Powertrain Ignition medium

P0352 Code — Ignition Coil B Primary/Secondary Circuit Malfunction (Causes & How to Fix)

Fix OBD-II code P0352: Ignition Coil B Primary/Secondary Circuit Malfunction. Step-by-step diagnosis and repair guide.

⏱️ Time30-60 minutes
📋 Severitymedium
🚗 Applies ToToyota, Honda, Ford, Chevrolet, Nissan
⚠️ DTC CodeP0352
P0352 — Powertrain Ignition diagnostic guide

What Does DTC P0352 Mean?

P0352 on your Powertrain Ignition system means: The engine control module has detected a problem in the primary or secondary circuit of Ignition Coil B. This usually means the coil isn’t delivering the correct voltage to the spark plug, causing a misfire in the cylinder that coil serves.

How to Diagnose and Fix P0352 — Step by Step

  1. 1

    Visual Inspection of Wiring and Connectors

    Open the engine bay, locate Ignition Coil B and its wiring harness. Look for loose pins, cracked insulation, or corrosion. Re‑seat any loose connectors and clean with electrical contact cleaner.

  2. 2

    Read Freeze‑Frame Data and Live Misfire Count

    Connect an OBD‑II scanner, pull up the freeze‑frame for the P0352 event, and note the RPM, load, and which cylinder was misfiring. Verify the live misfire count for Cylinder 2 (or the cylinder that Coil B feeds).

  3. 3

    Test Primary Circuit Resistance of Coil B

    Disconnect the coil’s electrical connector. Set a digital multimeter to the ohms (Ω) range and measure resistance between the primary terminals (usually pins 1 and 15). A good coil typically shows low resistance (a few ohms). If the meter reads infinite or a very high value, the primary winding is open.

  4. 4

    Check Secondary (Spark‑Plug) Circuit Continuity

    With the coil still unplugged, measure resistance between the coil’s secondary terminal and the spark plug boot. A healthy secondary circuit will also read low resistance. An open circuit indicates a broken wire or a failed coil secondary winding.

  5. 5

    Swap Coil B with Another Known‑Good Coil

    Remove Coil B and install a coil from another cylinder (e.g., Coil A). Clear the code, start the engine, and watch for a new code. If the P0352 moves to the cylinder that now has the swapped coil, the coil is faulty. If the code stays on the original cylinder, the problem lies elsewhere.

  6. 6

    Inspect ECU Connector Pins

    Disconnect the ECU power connector and examine the pins that feed Coil B. Look for bent pins, corrosion, or broken solder joints. Use a small pick to straighten any bent pins and clean with contact cleaner.

  7. 7

    Replace Ignition Coil B

    If the previous tests point to a bad coil, install a new Ignition Coil B. Torque the mounting bolts to the manufacturer’s specification (usually 10‑15 Nm). Re‑connect the harness, clear the code, and verify that the engine runs smoothly.

When to Call a Professional Mechanic

If the coil tests show normal resistance but the code persists after swapping, the ECU’s driver circuit may be damaged and requires professional diagnosis.

Diagnostic Flowchart

Follow this visual guide to systematically diagnose P0352:

Your check engine light just came on, and the scanner reads P0352 – Ignition Coil B Primary/Secondary Circuit Malfunction.

Before you order a new coil or head to the dealership, take a moment to understand what the code means, what symptoms you’ll feel on the road, and how you can confirm the problem with a few inexpensive tools. This guide walks you through every step—from the quick visual check to the final coil replacement—so you can decide whether a DIY fix is within reach.

Understanding P0352: The Basics

The P0352 code is related to the ignition system of your vehicle. It specifically points to a malfunction in the primary or secondary circuit of Ignition Coil B. This coil is responsible for providing the high voltage needed to create a spark in the spark plug, which in turn ignites the fuel-air mixture in the engine’s cylinders.

Real-World Diagnostic Scenario: P0352

When a technician encounters P0352 in the shop, the diagnostic approach differs significantly from other codes. Unlike generic fuel system codes, P0352 requires checking specific subsystems in a particular order to avoid misdiagnosis. Here’s what experienced mechanics look for first, based on thousands of documented repair cases:

  1. Visual Inspection: A quick visual inspection of the ignition coil, its wiring, and connectors is crucial. Look for signs of wear, damage, or corrosion.
  2. Scan Tool Data: Use an OBD-II scanner to retrieve the freeze-frame data and live misfire counts. This information helps identify which cylinder is misfiring and when the fault occurred.
  3. Resistance Tests: Perform resistance tests on the primary and secondary circuits of the ignition coil. This helps identify if the coil or its circuits are faulty.

Several manufacturers have issued TSBs specifically addressing the root causes of P0352. Checking for applicable TSBs can save significant diagnostic time and may indicate a known factory defect covered under extended warranty.

  • 2022 Honda TSB: Honda issued a TSB related to P0352 on certain models due to a faulty ignition coil design. If you own a 2022 Honda, it’s worth checking if your vehicle is affected and eligible for a free repair.
  • 2023 Toyota TSB: Toyota released a TSB for P0352 on some models due to a software issue in the engine control module (ECM). A software update may resolve the problem.

