Faulty exhaust valve control solenoid, such as a stuck plunger, worn internal seal, or open coil winding; Damaged or corroded wiring harness and connector pins at the solenoid or along the circuit path; Oil sludge or debris blocking the solenoid's hydraulic passages, preventing proper valve actuation; Low engine oil level or degraded oil that cannot build the pressure needed for the variable valve timing system; Failed or failing powertrain control module driver for the solenoid circuit, though this is less common; A mechanical issue with the exhaust camshaft phaser or timing components that overloads the solenoid

DTC codes / P00xx · Fuel and air metering and auxiliary emission controls / P0027

P0027Exhaust Valve Control Solenoid Circuit Range/Performance (Bank 1)

P0027 indicates that the powertrain control module has detected an out-of-range condition in the electrical circuit for the exhaust valve control solenoid on bank 1, which is the side of the engine containing cylinder one. The computer monitors the solenoid's command signal and expected feedback, and it sets this code when the circuit's performance does not match the commanded state within the calibrated time and voltage windows.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering and auxiliary emission controls

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Rough idle or slight misfire when the exhaust valve timing is not being controlled correctly
Reduced engine performance or poor fuel economy due to incorrect exhaust valve phasing
An audible change in exhaust note or increased engine noise under certain operating conditions
Intermittent stumbling or hesitation during acceleration if the solenoid circuit is erratic

Common causes, most likely first

Faulty exhaust valve control solenoid, such as a stuck plunger, worn internal seal, or open coil winding
Damaged or corroded wiring harness and connector pins at the solenoid or along the circuit path
Oil sludge or debris blocking the solenoid's hydraulic passages, preventing proper valve actuation
Low engine oil level or degraded oil that cannot build the pressure needed for the variable valve timing system
Failed or failing powertrain control module driver for the solenoid circuit, though this is less common
A mechanical issue with the exhaust camshaft phaser or timing components that overloads the solenoid

How to diagnose and fix it

Verify battery voltage and inspect the solenoid connector and wiring for corrosion, chafing, or loose pins
Check engine oil level and condition, then perform an oil and filter change if the oil is dirty or low
Use a scan tool to command the exhaust valve control solenoid on and off while listening for a click and watching for a change in engine behavior
Measure the solenoid's resistance with a multimeter and compare it to the manufacturer's specification for that engine
Backprobe the solenoid control circuit to confirm the powertrain control module is providing the correct command signal and ground
Remove and inspect the solenoid for sludge or metal debris, clean the mounting bore, and replace the solenoid if it fails electrical or mechanical checks
Clear the code and perform a road test with live data to confirm the circuit performance now stays within range

What the P0027 code does not always mean

A P0027 code frequently appears after an oil change interval has been stretched too far, because degraded oil cannot pressurize the exhaust valve control solenoid quickly enough to satisfy the monitor.
Technicians sometimes replace the solenoid only to find the connector pigtail has a broken wire hidden under the insulation, so a wiggle test of the harness while watching live data is a worthwhile step.
The code can be set by a mechanical problem in the exhaust cam phaser that causes the solenoid to draw abnormal current, meaning the solenoid itself may test good on the bench.
On engines with variable valve timing on both camshafts, a bank 1 exhaust solenoid fault can be misdiagnosed as a bank 1 intake solenoid fault if the technician does not confirm which solenoid the scan tool is commanding.
A weak or failing engine ground can cause the solenoid circuit to report a performance error even though the solenoid and its wiring are intact, so ground integrity should be verified before parts are replaced.

Can I keep driving with P0027?

You can usually drive the vehicle short distances to a repair shop, but avoid heavy acceleration and sustained high-speed driving because incorrect exhaust valve timing can lead to poor combustion and potential damage over time. If the engine runs roughly or stalls, stop driving and arrange a tow.

Tools that help

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