AutoCodes – Toyota – P0356 2004 Toyota Highlander

P0356 2004 Toyota Highlander Code - Ignition Coil 6 Primary/Secondary Circuit

Quick Answer

The ignition system on the vehicle uses individual ignition coils for each cylinder. Common causes include Faulty Ignition Coil 6, Ignition Coil 6 harness is open or shorted, Ignition Coil 6 circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0356 2004 Toyota Highlander indicates Ignition Coil 6 Primary/Secondary Circuit.
Common causes: Common causes include Faulty Ignition Coil 6, Ignition Coil 6 harness is open or shorted, Ignition Coil 6 circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 5,454

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0356 2004 Toyota Highlander Description

The ignition system on the vehicle uses individual ignition coils for each cylinder. The Engine Control Module (ECM) controls each ignition coil operation. The ECM sends a ON/OFF signal to energize the ignition coil to create a spark at the spark plug when a spark is required at the cylinder.

OBDII Code P0356 2004 Toyota Highlander - Ignition Coil 6 Primary/Secondary Circuit - AutoCodes.com — P0356 2004 Toyota Highlander Code - Ignition Coil 6 Primary/Secondary Circuit

What does this mean?

What are the Possible Causes of the DTC P0356 2004 Toyota Highlander?

Faulty Ignition Coil 6
Ignition Coil 6 harness is open or shorted
Ignition Coil 6 circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P0356 2004 Toyota Highlander?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0356 2004 Toyota Highlander code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0356 2004 Toyota Highlander code?

Need more information on how to fix the P0356 2004 Toyota Highlander code? Get Access to Factory Service Manuals

Need Help with the Code?

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0356 2004 Toyota Highlander Code

1. What does code P0356 mean on a 2004 Toyota Highlander?

Code P0356 indicates an issue with the Ignition Coil 6 Primary/Secondary Circuit, meaning the engine control module (ECM) has detected a malfunction in the ignition coil for cylinder 6.

2. What are the symptoms of code P0356 in a 2004 Toyota Highlander?

Common symptoms include engine misfires, rough idling, reduced fuel efficiency, hesitation during acceleration, and the check engine light turning on.

3. What causes code P0356 to appear on a 2004 Toyota Highlander?

Possible causes include a faulty ignition coil, damaged wiring or connectors in the ignition coil circuit, a malfunctioning ECM, or a worn-out spark plug in cylinder 6.

4. Can I drive my 2004 Toyota Highlander with code P0356?

Driving with code P0356 is not recommended, as it can lead to further engine damage, reduced performance, and increased emissions.

5. How do I diagnose code P0356 on a 2004 Toyota Highlander?

Start by inspecting the ignition coil and its wiring for damage. Use a multimeter to test the coil's resistance and check for proper voltage at the connector. Swap the coil with another cylinder to see if the issue follows the coil.

6. How do I fix code P0356 on a 2004 Toyota Highlander?

Repairs may involve replacing the ignition coil for cylinder 6, repairing damaged wiring or connectors, replacing a faulty spark plug, or, in rare cases, reprogramming or replacing the ECM.

7. How much does it cost to fix code P0356 on a 2004 Toyota Highlander?

The cost to fix code P0356 can range from $50 to $200 for a replacement ignition coil, plus labor if done by a technician. Additional repairs for wiring or ECM issues may increase the cost.

8. Can a bad spark plug cause code P0356 on a 2004 Toyota Highlander?

Yes, a worn or damaged spark plug in cylinder 6 can cause ignition coil issues and trigger code P0356.

9. Will clearing the code P0356 solve the problem on my 2004 Toyota Highlander?

Clearing the code will turn off the check engine light temporarily, but the underlying issue must be resolved to prevent the code from returning.

10. How can I prevent code P0356 on a 2004 Toyota Highlander?

Regular maintenance, including replacing spark plugs and ignition coils as needed and inspecting wiring for wear, can help prevent P0356 from occurring.