P2311 Code: Ignition Coil “D” Secondary Circuit

Vehicles are equipped with ignition coils that act like a transformer, turning the low voltage power from the vehicle’s battery into high voltage by saving it briefly and then sending it to the spark plug in a short pulse. When an ignition coil develops a problem, the P2311 code or other related trouble codes could trigger.

What Does the P2311 Code Mean?

Diagnostic trouble code (DTC) P2311 code means “Ignition Coil ‘D’ Secondary Circuit.” This code triggers when the powertrain control module (PCM) detects an abnormal voltage in a secondary control circuit of an ignition coil. There are several secondary ignition coil circuits, each corresponding to a particular ignition coil. This code corresponds to the circuit labeled with the letter D.

The secondary ignition coil circuit consists of the secondary windings inside of the coil, the spark plug, and the spark plug wire (if equipped). Issues with this circuit could lead to problems with the spark plug’s functionality, which can lead to engine-related issues.

You may also watch this video to understand how ignition coil works:

Note: The definition of the P2311 code can differ depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.

What are the Common Causes of the P2311 Code?

The P2311 code is commonly caused by the following issues:

• Defective ignition coil
• Faulty spark plug wire
• Malfunctioning relay
• Blown fuse
• Open or shorted wiring or wiring connectors
• Worn spark plug

What are the Common Symptoms of the P2311 Code?

Here are the common symptoms of the P2311 code:

• Illuminated check engine light
• Engine misfires
• Reduced engine performance
• Reduced fuel efficiency
• Other related trouble codes could trigger

How to Diagnose the P2311 Code

While the P2311 code indicates that the ignition coil is faulty, it is possible that it is not the source of the problem. To fix this diagnostic trouble code (DTC), you must first correctly identify the cause. You may need to visually inspect the affected components and wiring, which can be challenging if you are unfamiliar with its layout. It could also require the use of specialized tools and knowledge. If you are unfamiliar with DIY repairs, we recommend consulting a trusted mechanic to properly diagnose the problem.

Interested in diagnosing the problem yourself? Check out the video below to learn more.

How to Fix the P2311 Code

The repair process for OBD-II trouble codes can vary greatly between vehicle models. As a result, know that there won’t be a fix-all solution. If you don’t have much experience troubleshooting DTCs, then we recommend leaving the task to a trusted professional.

If you think you have the knowledge and skills for the task, then the first step to fixing the code is to properly diagnose its cause. After identifying the cause of the P2311 code, you can start consulting online repair resources and guides for possible fixes. Chilton repair manuals can be useful. An ALLDATA DIY subscription might be better, as it provides factory repair information for other people interested in DIY repairs.