P0354 on 2006-2012 Lexus ES 350: Ignition Coil 'D' Circuit Causes and Fixes

What's Unique About the 2006-2012 Lexus ES

Ignition coil failure is a well-documented and frequent issue on the Toyota/Lexus 2GR-FE 3.5L V6 engine used in this generation of the ES 350. The problem is common enough that Toyota released an updated ignition coil part to improve reliability. Fortunately for owners, cylinder #4 is located on the front cylinder bank (Bank 2, closest to the radiator), making it the middle coil and very easy to access for diagnosis and replacement, unlike the rear coils (Bank 1) which require removing the intake manifold.

Symptoms You May Notice

• Check Engine Light is on
• VSC (Vehicle Stability Control) light may also illuminate
• Rough or shaky idle
• Engine hesitation or stumbling during acceleration
• Noticeable loss of engine power
• Reduced fuel economy
• Engine may be hard to start
• The engine may stall intermittently
• Audible popping or uneven rhythm from the engine, indicating a misfire.

Most Likely Causes

1. Failed Ignition Coil on Cylinder #4 🔴 High Probability This is a very common failure item on the 2GR-FE engine. The original coils were prone to failure, and Toyota/Lexus later released an updated part. Heat cycles and age are the primary contributors to failure.
   How to confirm: Perform a 'coil swap test.' Move the ignition coil from cylinder #4 to another easily accessible cylinder, like cylinder #6 (front bank, driver's side). Clear the codes and drive the vehicle. If the code changes to P0356, the coil is confirmed to be faulty. A multimeter can also be used to check the primary and secondary resistance of the coil against manufacturer specifications.
   Typical fix: Replace the faulty ignition coil with a new one. Since cylinder #4 is on the front bank, this is a simple repair involving removing the engine cover, disconnecting the electrical connector, removing a single 10mm bolt, and pulling the coil out. 🎬 Watch: Step-by-step 2GR-FE coil and spark plug replacement guide
   Est. part cost: $50-$120
2. Worn or Fouled Spark Plug 🟡 Medium Probability Worn spark plugs increase the electrical resistance, putting more strain on the ignition coil, which can expedite its failure. The service interval is 120,000 miles, so plugs are often overlooked.
   How to confirm: When replacing the ignition coil, remove the spark plug from cylinder #4 and inspect its condition. Look for heavy carbon deposits, oil fouling, or a worn-out electrode.
   Typical fix: Replace the spark plug. It is best practice to replace all six spark plugs at the same time with high-quality OEM (Denso or NGK) iridium plugs, though this is more labor-intensive as the rear three require intake manifold removal.
   Est. part cost: $10-$20 per plug
3. Damaged Wiring or Connector ⚪ Low Probability
   How to confirm: Visually inspect the wiring harness and electrical connector going to the cylinder #4 ignition coil. Look for any signs of cracking, fraying, melting, or corrosion on the pins. Check for a secure connection. 🎬 See how to diagnose a chewed wiring harness issue A 'wiggle test' on the harness while the engine is running can sometimes reveal an intermittent connection.
   Typical fix: Repair the damaged section of wire or replace the connector pigtail. 🎬 Watch: How to replace a broken ignition coil connector plug
   Est. part cost: $10-$30

Rare But Worth Checking

• Faulty Engine Control Module (ECM): This is extremely rare. Before condemning the ECM, all other possibilities (coil, plug, wiring) must be exhaustively ruled out. A Reddit user on r/AskMechanics reported a P0354 returning after replacing the coil and swapping coils, pointing to a deeper wiring or ECM driver issue. A scan tool may be able to perform a coil driver test to confirm an internal ECM fault.

