P0027 trouble code definition
Exhaust Valve Control Solenoid Circuit Range/Performance (Bank 1)
What the P0027 code means
P0027 is the OBD-II generic code indicating the engine control module (ECM) has determined that the variable valve lift for the exhaust valves on bank 1 of the engine takes too long to engage or does not engage.
What causes the P0027 code?
The ECM activates the exhaust valve solenoid without change to the different lift position.
The exhaust valve lift solenoid has an open or short circuit causing the valve lift to not change.
The wiring or connections to the exhaust valve lift solenoid is damaged causing a short or open circuit.
The ECM is defective or the connection to the ECM is loosing contact.
What are the symptoms of the P0027 code?
The engine lacks power depending on valve lift failed positions.
The engine may hesitate or stall on acceleration.
The engine will run erratic if the exhaust valves failed in the wrong lift position that is normal.
The Check Engine Light will come on indicating a problem with the system.
How does a mechanic diagnose the P0027 code?
Performs a visual check of the wire harness and connections for chafing or bad connections
Clears all of the engine codes to verify if the code returns
Utilizes a test control solenoid to diagnose the valve train lift operation
Checks the lift control solenoid for a short or open circuit, replaces the solenoid if it fails the test
Follows the manufacturer's specific pinpoint tests for further diagnosis of the wiring or ECM.
Common mistakes when diagnosing the P0027 code
Follow these simple guidelines to prevent mistakes:
Clear the code and retest system to verify the failure in the variable valve lift system.
Use the special tools that are necessary for proper testing.
Follow the pinpoint test, step by step, to isolate the failure on the system.
Only replace parts when directed by the pinpoint and visual test procedure.
How serious is the P0027 code?
- The engine may run erratic, stall, or hesitate.
- The engine may run rough and have a reduced fuel mileage.
- The engine may start very hard or not start at all if the ECM has failed.
What repairs can fix the P0027 code?
- Clear the fault codes and perform a road test.
- Replacing the exhaust valve lift solenoid.
- Repairing or replacing the wiring or connection to the exhaust lift solenoid.
- Repairing the ECM connector or replacing the ECM.
Additional comments for consideration regarding the P0027 code
The exhaust valve lift mechanism may bind from engine sludge build up or oil passages clogged. This can cause the shift mechanism to not move and the ECM will set the code.
Need help with a P0027 code?
YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.
This article originally appeared on YourMechanic.com as P0027 OBD-II Trouble Code: Exhaust Valve Control Solenoid Circuit Range/Performance (Bank 1) and was authored by Jay Safford.