AutoCodes – Scion – P0354 Scion

P0354 Scion Code - Ignition Coil 4 Primary/Secondary Circuit

Quick Answer

A Direct Ignition System (DIS) is a 1-cylinder ignition system in which each cylinder is ignited by one ignition coil assembly and one spark plug is connected to the end of each secondary wiring. Common causes include Faulty Ignition Coil 4, Ignition Coil 4 harness is open or shorted, Ignition Coil 4 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: P0354 Scion indicates Ignition Coil 4 Primary/Secondary Circuit.
Common causes: Common causes include Faulty Ignition Coil 4, Ignition Coil 4 harness is open or shorted, Ignition Coil 4 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 14,692

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 Aug 26, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P0354 Scion Description

A Direct Ignition System (DIS) is a 1-cylinder ignition system in which each cylinder is ignited by one ignition coil assembly and one spark plug is connected to the end of each secondary wiring. A powerful voltage, generated in the secondary wiring, is applied directly to each spark plug. The spark of the spark plugs passes from the center electrode to the ground electrode.
The Engine Control Module (ECM) determines the ignition timing and transmits the ignition (IGT) signals to each cylinder. Using the IGT signal, the ECM turns the power transistor inside the igniter on and off. The power transistor, in turn, switches the current supplied to the primary coil on and off. When the current to the primary coil is cut off, a powerful voltage is generated in the secondary coil. This voltage is applied to the spark plugs, causing them to spark inside the cylinders. As the ECM cuts the current to the primary coil, the igniter sends back an ignition confirmation (IGF) signal to the ECM for each cylinder ignition.
If the ECM does not receive any IGF signals despite transmitting the IGT signal, it interprets this as a fault in the igniter and stores a Diagnostic Trouble Code (DTC).

OBDII Code P0354 Scion - Ignition Coil 4 Primary/Secondary Circuit - AutoCodes.com — P0354 Scion Code - Ignition Coil 4 Primary/Secondary Circuit

What does this mean?

What are the Possible Causes of the DTC P0354 Scion?

Faulty Ignition Coil 4
Ignition Coil 4 harness is open or shorted
Ignition Coil 4 circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P0354 Scion?

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 P0354 Scion 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.

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Information for Specific Scion Models

P0354 2005 Scion xB — Ignition Coil 4 Primary/Secondary Circuit
P0354 2006 Scion xB — Ignition Coil 4 Primary/Secondary Circuit
P0354 2007 Scion xB — Ignition Coil 4 Primary/Secondary Circuit

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.