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P3445 Cylinder 6 Exhaust Valve Control Circuit/Open GuideMechanic.Com Modern engines incorporate sophisticated technologies to enhance fuel economy and performance.
One of these technologies is cylinder deactivation, also known as Displacement on Demand (DoD) or Active Fuel Management (AFM), depending on the manufacturer. This feature allows the engine to deactivate certain cylinders under low-load conditions to conserve fuel.
However, such systems rely on a network of electronic and hydraulic components to control valve operation. When something in this system malfunctions, the engine control module (ECM) detects the issue and triggers a Diagnostic Trouble Code (DTC). One such code is P3445, which specifically relates to an issue in the exhaust valve control system for cylinder 6.
This article provides an in-depth analysis of DTC P3445, including its definition, causes, symptoms, diagnosis, and solutions.
See Also: P3444 Cylinder 6 Deactivation/Intake Valve Control Circuit High
P3445 Cylinder 6 Exhaust Valve Control Circuit/Open
What Is Code P3445?
Code Definition: P3445 – Cylinder 6 Exhaust Valve Control Circuit/Open
This code indicates that the exhaust valve control circuit for cylinder 6 is experiencing an open electrical condition. This means there is a break or interruption in the electrical circuit responsible for actuating the exhaust valve in that cylinder during the cylinder deactivation process.
When this circuit is open, the control module cannot energize the solenoid that operates the oil passage to the valve lifters, preventing the exhaust valve from deactivating correctly. This can lead to poor engine performance and increased fuel consumption.
How Cylinder Deactivation Works
In engines equipped with cylinder deactivation systems, certain cylinders are turned off during light-load driving conditions to improve fuel efficiency. This is done by:
Using oil control solenoids to direct pressurized oil to hydraulic lifters in specific cylinders.
These hydraulic lifters then collapse, preventing the intake and exhaust valves from opening.
The ECM decides when to activate or deactivate cylinders based on engine load, throttle position, and other parameters.
In the case of code P3445, the ECM has detected that the circuit controlling the exhaust valve for cylinder 6 is open, meaning the system cannot properly deactivate that valve.
P3445 Cylinder 6 Exhaust Valve Control Circuit/Open
Symptoms of P3445
A P3445 trouble code may present various symptoms, some subtle and others more noticeable. Common symptoms include:
Check Engine Light (CEL) – The most obvious sign is the illumination of the CEL on the dashboard.
Decreased Fuel Efficiency – Since the system cannot deactivate cylinder 6, the engine may consume more fuel.
Rough Engine Idle – The engine may run rough at idle, especially when attempting to activate cylinder deactivation.
Engine Misfire or Hesitation – Misfiring can occur when the exhaust valve fails to operate properly.
Loss of Power – The engine may feel underpowered in certain driving conditions.
Increased Emissions – Failure to deactivate the cylinder can lead to incomplete combustion and increased exhaust emissions.
What Causes Code P3445?
There are several possible causes for an open circuit in the exhaust valve control system for cylinder 6. These include:
Faulty Exhaust Valve Control Solenoid (Cylinder 6)
The solenoid responsible for activating the valve lifter may be damaged or electrically open.
Broken or Damaged Wiring Harness
Wiring to the solenoid may be frayed, corroded, or completely severed, causing an open circuit.
Loose or Corroded Connectors
Electrical connectors may not make proper contact, resulting in loss of signal.
Malfunctioning Valve Lifter Oil Manifold (VLOM)
The VLOM assembly may be internally damaged and unable to activate the solenoid.
Faulty ECM/PCM (Engine/Powertrain Control Module)
Though rare, the control module itself may have failed or developed a software glitch.
Low or Dirty Engine Oil
Dirty oil can block internal passages, and low oil pressure may prevent the system from working properly.
P3445 Cylinder 6 Exhaust Valve Control Circuit/Open
Diagnosing the P3445 Code
Diagnosing a P3445 code requires careful inspection and the right diagnostic tools. Here’s a step-by-step guide:
1. Verify the Code
Use an OBD-II scanner to confirm the presence of code P3445.
Check for related codes, such as P3439–P3444, which could indicate broader system issues.
2. Visual Inspection
Inspect the wiring harness for any visible signs of damage, wear, or corrosion.
Check all connectors associated with the exhaust valve control solenoid on cylinder 6.
3. Solenoid Resistance Test
Disconnect the solenoid and use a multimeter to measure its resistance.
Most solenoids should read between 6 to 10 ohms. An infinite resistance reading indicates an open circuit.
4. Voltage Supply Check
With the ignition key in the “ON” position, verify that voltage is reaching the solenoid.
Use a back-probe to test for power and ground at the connector.
5. Continuity Test
Check the continuity between the solenoid connector and the ECM pin responsible for controlling cylinder 6.
If there is no continuity, the wire may be broken or internally damaged.
6. Inspect the VLOM Assembly
If all electrical checks pass, the issue may lie inside the Valve Lifter Oil Manifold. Disassembly and inspection may be required.
7. Oil Quality Inspection
Check oil levels and inspect oil condition. Dirty or sludgy oil can affect solenoid function.
P3445 Cylinder 6 Exhaust Valve Control Circuit/Open
How to Fix the P3445 Code
Once the cause is identified, the appropriate repair can be performed. Here are common fixes:
1. Replace the Faulty Solenoid
If the cylinder 6 exhaust valve control solenoid is defective, replace it with an OEM-quality part.
2. Repair or Replace Wiring and Connectors
Fix any damaged wiring, clean corroded connectors, and ensure all connections are secure.
Use dielectric grease to protect against moisture intrusion.
3. Replace the VLOM Assembly
If the VLOM is not functioning correctly, replace the entire unit. This may involve removing the intake manifold.
4. ECM/PCM Replacement or Reprogramming
If the ECM is at fault, it may need to be replaced or reprogrammed. This should be done as a last resort after all other options are ruled out.
5. Perform an Oil Change
Use the correct viscosity and high-quality synthetic oil, as recommended by the manufacturer.
P3445 Cylinder 6 Exhaust Valve Control Circuit/Open
Can You Drive with Code P3445?
While the vehicle may still operate with code P3445, it is not advisable to drive with an unresolved fault, especially for extended periods. Risks include:
Poor fuel economy
Increased emissions
Possible engine misfires
Catalytic converter damage
Long-term wear on engine components
Prompt repair ensures the vehicle runs efficiently and avoids more serious engine issues.
Preventing P3445 in the Future
To avoid encountering P3445 and similar codes:
Perform Regular Maintenance – Routine oil changes help maintain the proper operation of valve lifters and solenoids.
Use OEM Parts – High-quality parts reduce the risk of electrical faults.
Inspect Wiring Periodically – Especially in high-heat engine areas.
Respond Quickly to Check Engine Lights – Diagnosing and fixing problems early can prevent costly repairs.
Conclusion
The P3445 code signals an open circuit in the exhaust valve control system for cylinder 6, which disrupts the proper functioning of the cylinder deactivation system.
While the issue may not cause immediate breakdown, it affects engine performance, efficiency, and emissions. Diagnosing the issue involves checking the solenoid, wiring, VLOM, and oil condition.
With the right tools and approach, most P3445-related problems can be identified and resolved without extensive engine work. Addressing the code early will help preserve your engine’s performance, prevent further damage, and ensure optimal fuel efficiency.
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