Cylinder 2 Exhaust Valve Control Circuit Low
Diagnostic trouble code P3415 indicates that the powertrain control module (PCM) has detected a low voltage condition in the control circuit for the cylinder 2 exhaust valve deactivation mechanism. This typically occurs in vehicles equipped with cylinder deactivation (variable displacement) systems when the circuit voltage falls below the manufacturer's specified threshold.
While not immediately dangerous, this code affects engine performance and fuel economy. It should be diagnosed and repaired soon to prevent potential internal engine damage or drivability issues.
Common symptoms
- Illuminated Check Engine Light
- Decreased fuel efficiency
- Engine misfires or runs rough
- Lack of engine power
- Vehicle fails to enter cylinder deactivation mode
Likely causes
- Faulty cylinder 2 exhaust valve control solenoid
- Wiring harness damage, shorts, or open circuits in the valve control circuit
- Poor electrical connection at the valve control solenoid connector
- Low engine oil level or poor oil pressure
- Restricted oil passages to the cylinder deactivation lifters
- Faulty Powertrain Control Module (PCM) (rare)
What to check before replacing parts
Check the engine oil level and condition.
Look for: Low oil level, extremely dirty oil, or incorrect oil viscosity can prevent the hydraulic cylinder deactivation system from functioning properly.
Visually inspect the wiring and connector for the cylinder 2 exhaust valve control solenoid.
Look for: Look for frayed wires, melted insulation, corrosion, or loose pins that could cause a low voltage condition or open circuit.
Test the resistance of the cylinder 2 exhaust valve control solenoid using a multimeter.
Look for: Compare the resistance reading to the manufacturer's specifications. An out-of-spec reading indicates an internally shorted or open solenoid.
Check for voltage and ground at the solenoid connector with the key on, engine off (or commanded via scan tool).
Look for: The presence of proper reference voltage and a good ground. Lack of voltage indicates a wiring issue between the PCM and the solenoid.
Perform an oil pressure test using a mechanical gauge.
Look for: Ensure engine oil pressure meets manufacturer specifications, as low pressure can prevent the deactivation lifters from operating correctly.
This page explains the generic P3415 definition and is general reference information, not a diagnosis for your specific vehicle. Actual causes, severity, and repairs vary by make, model, engine, and mileage — always confirm with a scan tool and a qualified technician before replacing parts.
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