Home›Trouble Codes›P3480

P3480 — Cylinder 10 Exhaust Valve Control Circuit High

Manufacturer-specificPowertrain (engine & transmission)

P3480 indicates that the Powertrain Control Module (PCM) has detected a high voltage condition in the exhaust valve control circuit for cylinder 10, meaning the valve may be stuck open or the control signal is abnormal.

Symptoms

What causes it — most likely first

1. Faulty exhaust valve (cylinder 10)

The valve may be mechanically stuck open or its actuator (solenoid or hydraulic) has failed, causing a continuous high signal.

2. Defective exhaust valve control solenoid or actuator

The solenoid that opens/closes the valve can develop an internal short, sending a high voltage to the PCM.

3. Wiring harness damage or short to voltage

Chafed, corroded, or pinched wiring between the PCM and the cylinder 10 valve can create a high‑voltage condition.

4. Connector corrosion or poor contact

Moisture or corrosion at the valve control connector can produce intermittent high signals.

5. PCM output driver failure (rare)

A malfunction in the PCM’s driver circuit for cylinder 10 could falsely report a high condition, but this is uncommon.

How it's diagnosed

  1. Inspect the cylinder 10 exhaust valve and actuator for physical binding or damage.
  2. Test the valve control solenoid resistance and continuity according to service specifications.
  3. Verify wiring continuity, insulation resistance, and check for shorts to voltage between the PCM and the valve control circuit.
  4. Inspect and clean the valve control connector; reseat or replace if corrosion is present.
  5. If all hardware tests are normal, perform a PCM output driver test or substitute a known‑good PCM to confirm the module is not at fault.

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationManufacturer-specific (P1/B1/C1/U1)
Related codesP3478 — Cylinder 10 Exhaust Valve Control CircP3479 — Cylinder 10 Exhaust Valve Control CircP3481 — Cylinder 11 Deactivationintake Valve CP3482 — Cylinder 11 Deactivationintake Valve CP3483 — Cylinder 11 Deactivationintake Valve CP3484 — Cylinder 11 Deactivationintake Valve C

Frequently asked

Can the PCM be the cause of a P3480 code?

It is possible but very uncommon. Most P3480 cases are traced to the valve, its actuator, or related wiring. Replacing the PCM should be a last resort after all hardware has been verified.

Will the engine run without the cylinder 10 exhaust valve?

The engine may continue to run, but performance, fuel economy, and emissions will be negatively affected, and the condition can cause damage to the valve or exhaust system over time.

Is it safe to ignore a P3480 code?

Ignoring the code can lead to reduced engine efficiency, higher emissions, and potential damage to the valve or exhaust components. It is advisable to diagnose and repair the underlying issue.

What is the typical repair cost for this code?

Repair costs vary widely depending on the specific failure (valve, solenoid, wiring, or PCM). The most common repairs involve valve or solenoid replacement, which are generally less expensive than a PCM replacement.