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P3444 Cylinder 6 Deactivation/Intake Valve Control Circuit High GuideMechanic.Com Modern automotive engines are marvels of engineering, combining power and efficiency with intelligent systems designed to optimize fuel usage.
One such system is cylinder deactivation, often used in V6 and V8 engines to reduce fuel consumption under light-load conditions.
Automakers like General Motors refer to it as Active Fuel Management (AFM), while others may call it Displacement on Demand (DoD) or Variable Cylinder Management (VCM).
This system relies on various electronic and hydraulic components, including intake valve control solenoids, to selectively deactivate cylinders.
If any part of this system malfunctions, the Engine Control Module (ECM) will trigger a diagnostic trouble code (DTC). P3444 is one such code, and it specifically refers to an electrical issue in the intake valve control circuit for cylinder 6.
This article will explain what P3444 means, how the system works, its symptoms, common causes, how to diagnose and fix it, and preventive measures.
See Also: P3443 Cylinder 6 Deactivation/Intake Valve Control Circuit Low
P3444 Cylinder 6 Deactivation/Intake Valve Control Circuit High
What Does Code P3444 Mean?
DTC Definition: P3444 – Cylinder 6 Deactivation/Intake Valve Control Circuit High
This code indicates that the voltage level in the intake valve control circuit for cylinder 6 is higher than the expected range.
This typically means that the ECM is detecting either an open circuit, excessive resistance, or possibly a short to voltage in the circuit that controls the intake valve solenoid for cylinder 6.
This fault prevents the proper activation of the intake valve control solenoid, which in turn disrupts the ability of the system to deactivate cylinder 6 during low-load conditions. As a result, the vehicle’s fuel economy and performance can be negatively affected.
How Cylinder Deactivation Works
To understand P3444, you need to know the basics of cylinder deactivation systems:
During low-load conditions (such as highway cruising), the ECM sends a command to deactivate certain cylinders by disabling the opening of intake and exhaust valves.
This is done using electrically operated solenoids mounted on the Valve Lifter Oil Manifold (VLOM).
These solenoids allow pressurized oil to collapse specially designed hydraulic lifters, which hold the valves closed.
When engine load increases, the solenoids deactivate and the cylinder resumes normal operation.
If the intake valve control solenoid for cylinder 6 receives voltage outside the acceptable range (too high), the ECM registers a P3444 fault.
P3444 Cylinder 6 Deactivation/Intake Valve Control Circuit High
Symptoms of a P3444 Code
When the P3444 code is triggered, the driver may experience one or more of the following symptoms:
Illuminated Check Engine Light (CEL)
Poor Fuel Economy – Since the cylinder cannot deactivate, fuel consumption increases.
Engine Misfire – Due to improper valve operation.
Rough Idle or Hesitation
Loss of Power Under Certain Conditions
Ticking Noise from Engine – Possibly due to lifter or solenoid malfunction.
Failed Emissions Test
In some cases, the only symptom might be the check engine light, especially if the fault is intermittent.
What Causes the P3444 Code?
There are several potential reasons why the voltage in the cylinder 6 intake valve control circuit might be too high. Common causes include:
Open or Shorted Intake Valve Solenoid (Cylinder 6)
The solenoid may be internally open or shorted to voltage, causing abnormally high readings.
Faulty Wiring or Connectors
Damaged, corroded, or disconnected wires and connectors can increase resistance or open the circuit entirely.
Valve Lifter Oil Manifold (VLOM) Malfunction
The VLOM assembly may have internal faults affecting signal voltage to the solenoids.
Poor Electrical Grounding
A missing or faulty ground can cause voltages to spike in certain circuits.
Faulty ECM/PCM (rare)
If the engine control module is malfunctioning, it may misread or incorrectly send voltages to the solenoid.
Contaminated or Incorrect Oil
While less likely to cause a high circuit code, dirty or incorrect oil can still affect solenoid behavior, leading to misdiagnoses.
