P3426 — Cylinder 4 Deactivation/Intake Valve Control Circuit Performance

For Ford vehicles

cylinder 4 deactivation/intake valve control circuit – range/performance problem

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 P3426 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 4 deactivation/intake valve control for damage, corrosion, chafing or poor contact.
  4. Subsystem check Measure reference voltage, ground and signal continuity at the component connector.
  5. Subsystem check Wiggle-test the harness while watching the signal in live data — dropouts reveal broken wires.
  6. Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P3426 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P3426 (parts and labor, USD, independent shop rates): Control module repair: $300–$1,000; Replace the faulty sensor or actuator: $150–$500; Repair wiring or connectors: $80–$250. Overall, fixing P3426 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 are the symptoms of P3426?

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

How much does it cost to fix P3426?

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

What does OBD2 code P3426 mean?

Cylinder 4 Deactivation/Intake Valve Control Circuit Performance (P3426): 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 faulty sensor or actuator of the affected circuit, blown fuse feeding the circuit, corroded, loose or damaged connector.

Will P3426 clear itself?

Sometimes P3426 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

Is it safe to drive with P3426?

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.

What does P3426 mean?

P3426 is logged by the onboard diagnostics when the sensor and actuator circuits does not behave as expected. The official definition is “Cylinder 4 Deactivation/Intake Valve Control Circuit Performance”. This is a powertrain (engine/transmission) category code.

P3426 refers specifically to cylinder 4. 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.

This code does not appear from a single bad reading: the module must see the fault condition repeat under defined operating conditions before it turns on the warning light. The freeze frame captured with P3426 — engine load, rpm, temperature, speed — tells you exactly when the problem occurs, so reproduce those conditions when testing.

Common symptoms of P3426

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

What causes P3426?

  • open or shorted wiring in the circuit
  • control module driver fault
  • blown fuse feeding the circuit
  • faulty sensor or actuator of the affected circuit
  • corroded, loose or damaged connector

How to diagnose P3426

  1. Connect an OBD2 scanner, confirm P3426 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 4 deactivation/intake valve control for damage, corrosion, chafing or poor contact.
  4. Measure reference voltage, ground and signal continuity at the component connector.
  5. Wiggle-test the harness while watching the signal in live data — dropouts reveal broken wires.
  6. Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P3426 does not return.

How to fix P3426

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

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

How much does it cost to fix P3426?

Repair cost depends on which component actually failed. Typical scenarios for P3426 (parts and labor, USD, independent shop rates):

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

Overall, fixing P3426 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 P3426?

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