P3425 — Cylinder 4 Deactivation/Intake Valve Control Circuit/Open

P3425 — Cylinder 4 Deactivation/Intake Valve Control Circuit/Open. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: open or shorted wiring in the circuit, corroded, loose or damaged connector, poor ground connection.

For Ford vehicles

cylinder 4 deactivation/intake valve control circuit – open circuit

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 P3425 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 circuit/open 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 P3425 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P3425 (parts and labor, USD, independent shop rates): Replace the faulty sensor or actuator: $150–$500; Control module repair: $300–$1,000; Repair wiring or connectors: $80–$250. Overall, fixing P3425 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 P3425 mean?

P3425 — Cylinder 4 Deactivation/Intake Valve Control Circuit/Open. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: open or shorted wiring in the circuit, corroded, loose or damaged connector, poor ground connection.

Is it safe to drive with P3425?

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 P3425?

Replace the faulty sensor or actuator — $150–$500; Control module repair — $300–$1,000; 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.

How do I diagnose P3425 myself?

Start with a scan: confirm P3425, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the sensor and actuator circuits, and verify the suspect component against live data before buying parts.

What is the most common cause of P3425?

The most common causes are: open or shorted wiring in the circuit, corroded, loose or damaged connector, poor ground connection.

What does P3425 mean?

When P3425 appears on a scan, it means the control module has flagged a problem in the sensor and actuator circuits: cylinder 4 deactivation/intake valve control circuit/open. The fault sits in the powertrain (engine/transmission) group of the OBD2 standard.

P3425 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.

To set P3425, the control module compares live readings of the sensor and actuator circuits against calibrated limits, usually over several drive cycles. Alongside the code it stores a freeze frame — a snapshot of rpm, load, coolant temperature and vehicle speed at the moment of failure. Reading that snapshot first saves diagnostic time.

Common symptoms of P3425

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

What causes P3425?

  • open or shorted wiring in the circuit
  • poor ground connection
  • corroded, loose or damaged connector
  • control module driver fault
  • faulty sensor or actuator of the affected circuit

How to diagnose P3425

  1. Connect an OBD2 scanner, confirm P3425 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 circuit/open 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 P3425 does not return.

How to fix P3425

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

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

How much does it cost to fix P3425?

Repair cost depends on which component actually failed. Typical scenarios for P3425 (parts and labor, USD, independent shop rates):

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

Overall, fixing P3425 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 P3425?

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