P0084🔧 Variable valve timing (exhaust camshaft oil control solenoid)Stop and fix promptly

P0084: Exhaust Valve Control Solenoid Circuit Bank 2 (Meaning, Causes, Fixes)

Reviewed 2026-10-24 · Based on 2 cited source(s)

What P0084 means

On engines with variable valve timing, the engine computer (ECM/PCM) moves the camshaft by sending engine oil through a control solenoid. OBD-Codes.com explains that the computer drives this solenoid with a pulse width modulated (PWM) signal and watches that signal; if the voltage is out of specification or intermittent, it sets P0084 and turns on the check engine light. Bank 2 is the side of the engine that does not have cylinder number 1 (verify for your engine), so P0084 only applies to V-type and other engines with two cylinder banks. The exhaust valve control solenoid is usually on the exhaust manifold side of the cylinder head. It is a generic code that applies to all makes from 1996 on, though repair steps vary by model. Both OBD-Codes.com and RepairPal name it the Exhaust Valve Control Solenoid Circuit. RepairPal describes a solenoid that uses oil pressure to let the PCM adjust exhaust valve timing, with the code set when the PCM finds an issue with the solenoid's signal (its page mistakenly says the PCM sets 'P0984' in that sentence). The sources differ on causes: OBD-Codes.com describes electrical faults (bad connections, shorts, a failed solenoid or computer), while RepairPal adds engine oil problems and lists an oil and filter change as the common repair. RepairPal's severity (Urgent) and its 'engine may not start' symptom are stronger than anything OBD-Codes.com lists. OBD-Codes.com says this code is similar to P0085 and P0086 and may be accompanied by P0029; it is the bank 2 match for P0078.

Severity: can I keep driving?

Stop and fix promptly

Get it checked soon and avoid hard driving until then. RepairPal rates P0084 Urgent, meaning immediate action is needed, and lists decreased engine performance, higher fuel use and, in some cases, an engine that may not start. OBD-Codes.com gives no severity rating and lists milder symptoms: the check engine light, poor acceleration and lower fuel economy. Check your engine oil level right away, since RepairPal lists low or wrong-spec oil among the causes.

Common symptoms

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

  1. Wiring harness poor connection or corroded terminals (OBD-Codes.com), or another wiring issue (RepairPal)
  2. Faulty exhaust valve control solenoid (OBD-Codes.com, RepairPal)
  3. Short to power or short to ground in the solenoid wiring (OBD-Codes.com)
  4. Engine oil level too low (RepairPal only)
  5. Engine oil that doesn't meet the manufacturer's requirements (RepairPal only)
  6. Faulty engine computer (ECM/PCM) (OBD-Codes.com, RepairPal)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

  1. Check the engine oil level and make sure the oil matches your owner's manual spec; RepairPal lists low or wrong oil as common causes and an oil and filter change as the common repair.
  2. Find the bank 2 exhaust valve timing control solenoid, usually on the exhaust side of the head on the bank without cylinder 1, and look for unplugged connectors, corrosion or loose wires.
  3. OBD-Codes.com notes the solenoid can be switched on its power side or its ground side depending on the vehicle, so check a factory wiring diagram before testing. With connectors at the solenoid and computer unplugged, measure resistance end to end on each wire; it should be around 1 ohm or less, and a higher reading suggests corrosion, an open wire or a loose terminal.
  4. With the solenoid unplugged, measure resistance across its terminals and compare to the factory spec or a known good solenoid. Also check from each terminal to a good ground; OBD-Codes.com says low resistance to ground may mean the solenoid is shorted internally.
  5. To check for shorts, unplug the computer and probe the solenoid wires with a meter on volts: negative lead to ground for a short to power, or positive lead to battery positive for a short to ground. Voltage present points to a short; unplug connectors one at a time and work back toward the solenoid to find it.
  6. If wiring and solenoid test good, OBD-Codes.com suggests comparing the duty cycle commanded on an advanced scan tool with the actual signal at the solenoid using an oscilloscope or graphing multimeter at different engine speeds and loads. No signal from the computer may mean a computer fault.

Typical fixes

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

  • The engine won't start or runs poorly along with the code
  • You don't have a wiring diagram, multimeter or a scan tool that shows solenoid duty cycle
  • The code returns after an oil change and a wiring repair or new solenoid
  • Other camshaft timing codes such as P0029, P0085 or P0086 are also set

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Can I drive with P0084?

Only carefully and for a short time. RepairPal rates it Urgent and says the engine may lose performance or even fail to start, while OBD-Codes.com lists poor acceleration and lower fuel economy. Check the oil level first and get it diagnosed soon.

Where is the bank 2 exhaust valve control solenoid?

OBD-Codes.com says it is usually on the exhaust manifold side of the cylinder head, on the bank that does not contain cylinder number 1. Confirm the location in a service manual for your engine.

What's the difference between P0084, P0085 and P0086?

OBD-Codes.com groups them as similar bank 2 exhaust valve control solenoid circuit codes. P0084 is the general circuit code, set when the solenoid signal voltage is out of spec or intermittent; P0085 and P0086 are the low- and high-voltage versions.

How much does it cost to fix P0084?

Neither source gives a repair cost for P0084. It can be as simple as an oil change or a corroded connector, or it may need a new solenoid, so diagnose it before buying parts.

Sources

  1. OBD-Codes.com: P0084 Exhaust Valve Control Solenoid Circuit (Bank 2)
  2. RepairPal: P0084 Exhaust Valve Control Solenoid Circuit (rated Urgent)

Last reviewed 2026-10-24. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.