Harsh Shifting Transmission (U660E) 🟠 Medium — Some owners experience harsh or delayed shifting, particularly when cold. This can sometimes be related to internal transmission fluid pressure switch failures or valve body issues.

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: A used OEM ignition coil from a low-mileage donor vehicle can be a cost-effective option, as they are generally reliable after the initial problematic batches were superseded. However, given the low cost of high-quality new aftermarket coils, buying new is often the smarter choice.

Donor-vehicle mileage cap: roughly under 80000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• Check for cracks or damage to the plastic housing.
• Ensure the electrical connector pins are clean, straight, and free of corrosion.
• Avoid coils that show signs of heat damage or melting.
• Verify the part number matches the OEM or a known good superseded number.

OEM-only on this vehicle (don't cheap out):

• Engine Control Module (ECM)

Aftermarket brands forum-validated for this vehicle:

• Denso (often the original OEM supplier)
• NGK
• Hitachi

Brands owners have reported issues with on this vehicle:

• Unbranded, no-name ignition coils from online marketplaces should be avoided as their quality and longevity can be highly inconsistent.

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 accompanies P0352 when the ignition coil circuit failure causes a dead misfire.
• P0354 — Ignition Coil 'D' (Cylinder 4) Circuit — this is the code that will appear if you swap a faulty cylinder #2 coil to the middle position on the front bank.
• P0356 — Ignition Coil 'F' (Cylinder 6) Circuit — this code appears if a faulty coil from cylinder #2 is moved to the third position on the front bank during diagnostics.
• P0351 — Ignition Coil 'A' Circuit — relates to the same failure mode (faulty ignition coils) but for a different cylinder on the same 2GR-FE engine.

Frequently Asked Questions