What Does P0084 Mean?
The ECM has detected a general malfunction in the exhaust valve control solenoid circuit on bank 2. This solenoid controls oil flow to the exhaust camshaft phaser as part of the variable valve timing system. A malfunction prevents proper exhaust cam timing adjustment, which can cause rough idle, increased emissions, reduced power, and poor fuel economy.
Common Causes
35%
Faulty exhaust VVT solenoid (oil control valve) on bank 2
25%
Wiring harness damage or corroded connector at the exhaust VVT solenoid
20%
Sludge buildup restricting oil passages to the exhaust camshaft phaser
12%
Failed exhaust camshaft phaser assembly on bank 2
8%
ECM driver circuit failure
Diagnostic Steps
1
Review freeze frame data noting RPM, engine load, and oil temperature. Check engine oil level and condition — dirty or low oil is a common root cause for VVT issues.
2
Disconnect the bank 2 exhaust VVT solenoid and measure coil resistance. Typical spec is 6.9–7.9 ohms at room temperature. Replace the solenoid if out of spec.
3
With the connector unplugged, verify battery voltage on the supply wire (key on) and confirm the ECM provides a proper PWM ground signal using a scope or duty cycle meter.
4
Inspect the wiring harness for chafing, especially where it routes near the exhaust manifold. Heat damage is common on exhaust-side VVT solenoid wiring.
5
Remove the solenoid and inspect the mesh screen filter for debris. Clean or replace if clogged with sludge or metal particles.
6
Command the solenoid on/off via scan tool while monitoring the exhaust cam retard angle PID. No response with a known-good solenoid indicates a mechanical phaser failure.
Estimated Repair Cost
$150 - $650
Parts + labor, varies by vehicle and location
The ECM has detected a general malfunction in the exhaust valve control solenoid circuit on bank 2. This solenoid controls oil flow to the exhaust camshaft phaser as part of the variable valve timing system. A malfunction prevents proper exhaust cam timing adjustment, which can cause rough idle, inc...
The most common cause of P0084 (Exhaust Valve Control Solenoid Circuit (Bank 2)) is: Faulty exhaust VVT solenoid (oil control valve) on bank 2
Typical repair costs for P0084 range from $150 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Generally safe for short-distance driving. The engine may idle rough and exhibit reduced power. Exhaust VVT faults can increase emissions and reduce exhaust gas recirculation effectiveness. Avoid prolonged driving to prevent potential catalytic converter damage from altered exhaust timing.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0084 to identify the root cause.
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Quick Info
Category
Powertrain
System
Variable Valve Timing (VVT)
Difficulty
Type
Generic (SAE)
Recommended Tools
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