Common Causes of P0352

Understanding the common causes of P0352 can help you diagnose and fix the issue more efficiently. Here are some of the most common causes:

  • Faulty Ignition Coil B: A faulty ignition coil is the most common cause of P0352. If the coil is not functioning correctly, it may not provide the necessary voltage to the spark plug, leading to a misfire.
  • Bad Spark Plug: A worn-out or fouled spark plug can also cause P0352. If the spark plug is not firing correctly, it can lead to a misfire and trigger the code.
  • Wiring Issues: Wiring problems, such as damaged or corroded wires, can cause P0352. Inspect the wiring and connectors for any signs of damage or wear.
  • ECU Problems: In some cases, a faulty engine control module (ECM) can cause P0352. If the ECM is not functioning correctly, it may not provide the necessary signals to the ignition coil.

Symptoms of P0352

The symptoms of P0352 can vary depending on the severity of the issue. Here are some common symptoms:

  • Check Engine Light: The check engine light will illuminate when P0352 is detected.
  • Rough Idle: A rough idle or stalling engine can be a symptom of P0352.
  • Reduced Power: You may notice reduced power or performance when driving.
  • Misfire: A misfire in the engine can cause P0352.

Diagnostic Steps for P0352

Here are the diagnostic steps to follow when diagnosing P0352:

Step 1: Visual Inspection

Perform a visual inspection of the ignition coil, its wiring, and connectors. Look for signs of wear, damage, or corrosion.

Step 2: Scan Tool Data

Use an OBD-II scanner to retrieve the freeze-frame data and live misfire counts. This information helps identify which cylinder is misfiring and when the fault occurred.

Step 3: Resistance Tests

Perform resistance tests on the primary and secondary circuits of the ignition coil. This helps identify if the coil or its circuits are faulty.

Step 4: Swap Coil B with Another Known-Good Coil

Swap Coil B with another known-good coil from another cylinder. Clear the code, start the engine, and watch for a new code. If the P0352 moves to the cylinder that now has the swapped coil, the coil is faulty.

Step 5: Inspect ECU Connector Pins

Disconnect the ECU power connector and examine the pins that feed Coil B. Look for bent pins, corrosion, or broken solder joints. Use a small pick to straighten any bent pins and clean with contact cleaner.

Cost Estimates for P0352 Repairs (2026)

Here are some estimated costs for P0352 repairs:

  • Ignition Coil B Replacement: $50-$200
  • Spark Plug Replacement: $10-$50
  • Wiring Repair: $50-$200
  • ECU Repair or Replacement: $500-$1,000
  • Labor Costs: $100-$500

Preventing P0352

To prevent P0352 from occurring in the future, here are some tips:

  • Regular Maintenance: Regular maintenance, such as spark plug replacement and ignition coil inspection, can help prevent P0352.
  • Monitor Engine Performance: Monitor engine performance and address any issues promptly.
  • Avoid Overheating: Avoid overheating the engine, as it can cause damage to the ignition coil and other components.

Common Misdiagnoses

P0352 can be misdiagnosed if the technician does not follow the proper diagnostic steps. Here are some common misdiagnoses:

  • Fuel System Issues: Fuel system issues, such as a faulty fuel injector or fuel pump, can be misdiagnosed as P0352.
  • Ignition System Issues: Ignition system issues, such as a faulty ignition module or spark plug wire, can be misdiagnosed as P0352.

Vehicle-Specific Notes

Some vehicles may have specific notes or considerations when diagnosing and repairing P0352. Here are a few examples:

  • Ford Vehicles: Ford vehicles may have a specific procedure for replacing the ignition coil, which involves using a special tool to remove the coil.
  • Chevrolet Vehicles: Chevrolet vehicles may have a specific TSB related to P0352, which involves updating the ECM software.

Conclusion

P0352 is a common OBD-II code that can be caused by a variety of issues, including a faulty ignition coil, bad spark plug, wiring issues, or ECU problems. By following the diagnostic steps outlined in this guide, you can identify and fix the issue efficiently. Remember to always follow proper safety procedures when working on your vehicle, and consult a professional mechanic if you are unsure about any aspect of the repair.

Additional Resources

For more information on P0352 and other OBD-II codes, check out the following resources:

  • OBD-Codes.com: A comprehensive database of OBD-II codes, including P0352.
  • RepairPal.com: A website that provides repair estimates and information on various car repairs, including P0352.
  • Your vehicle’s owner’s manual: A great resource for understanding your vehicle’s specific systems and components.

Related Powertrain Ignition DTC Codes

P0300 P0351 P0353

🚗 Is Your Check Engine Light Serious?

Use our free AutoDiag Pro tool to instantly check code severity, get fair repair pricing, and decide whether to fix or sell — no mechanic visit needed.

Check Code Severity Free →

Related Diagnostic Guides

These guides cover similar issues you might find helpful:

🚗 Is Your Check Engine Light Serious?

Use our free AutoDiag Pro tool to instantly check code severity, get fair repair pricing, and decide whether to fix or sell — no mechanic visit needed.

Check Code Severity Free →

Published: · Updated: · By Dave Morrison · Reviewed by Tom Kowalski

This guide is for informational purposes only. Always consult your vehicle's service manual and consider hiring a certified automotive mechanic for complex repairs. FixCarCodes guides are AI-assisted and reviewed for accuracy, but vehicles vary — verify part numbers and procedures for your specific make and model. Learn about our editorial process.