Damaged or chafed wiring in the cylinder 6 deactivation valve control circuit, often near exhaust heat or sharp edges; Failed cylinder 6 deactivation/intake valve solenoid or actuator; Corroded or loose electrical connector at the valve solenoid; Short to ground inside the valve solenoid coil; Faulty powertrain control module driver for that circuit, though this is less common; Oil sludge or debris blocking the valve mechanism, causing the solenoid to draw excessive current and set a low-circuit code

DTC codes / P34xx · Auxiliary emission controls / P3443

P3443Cylinder 6 Deactivation/lntake Valve Control Circuit Low

Q: What does code P3443 mean?

Cylinder 6 Deactivation/lntake Valve Control Circuit Low. P3443 indicates that the powertrain control module has detected an abnormally low voltage on the control circuit for the cylinder 6 deactivation/intake valve, which is part of a variable displacement or cylinder deactivation system. The circuit is either shorted to ground, open, or the valve actuator itself has failed, preventing the computer from properly commanding the valve to switch between active and deactivated states.

P3443 indicates that the powertrain control module has detected an abnormally low voltage on the control circuit for the cylinder 6 deactivation/intake valve, which is part of a variable displacement or cylinder deactivation system. The circuit is either shorted to ground, open, or the valve actuator itself has failed, preventing the computer from properly commanding the valve to switch between active and deactivated states.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaAuxiliary emission controls

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Rough idle or misfire-like shuddering when the engine transitions between cylinder modes
Reduced fuel economy because the engine may stay in full-cylinder mode
Hesitation or stumble during light-throttle cruising when deactivation should occur
In rare cases, a loud ticking or tapping noise from the affected cylinder bank
Possible limp-home mode with reduced power if the fault escalates

Common causes, most likely first

Damaged or chafed wiring in the cylinder 6 deactivation valve control circuit, often near exhaust heat or sharp edges
Failed cylinder 6 deactivation/intake valve solenoid or actuator
Corroded or loose electrical connector at the valve solenoid
Short to ground inside the valve solenoid coil
Faulty powertrain control module driver for that circuit, though this is less common
Oil sludge or debris blocking the valve mechanism, causing the solenoid to draw excessive current and set a low-circuit code

How to diagnose and fix it

Inspect the wiring harness and connector at the cylinder 6 deactivation valve for chafing, corrosion, or loose pins
Measure resistance of the valve solenoid with a multimeter and compare to the manufacturer's specification
Check for a short to ground on the control wire between the PCM and the solenoid
Verify power and ground at the solenoid connector with the key on and during a commanded activation test
If the circuit tests good, remove and inspect the valve for sludge or mechanical binding
Replace the faulty solenoid or valve assembly if resistance or mechanical checks fail
Clear the code and perform a relearn or drive cycle to confirm the repair

What a low circuit code really tells you

A low-circuit code does not automatically mean the solenoid is bad; a shorted wire or corroded connector can pull the voltage down just as easily.
Oil sludge from infrequent oil changes is a common hidden cause because it restricts valve movement and makes the solenoid draw more current than normal.
Technicians sometimes replace the valve only to find the code returns because the PCM driver was damaged by a shorted solenoid that was not diagnosed first.
The cylinder 6 deactivation valve may share a ground or power feed with other circuits, so a fault elsewhere can set this code without any problem in the valve itself.
On some engines, the deactivation system is disabled automatically when other codes are present, so always check for stored misfire or camshaft codes before condemning the valve circuit.

Can I keep driving with P3443?

You can usually drive the vehicle short distances to a repair shop, but avoid heavy acceleration and prolonged highway driving because the engine may remain in full-cylinder mode and run inefficiently. If the check engine light starts flashing or the engine runs very rough, stop driving and have it towed.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.