P3400 - OBD II Trouble Code

Our automotive experts have put together the following information about the P3400 diagnostic trouble code. We've provided the common symptoms that occur when this code is set along with the frequent repairs that address the issues related to the P3400 code.

What Does P3400 Code Mean?

OBD-II Code P3400 is defined as a Cylinder Deactivation System

In an effort to meet fuel and emissions standards, many manufacturers are utilizing cylinder deactivation systems. This system allows the engine's control module (PCM) to disable select cylinders when additional power is not needed from the engine, such as at idle or when cruising on the highway. If the engine's control module (PCM) determines that there is a fault in the Cylinder Deactivation System, the PCM will set code P3400.

P3400 Symptoms

• Decreased engine performance
• Increased fuel consumption