Damaged or chafed wiring in the exhaust valve control circuit, such as a short to ground or an open circuit; Failed exhaust valve control solenoid or actuator that has an internal short or high resistance; Corroded or loose electrical connector at the solenoid or at the powertrain control module; Faulty powertrain control module driver circuit, though this is less common; Mechanical binding in the exhaust valve mechanism that overloads the circuit and causes low current feedback

DTC codes / P34xx · Auxiliary emission controls / P3407

P3407Cylinder 1 Exhaust Valve Control Circuit Low

Q: What does code P3407 mean?

Cylinder 1 Exhaust Valve Control Circuit Low. P3407 indicates that the powertrain control module has detected an abnormally low voltage or current on the control circuit for cylinder 1's exhaust valve, which is part of a variable valve timing or cylinder deactivation system. The computer expects a specific electrical signature when commanding the valve and sees a value below the acceptable threshold, so it flags the circuit as faulty.

P3407 indicates that the powertrain control module has detected an abnormally low voltage or current on the control circuit for cylinder 1's exhaust valve, which is part of a variable valve timing or cylinder deactivation system. The computer expects a specific electrical signature when commanding the valve and sees a value below the acceptable threshold, so it flags the circuit as faulty.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaAuxiliary emission controls

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Rough idle or misfire sensation, especially when the engine is cold or under light load
Reduced engine power or sluggish acceleration due to improper valve operation
Poor fuel economy as the engine management strategy compensates for the fault
In some cases, a noticeable ticking or tapping noise from the valve train area

Common causes, most likely first

Damaged or chafed wiring in the exhaust valve control circuit, such as a short to ground or an open circuit
Failed exhaust valve control solenoid or actuator that has an internal short or high resistance
Corroded or loose electrical connector at the solenoid or at the powertrain control module
Faulty powertrain control module driver circuit, though this is less common
Mechanical binding in the exhaust valve mechanism that overloads the circuit and causes low current feedback

How to diagnose and fix it

Perform a visual inspection of the exhaust valve control solenoid and its wiring harness for obvious damage, corrosion, or loose connections
Use a scan tool to command the exhaust valve actuator on and off while monitoring the circuit voltage or current to confirm the fault
Disconnect the solenoid and measure resistance across its terminals, comparing to the manufacturer's specification
Check for continuity and short-to-ground on the control circuit wires between the solenoid and the powertrain control module
If the circuit and solenoid test good, verify the mechanical operation of the exhaust valve and rocker arm for binding or excessive clearance
Replace the faulty solenoid or repair the wiring as needed, then clear the code and verify the repair with a test drive

What a low circuit code really means

A low circuit code often results from a short to ground rather than an open circuit, so pay close attention to wire routing near hot or moving components.
The exhaust valve control solenoid may test fine at room temperature but fail when hot, so perform resistance checks both cold and after warming the engine.
A mechanical fault in the valve train can cause the solenoid to draw excessive current and set a low circuit code, so do not overlook mechanical inspection.
This code can be set by a weak battery or charging system issue that causes momentary voltage drops, so always verify battery and charging system health first.
After repairs, the code may not clear immediately because the PCM requires a specific number of drive cycles to re-evaluate the circuit.

Can I keep driving with P3407?

You can usually drive the vehicle with this code, but avoid aggressive acceleration and heavy loads until the fault is repaired, as prolonged driving may cause catalytic converter damage or further engine wear.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.