HomeTrouble CodesP3407

P3407 — Cylinder 1 Exhaust Valve Control Circuit Low

Manufacturer-specificPowertrain (engine & transmission)

This code indicates an electrical fault within the control circuit for the cylinder 1 exhaust valve deactivation solenoid. The engine control module detects voltage levels lower than expected, preventing the system from disabling the exhaust valves during light load conditions. This issue is common in engines equipped with variable cylinder management technology.

Symptoms

What causes it — most likely first

1. Failed exhaust valve control solenoid

The solenoid coil often develops internal shorts or opens, causing low voltage readings.

2. Damaged wiring harness

Wires near the valve cover may chafe or melt, creating a short to ground.

3. Corroded electrical connectors

Oil contamination or moisture can increase resistance in the solenoid plug.

4. Low engine oil level

Insufficient oil pressure can prevent proper solenoid function and trigger circuit codes.

5. Blown fuse or relay

A failure in the power supply circuit will result in low voltage detection.

6. Failed Powertrain Control Module

Internal PCM driver failure is possible but statistically rare compared to external components.

How it's diagnosed

  1. Check engine oil level and condition
  2. Inspect wiring harness for chafing or burns
  3. Test solenoid resistance with a multimeter
  4. Check circuit continuity and voltage supply
  5. Perform bidirectional control test with scan tool
  6. Inspect PCM connectors only if circuit tests pass

Code facts & related codes

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

Frequently asked

Does this code require PCM replacement?

No, PCM failure is uncommon; the solenoid or wiring is the likely cause.

Is it safe to drive with this code?

Yes, but the engine may run less efficiently and consume more fuel.

Will clearing the code fix the problem?

No, the underlying electrical fault must be repaired to prevent return.

Can dirty oil cause this code?

Yes, sludge can hinder solenoid movement, but electrical faults are more common.