HomeTrouble CodesP3428

P3428 — Cylinder 4 Deactivationintake Valve Control Circuit High

Manufacturer-specificPowertrain (engine & transmission)

P3428 indicates the engine control module has detected an abnormally high voltage signal in the control circuit for the intake valve on cylinder 4’s deactivation system. This usually means the circuit is open or shorted to power, preventing proper cylinder deactivation.

Symptoms

What causes it — most likely first

1. Faulty cylinder deactivation solenoid (lifter or actuator)

The intake valve solenoid on cylinder 4 is internally shorted or mechanically stuck, causing a high-voltage signal in its control circuit.

2. Wiring or connector damage in the solenoid control circuit

Chafed, broken, or corroded wires between the PCM and cylinder 4 deactivation solenoid, or a poor connection at the solenoid or PCM.

3. Short to power in the control circuit

A wire in the solenoid control circuit is shorted to battery voltage, creating a high-voltage signal at the PCM.

4. Faulty or stuck cylinder deactivation lifter

The mechanical lifter for cylinder 4’s intake valve is seized or damaged, preventing proper operation and affecting the circuit signal.

5. Engine oil level or quality issue

Low oil level, incorrect oil viscosity, or degraded oil can prevent proper hydraulic operation of the deactivation system, indirectly affecting circuit signals.

6. PCM (engine computer) failure (rare)

An internal fault in the PCM’s driver circuit for the solenoid is possible but uncommon; verify all other causes first.

How it's diagnosed

  1. Retrieve and document all stored trouble codes and freeze-frame data.
  2. Inspect the wiring harness and connectors for the cylinder 4 deactivation solenoid for damage, corrosion, or loose connections.
  3. Measure the resistance of the cylinder 4 deactivation solenoid; compare to manufacturer specifications (typically 5–20 ohms).
  4. Check for battery voltage short in the solenoid control circuit using a multimeter or oscilloscope.
  5. Verify engine oil level and condition; ensure correct viscosity and no excessive contamination.
  6. If all other causes are ruled out, test the PCM’s output signal to the solenoid using a scan tool or oscilloscope (rarely necessary).

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationManufacturer-specific (P1/B1/C1/U1)

Frequently asked

Is the PCM usually the cause of P3428?

No. While the PCM controls the circuit, PCM failure is a very rare cause of P3428. The solenoid, wiring, or mechanical components are far more likely culprits.

Can I drive with P3428?

You can drive short distances, but prolonged driving may reduce fuel economy and could lead to additional engine wear or emissions issues. Diagnose and repair promptly.

Does P3428 always mean the solenoid is bad?

Not always. The solenoid is the most common cause, but wiring damage, oil issues, or mechanical lifter problems can also trigger this code. Thorough diagnosis is needed.

Will replacing the oil fix P3428?

Only if the oil level was low or the oil was degraded/contaminated. If oil quality is poor, an oil change may help, but it won’t resolve wiring or mechanical faults.