P3443 — Cylinder 6 Deactivation/Intake Valve Control Circuit Low

For Ford vehicles

cylinder 6 deactivation/intake valve control circuit – signal too low

powertrain (engine/transmission)

Is it safe to drive?

Short-term driving is OK In most cases the car remains drivable, possibly with reduced performance or a disabled auxiliary system. If symptoms include stalling, no-start or brake/steering warnings, treat it as urgent.

How to diagnose with an OBD scanner

  1. Read the code and freeze frame Connect an OBD2 scanner, confirm P3443 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the cylinder 6 deactivation/intake valve control for damage, corrosion, chafing or poor contact.
  4. Subsystem check Check for supply voltage at the cylinder 6 deactivation/intake valve control connector first; then measure resistance from the signal wire to ground — near-zero ohms confirms a short to ground in the harness.
  5. Subsystem check Measure reference voltage, ground and signal continuity at the component connector.
  6. Subsystem check Wiggle-test the harness while watching the signal in live data — dropouts reveal broken wires.
  7. Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P3443 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P3443 (parts and labor, USD, independent shop rates): Control module repair: $300–$1,000; Repair wiring or connectors: $80–$250; Replace the faulty sensor or actuator: $150–$500. Overall, fixing P3443 usually costs between $80 and $1,000. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

What does OBD2 code P3443 mean?

Cylinder 6 Deactivation/Intake Valve Control Circuit Low (P3443): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by open or shorted wiring in the circuit, faulty sensor or actuator of the affected circuit, poor ground connection.

What are the symptoms of P3443?

Drivers most often notice: possible limp mode depending on the affected component, the affected system operates intermittently or not at all, Check Engine Light on, increased fuel consumption in some cases.

What is the most common cause of P3443?

The most common causes are: open or shorted wiring in the circuit, faulty sensor or actuator of the affected circuit, poor ground connection.

Is it safe to drive with P3443?

In most cases the car remains drivable, possibly with reduced performance or a disabled auxiliary system. If symptoms include stalling, no-start or brake/steering warnings, treat it as urgent.

How much does it cost to fix P3443?

Control module repair — $300–$1,000; Repair wiring or connectors — $80–$250; Replace the faulty sensor or actuator — $150–$500. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

What does P3443 mean?

When P3443 appears on a scan, it means the control module has flagged a problem in the sensor and actuator circuits: cylinder 6 deactivation/intake valve control circuit low. The fault sits in the powertrain (engine/transmission) group of the OBD2 standard.

P3443 refers specifically to cylinder 6. On inline engines cylinders are counted from the front (belt end); on V-engines the numbering depends on the manufacturer, so check the firing-order diagram for your exact model. Location matters for the repair bill: some cylinders require intake manifold removal, which adds labor time.

“Circuit low” means the voltage on the cylinder 6 deactivation/intake valve control circuit stays below the expected minimum — close to ground. The usual physical reasons are a short to ground, a chafed wire touching metal, a missing supply voltage, or a failed component dragging the signal down.

The module monitors this system continuously while driving. When readings fall outside the expected range for a defined number of drive cycles, it stores P3443 and switches on the warning light. Freeze frame data saved with the code shows the exact conditions — rpm, load, temperature, speed — at the moment the fault was detected, which is the best starting point for diagnosis.

What causes P3443?

  • signal wire shorted to ground (chafed insulation)
  • failed cylinder 6 deactivation/intake valve control pulling the signal low
  • missing supply voltage to the cylinder 6 deactivation/intake valve control
  • corroded, loose or damaged connector
  • open or shorted wiring in the circuit
  • control module driver fault
  • blown fuse feeding the circuit
  • poor ground connection
  • faulty sensor or actuator of the affected circuit

Common symptoms of P3443

  • possible limp mode depending on the affected component
  • the affected system operates intermittently or not at all
  • Check Engine Light on
  • increased fuel consumption in some cases

How to diagnose P3443

  1. Connect an OBD2 scanner, confirm P3443 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Visually inspect the wiring harness and connectors related to the cylinder 6 deactivation/intake valve control for damage, corrosion, chafing or poor contact.
  4. Check for supply voltage at the cylinder 6 deactivation/intake valve control connector first; then measure resistance from the signal wire to ground — near-zero ohms confirms a short to ground in the harness.
  5. Measure reference voltage, ground and signal continuity at the component connector.
  6. Wiggle-test the harness while watching the signal in live data — dropouts reveal broken wires.
  7. Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P3443 does not return.

How to fix P3443

Start with the cheapest and most common causes before replacing expensive parts:

  • Control module repair — $300–$1,000
  • Repair wiring or connectors — $80–$250
  • Replace the faulty sensor or actuator — $150–$500

How much does it cost to fix P3443?

Repair cost depends on which component actually failed. Typical scenarios for P3443 (parts and labor, USD, independent shop rates):

  • Control module repair: $300–$1,000
  • Repair wiring or connectors: $80–$250
  • Replace the faulty sensor or actuator: $150–$500

Overall, fixing P3443 usually costs between $80 and $1,000. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Can you drive with P3443?

In most cases the car remains drivable, possibly with reduced performance or a disabled auxiliary system. If symptoms include stalling, no-start or brake/steering warnings, treat it as urgent.

Related OBD2 codes