P3444 Cylinder 6 Deactivation/Intake Valve Control Circuit High
How to Diagnose Code P3444
Diagnosing a high-voltage circuit error requires electrical knowledge and diagnostic tools. Here’s how a technician or knowledgeable DIYer might approach the process:
1. Scan for Codes
Use an OBD-II scanner to confirm P3444 and check for related codes such as P3441–P3443 or misfire codes.
Record freeze-frame data to understand operating conditions at the time the code set.
2. Perform a Visual Inspection
Inspect the wiring harness leading to the intake valve control solenoid.
Check for pinched, broken, or disconnected wires and connectors.
Look for oil contamination on connectors, which may interfere with voltage signals.
3. Test the Solenoid
Using a digital multimeter, check the resistance of the cylinder 6 intake valve solenoid.
Typical resistance values are between 6–10 ohms. An open circuit or infinite resistance usually confirms a faulty solenoid.
4. Test Voltage at the Connector
With the ignition on, back-probe the connector to test for excessive voltage.
If voltage exceeds specifications (usually above 12V where lower control voltage is expected), a short to power or ECM issue may be the cause.
5. Check Continuity and Shorts
Use the multimeter to test for continuity between the solenoid and the ECM.
Check for short circuits to power or ground in the wiring.
6. Inspect the VLOM Assembly
If multiple cylinder solenoids are affected, the VLOM may have an internal failure and may require replacement.
P3444 Cylinder 6 Deactivation/Intake Valve Control Circuit High
How to Fix the P3444 Code
Once the root cause is identified, appropriate repairs can be made:
1. Replace the Intake Valve Control Solenoid (Cylinder 6)
If the solenoid is faulty or shorted/open, it should be replaced.
This may require removing the intake manifold to access the VLOM.
2. Repair or Replace Damaged Wiring
Fix any damaged, corroded, or shorted wiring.
Apply dielectric grease to connectors to prevent moisture intrusion.
3. Replace or Repair the VLOM Assembly
If the fault is within the VLOM, replacing the entire unit is recommended.
4. Reflash or Replace ECM (if necessary)
If voltage signals remain abnormal after all components are confirmed functional, the ECM may require reprogramming or replacement.
5. Change Engine Oil
Replace contaminated or incorrect oil with high-quality oil of the correct viscosity as specified by the vehicle manufacturer.
P3444 Cylinder 6 Deactivation/Intake Valve Control Circuit High
Can You Drive with the P3444 Code?
Technically, the vehicle may still run and drive with a P3444 code, but it’s not advisable to ignore it for the following reasons:
Reduced Fuel Efficiency – Because cylinder 6 can’t deactivate, fuel savings are lost.
Potential Misfires – Which can lead to damage to the catalytic converter.
Increased Engine Wear – Due to incorrect valve timing or oil pressure issues.
Rough Running Conditions – That affect comfort and drivability.
If the check engine light is flashing or engine performance is noticeably degraded, driving should be avoided.
Preventive Maintenance Tips
To reduce the risk of encountering P3444 and similar codes:
Perform Regular Oil Changes
Use the correct type and viscosity of oil as per manufacturer recommendations.
Inspect Wiring Periodically
Especially around high-heat areas like the intake manifold.
Address Warning Lights Early
Don’t delay diagnostics and repairs once the check engine light comes on.
Avoid Low-Quality Parts
Use OEM or high-quality aftermarket solenoids and engine components.
Keep the Engine Clean
Prevent oil leaks that could contaminate solenoids or connectors.
Conclusion
The P3444 code indicates a high voltage condition in the intake valve control circuit for cylinder 6, which interferes with the cylinder deactivation process. This condition can result from electrical faults, failed solenoids, or malfunctioning control modules.
Though not always urgent, this code affects fuel efficiency and long-term engine health. Prompt diagnosis and repair using a logical, step-by-step approach can restore proper engine operation and prevent future issues.
Whether you’re a professional mechanic or an informed vehicle owner, understanding the role of cylinder deactivation and related trouble codes like P3444 will help you maintain your engine’s efficiency and reliability.
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