Diagnosis Steps

1. Confirm the code P0354 is present using an OBD-II scanner.
2. Note any other codes, such as P0304, and check freeze frame data to see the conditions when the code was set.
3. Remove the plastic engine cover.
4. Locate the ignition coils on the front cylinder bank (closest to the radiator). Cylinder #4 is the middle coil.
5. Swap the ignition coil from cylinder #4 with the coil from cylinder #6 (front bank, driver's side). Mark the suspected bad coil before moving it.
6. Clear the trouble codes with the scanner.
7. Start the engine and let it run, or take a short drive until the Check Engine Light returns.
8. Re-scan for codes. If the code has changed to P0356 ('Ignition Coil F'), the coil you moved is faulty and needs to be replaced.
9. If the code P0354 returns, the problem is not the coil. Inspect the wiring and connector for cylinder #4 for damage. Check for power and ground at the connector.
10. If wiring is good, inspect the spark plug for cylinder #4.
11. If all other components check out, the issue may be with the ECM's driver circuit, which is a rare but possible failure.

Parts You'll Likely Need

• Ignition Coil (OEM #90919-A2004) — This is the most common failure point for a P0354 code on this engine. The part number listed is an updated version from Toyota/Lexus designed for better reliability. Other superseded numbers include 90919-02251 and 90919-A2002.
  Trusted brands: Denso, NGK, Genuine Toyota
  OEM price range: $80-$120
  Aftermarket price range: $40-$75
• Iridium Spark Plug (OEM #Denso FK20HR11 or NGK ILFKB6) — If the spark plugs are near their 120,000-mile service life, it's wise to replace them. A worn plug can overwork and damage a new ignition coil.
  Trusted brands: Denso, NGK
  OEM price range: $12-$20
  Aftermarket price range: $8-$15

Related Codes That Often Appear With This One

• P0304 — P0304 is a 'Cylinder 4 Misfire Detected' code. A failing ignition coil circuit (P0354) will prevent the spark plug from firing, directly causing a misfire in that cylinder.
• P0300 — This is a 'Random/Multiple Cylinder Misfire' code. Sometimes, a single failing coil can cause electrical noise or timing disruptions that lead the ECM to briefly detect misfires on other cylinders.
• P0301, P0302, P0303, P0305, P0306 — Occasionally, a severe misfire on one cylinder can cause the ECM to flag other cylinders as pending faults, as seen in a ClubLexus forum post where a user with a confirmed P0354 also had pending codes for all other cylinders.

Technical Service Bulletins (TSBs) & Recalls

• Lexus Limited Service Campaign (LSC) 9LG: Addresses the rupturing VVT-i rubber oil line, a critical issue on early 2GR-FE engines that can cause catastrophic oil loss.
• Lexus Warranty Enhancement Program ZLD: Extended warranty coverage for dashboards that become cracked, sticky, or melt due to heat and humidity, a widespread cosmetic issue on 2007-2008 models.

Mechanic-Grade Diagnostic Values

• Ignition Coil Primary Resistance — expected: 0.5 Ω ± 0.1 Ω. Failure: A reading outside of this range indicates a faulty primary winding in the coil.
• Ignition Coil Secondary Resistance — expected: ~12 kΩ. Failure: A significant deviation from this value suggests a failure in the secondary winding.
• IGT (Ignition Trigger) Signal at Coil Connector — expected: Pulsing voltage or frequency (5-20 Hz) on a multimeter when the engine is cranking or idling. An oscilloscope will show a square wave.. Failure: No signal or a steady voltage points to a problem with the wiring from the ECM or the ECM driver itself.
• IGF (Ignition Feedback) Signal at ECM — expected: A pulsing 5V signal confirming the coil has fired.. Failure: Absence of this signal is what triggers the P035x code series.

Scan Tool Commands That Help

• Toyota Techstream: Active Test: Control the Injection OFF — After confirming P0354, a technician can use this to verify if the ECM has initiated its catalyst-protection strategy by cutting fuel to cylinder #4. This confirms the ECM is actively responding to the fault.
• Toyota Techstream: Live Data: Misfire Count — To confirm that the electrical fault (P0354) is causing a physical misfire (P0304). Watching the misfire counter for cylinder #4 increment in real-time validates the symptom.

