P0354 Code Meaning, Causes, Symptoms, and Fixes

The ignition coil is a major part of the vehicle. Learn the P0354 code meaning, causes, and symptoms.

P0354 Code

The ignition coil transforms the battery’s voltage into a high-voltage current, which it then transmits to the spark plugs. These spark plugs utilize the elevated voltage to produce the spark needed for the ignition of the air-fuel mixture.

When something goes wrong with the ignition coil “D”, the engine control module (ECM) triggers the P0354 code. This guide explains the trouble code P0354 meaning, causes, symptoms, and how to fix it.

P0354 Code Definition

P0354 – Ignition Coil ‘D’ Circuit Malfunction.

What Does P0354 Code Mean?

The P0354 code indicates an issue with the ignition coil “D” primary/secondary circuit. The ignition coil D represents coil number 4 installed on engine cylinder number 4.

ignition coil Code

In order for the engine to maintain smooth operation and prevent stalling, it is important that the ignition coils function effectively.

The ignition coil holds the responsibility of accurately initiating the combustion of the fuel-air mixture within the engine cylinder.

The engine control module (ECM) of your vehicle constantly monitors the performance of the ignition coils. When your car triggers the P0354 code, it means that there is something wrong with the ignition coil located at cylinder 4. In such a situation, the air-fuel mixture will not ignition properly at the accurate timing, resulting in erratic engine performance and potential stalling.

Causes Of P0354 Trouble Code

The ECM of your vehicle triggers the P0354 code due to one or more of the below-given problems:

  • Bad ignition coil located at cylinder 4
  • Clogged throttle body passages
  • An issue with the ignition coil circuit
  • Faulty spark plug
  • An issue with the COP driver circuit
  • Intake manifold leaks
  • Electrical issues
  • Bad IAC valve
  • ECM software is outdated
  • Faulty coil pack
  • Damaged connector lock

Symptoms Of P0354 Code

When your vehicle trigger trouble code P0354, it starts to produce one or more of the below-given symptoms:

  • Poor or rough idle
  • Reduced fuel economy
  • Check engine light
  • A reduction in engine power
  • Poor acceleration
  • Hard starting conditions
  • Engine misfires
  • The vehicle goes into limp mode

How to diagnose the P0354 Code?

When the vehicle triggers the P0354 code, it is very important to find the main issue and fix it promptly. Follow the below-given steps to diagnose the P0354 code:

  • Utilize an OBD-II scan tool to access the stored error codes. Analyze the freeze frame data to gain insights into the situation. Progress through the troubleshooting process, considering any additional trouble codes that might surface. Erase the codes and perform a test drive. If the P0354 code appears again, proceed with a more comprehensive inspection.
  • Conduct a visual examination of the coil system’s wires and connections.
  • Thoroughly scrutinize the connectors for any signs of damage.
  • Examine the coil pack located at cylinder 4.
  • Examine the spark plugs for any signs of deterioration.
  • Investigate the intake manifold for potential vacuum leaks.
  • Carefully assess the condition of the primary and secondary ignition coils. If they are found damaged, change them.
  • Execute a compression test on cylinder 4 to evaluate the health of the engine’s combustion chamber.
  • Analyze the Hertz signal within the coil circuit to verify the accurate transmission of signals from the ECM.
  • Verify the tightness of connections in both the ignition coil connector and the ECM connector.
  • Upon rectifying the identified issue, use a diagnostic tool to clear the trouble codes and perform a test drive.

P0354 Code Diagnostic Mistakes

  • A prevalent error during the diagnosis of a P0354 code is misattributing a faulty ignition coil as the root cause when in fact, the issue stems from a vacuum leak.
  • Some individuals might mistakenly believe that replacing the spark plugs will resolve the issue, overlooking the possibility that the actual culprit is a vacuum leak or another underlying cause.
  • Some individuals don’t clear the codes after fixing the issue.

What repairs can fix the P0354 Code?

The replacement or repair of one or more of the below-given parts may fix the P0354 trouble code:

  • Clear the trouble codes and perform a test drive
  • Repair the intake manifold vacuum leaks
  • Replace the faulty ignition coil located at cylinder 4
  • Repair the damaged wires connected to the ECM and ignition coils
  • Replace the faulty spark plug located at cylinder 4
  • Check the health of engine cylinder number 4 by performing a compression test
  • Dix the issues related to the ECM/PCM

Repair Cost of P0354 Code

To fix the P0354 code, you need to perform the following repairs:

  • Vacuum leak repair: $60 to $400
  • Spark plug replacement: $60 to $290
  • Fuel injector replacement: $320 to $880
  • Ignition coil replacement: $140 to $250

FAQ Section

How serious is the P0354 code?

In the majority of instances, when a P0354 code is recorded, the vehicle’s operation becomes erratic, characterized by intermittent or consistent misfiring during driving. This code may also cause a sudden stop of the vehicle while accelerating. These symptoms can range from discomforting to potentially hazardous.

How many ignition coils does a car have?

The number of ignition coils in a vehicle varies according to the engine’s design and configuration. Most modern cars have one ignition coil per cylinder. Typically, the coil is installed right over the spark plug. Therefore, a 2-cylinder engine would have 2 ignition coils, a 6-cylinder engine would have 6, and so on.

What is an Ignition Coil?

In a spark-ignition engine’s ignition system, an ignition coil is employed to convert the battery’s low voltage into the significantly higher voltage levels essential for spark plug operation. The spark plug then utilizes this high-voltage current to initiate the ignition of the air/fuel mixture.

What is a Spark Plug?

The spark plug utilizes the high voltage current of the ignition coil to generate an electric spark and ignites the air-fuel mixture in the engine cylinder.

What is a Coil Pack?

A coil pack serves as a digitally controlled assembly of ignition coils, overseen by the vehicle’s ECM. It gets regular battery power and boosts it a lot, so the spark plug can create a strong spark and burn the air-fuel mixture in the combustion chamber.

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