What Is Cylinder Deactivation System Bank 1? Fixing Guide

When you notice a sudden decline in your car’s engine power while driving, you should be aware that something is amiss with your engine.

To diagnose the engine issue, you must have an auto service technician utilize an OBD II scanner.

When examined, it may display the P3400 code, which indicates troubleshooting for cylinder deactivation system bank 1.

What Is Cylinder Deactivation System Bank 1?

cylinder deactivation system bank 1

P3400 is an engine diagnostic code that indicates ‘Cylinder Deactivation System – Bank 1’.

When the Powertrain Control Module (PCM) detects an issue, malfunction, or failure in any part or element of the system that prevents the cylinder from working normally, this code is activated.

Note that the code can also be engaged when any portion or part of the cylinder deactivation system breaks or malfunctions, triggering the code when it is not supposed to.

The cylinder deactivation system is a technology that enables the engine to operate with fewer cylinders than a regular engine.

When a cylinder powers the engine, it uses less gasoline while providing the same power as a traditional engine.

‘Bank 1’ is the cylinder comprising cylinder one on V-type engines. Dodge, Honda, Chevrolet, GMC, Pontiac, and Chrysler are vehicles most frequently detected with this problem.

What Could Be The Cause Of P3400?

The most prevalent causes of code p3400 cylinder deactivation system bank 1 in all autos are the same and involve one or several of these:

  • A faulty cylinder disables the solenoid.
  • Insufficient oil supply
  • Engine oil that is damaged, deteriorated, or inappropriate
  • Electrical cabling or adapters that are faulty, burned, shorted, rusted, or unconnected
  • Incorrect or faulty mass air flow sensor, intake air temperature, or gas sensor. You should consider replacing or resetting the mass air flow sensor. Click here to see what to do after replacing the MAF sensor.
  • A defective or misaligned throttle position sensor
  • The oil level or pressure in the lifter is low.
  • Lifter error
  • An open or short cylinder deactivation circuit exists in the cylinder deactivation solenoid correlation.
  • Electrical connection failure in the cylinder deactivation solenoid circuit
  • A VVT (Variable Valve Timing) oil control solenoid is not working properly.
  • PCM or other control module error
  • Although this is an unusual circumstance, it necessitates locating the defect before changing control systems.

When this code appears, the vehicle will run on all eight cylinders rather than just four. This problem reduces fuel efficiency and increases exhaust emissions.

Although diagnostic issue code P3400 is not normally considered serious, it must be diagnosed as soon as possible.

What Are The Common Symptoms Of Code P3400?

Again, common code p3400 symptoms are the same for all vehicles and may involve some or all of the below. However, the severity of one or more symptoms can differ from one vehicle to another.

  • The check engine light illuminates, begins to tremble, and the engine’s efficiency decreases.
  • Fuel use has skyrocketed.
  • In some situations, the engine’s operating condition may rough or stall regularly, and the PCM may unexpectedly enter dangerous or lame mode, persisting until the error is resolved.

How To Diagnose And Fix the P3400 Code

How To Diagnose And Fix the P3400 Code

Code P3400 must be rectified as promptly as possible to prevent further issues.

If you lack the requisite auto repair knowledge or skills, we suggest that you should have your car evaluated by an expert technician for accurate diagnosis.


The following are the processes that the technician takes when diagnosing the code.

  • Examine the cylinder oil pressure and level.
  • Retrieve all DTCs recorded in the PCM using the OBD-II scanner.
  • Diagnose any outdated DTCs and oil pressure in the PCM.
  • Using an OBD-II scanner, eliminate fault codes.
  • Then, using the scan tool, test the deactivation of cylinder #1. In normal operation, the solenoid component will vibrate and rattle. If the solenoid fails, check the oil lines and reinstall it.
  • Test the cylinder number 7 deactivation solenoid in case the number 1 solenoid is functioning right.
  • Then examine solenoid no. 7: When the solenoid is functional, it will vibrate and create a popping noise. If the solenoid is not operating, check the oil lines and change them.
  • Inspect the oil path to the lifters if the 7th solenoid operates.
  • If necessary, flush the oil channels. The cylinder block may need to be disassembled by the mechanic.
  • Should the fuel lines be clogged, remove the lifter.

Note: The most typical error in diagnosing this is failing to inspect the oil lines for debris and contaminants.

When moving from V4 to V8 mode, clogged oil lines restrict engine oil levels and keep the cylinder and lifter parts from operating correctly.

Double-check the oil lines to avoid spending money on needless components and maintenance.

How Do I Fix Code P3400?

There is no way to solve this error codes by yourself because the proposed solutions vary by make and model.

Hiring a professional technician with auto repair experience to diagnose and repair your P3400 code could be the better decision.

However, if you want to do it at home, you should first research your vehicle’s most prevalent P4300 code issues.

Your repair manual may provide the necessary information to determine what’s causing your P3400 issue.

Numerous online automotive repair resources are accessible to assist you in resolving your diagnostic issue codes.

Remember that each automaker has its own set of maintenance instructions for its vehicles. For example, p3400 code honda pilot might not work for Pontiac.

Always refer to your vehicle’s service manual when troubleshooting error codes to avoid messing things up.

Regarding expenses, cylinder deactivation system bank 1 repair costs will range from $70 to $150 per hour. The predicted repair time is determined by the true source of the issue and the specialist’s ability.

This code trouble can be quite complicated, and it may be required to disassemble the entire engine to analyze it fully.

This is a large job, even for a skilled mechanic, so don’t start removing the vehicle if you are not certain how!

The Bottom Line

To sum up, P3400 indicates an issue with the cylinder deactivation system bank 1. When your car experiences this code, its engine performance suffers, and its fuel usage levels up.

Typically, the code does not result in immediate harm to your car. But, if you do not evaluate the code for an extended period, the engine will begin to fail.

It is really difficult to solve the issue by yourself. To handle this engine trouble code, please seek the assistance of a skilled mechanic.

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