Wiring & Ground Locations

• Engine Harness Ground (Bank 2) — On the front valve cover (Bank 2, near the radiator), there is a ground bundle for the engine harness that attaches to a stud.. A loose or corroded ground at this point can cause erratic behavior and fault codes for components on the front bank, including the cylinder #4 ignition coil.
• Main Engine Ground — A primary ground strap typically connects from the cylinder head or engine block to the chassis, often near the strut tower.. A poor main engine ground can cause a host of electrical issues, including weak spark and incorrect sensor readings that could potentially lead to ignition fault codes.
• Cylinder 4 Ignition Coil Connector — The 4-pin connector directly on top of the ignition coil for the middle cylinder on the front bank.. This is where voltage and signal tests are performed. The pins correspond to +B (12V Power), IGT (Trigger), IGF (Feedback), and GND (Ground).

Real Owner Repair Stories

• YouTube user 'Prying Vato' (2007-2010 Lexus ES350) — Check engine light on, VSC light on, P0304 (Cylinder 4 Misfire Detected).
  ❌ Tried (didn't work) Swapped ignition coil from cylinder #4 to cylinder #6; the misfire code P0304 returned for the same cylinder., Replaced the spark plug in cylinder #4.
  ✅ What actually fixed it The wiring to the fuel injector for cylinder #4 was found to be chewed by rodents. Replacing the damaged fuel injector connector resolved the misfire.

OEM Part Supersession History

• 90919-02251 → 90919-A2002, 90919-A2004, 90919-A2007, and finally 90919-A2013 — Updates to improve reliability and address the common failure mode of the original coils.
  Heads up: All listed part numbers are interchangeable, but it is highly recommended to use the latest available part number (90919-A2013) for the best longevity.

Diagnostic Flowchart

Other Known Issues on This Vehicle

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

• Rupturing VVT-i Oil Supply Hose 🔴 High — Common on 2007-2009 models. The original rubber hose degrades, which can lead to a sudden, catastrophic loss of engine oil. (Ref: Lexus Limited Service Campaign (LSC) 9LG, extended until Dec 31, 2021.)
• Melting / Sticky Dashboard 🟡 Low — Very common on 2006-2008 models, especially in hot climates. The dashboard material degrades from heat and UV exposure. (Ref: Lexus Warranty Enhancement Program ZLD extended warranty coverage for this issue.)
• Timing Cover Oil Leak 🟠 Medium — A prevalent issue, particularly on earlier 2007-2009 models, though it can occur on later years. The sealant at the timing cover T-joint fails, causing a persistent oil leak. The repair is very labor-intensive.
• Water Pump Failure 🟠 Medium — The water pump is a known wear item on the 2GR-FE. Failure typically occurs after 100,000 miles, often preceded by a whining/grinding noise or a small coolant leak from the weep hole.

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: Given the high failure rate of the original ignition coils on the 2GR-FE engine, buying a used coil is generally not recommended unless it is from a very low-mileage donor vehicle and you can verify it is a later, updated part number (e.g., ending in A2004 or later). It's a risky choice for a part that is relatively inexpensive new.

Donor-vehicle mileage cap: roughly under 50000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• Check for the OEM manufacturer stamp (e.g., DENSO).
• Inspect the plastic housing for any cracks, melting, or signs of heat stress.
• Ensure the electrical connector pins are clean and free of corrosion.
• Verify the part number is a later, superseded version if possible.

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

• Engine Control Module (ECM)

Aftermarket brands forum-validated for this vehicle:

• Denso (Original Equipment Manufacturer)
• NGK

Brands owners have reported issues with on this vehicle:

• Generic, unbranded ignition coils from online marketplaces. While cheap, they have a high rate of premature failure and can cause performance issues or even damage the ECM driver.

Real Owner Stories

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

Related OBD-II Codes

• P0304 — A cylinder 4 misfire code that often accompanies P0354 when the ignition coil fails to fire the spark plug.
• P0356 — The code for an ignition coil circuit fault on Cylinder #6; it often appears during diagnosis if the faulty coil from Cylinder #4 is moved to Cylinder #6 for testing.
• P0351 — Related ignition coil circuit code for another cylinder; the 2GR-FE engine is prone to multiple coil failures due to heat cycles and age.
• P0352 — Related ignition coil circuit code; part of the same series of ignition system faults common to this vehicle's powertrain.

Frequently Asked Questions