P0028 trouble code definition
Intake Valve Control Solenoid Circuit Range/Performance (Bank 2)
What the P0028 code means
P0028 is the OBD-II generic code indicating the engine control module (ECM) has determined that the variable valve lift for the intake valves for bank 2 will not engage.
What causes the P0028 code?
The ECM activates the intake valve solenoid for bank 2, but the valve lift mechanism did not change.
The intake valve lift solenoid for bank 2 is shorted or has an open circuit.
The wiring or connections have opens or shorts between the ECM and the valve lift solenoid.
The connector to the valve lift solenoid gets contaminated by oil and shorts out.
What are the symptoms of the P0028 code?
- The engine can lack power if the valve lift fails in a position that is not optimal for operation.
- The engine runs rough or stalls.
- The engine can have a hesitation on acceleration.
- The Check Engine Light comes on.
How does a mechanic diagnose the P0028 code?
- Checks all of the wiring and connections for damage
- Checks and clears the codes, then retest the system to verify the failure
- Uses the test solenoid to verify that the valves can change from a low to high lift
- Follows the manufacturer's specific pinpoint tests for further diagnosis
Common mistakes when diagnosing the P0028 code
Follow these simple guidelines to prevent mistakes:
- Verify the failure by clearing the code and seeing if the problem is still present.
- Do not attempt any diagnosis without the special tools, such as a test solenoid.
- Follow the pinpoint tests, step by step, to isolate the failure.
- Only replace parts as directed by the pinpoint or visual test.
How serious is the P0028 code?
- The engine may run erratic or stall when coming to a stop.
- The engine can hesitate and have a lack of power during acceleration.
- The engine may start very hard or run too lean.
What repairs can fix the P0028 code?
Verifying the failure and replacing the variable valve lift solenoid after testing
Testing the solenoid installed will verify if the valves work or will not shift, indicating a clogged passage in the solenoid
Repairing or replacing the wiring and connections to the variable valve intake lift solenoid
Repairing ECM connector or replacing the ECM
Additional comments for consideration regarding the P0028 code
The variable valve intake lift mechanism is actuated by the intake lift solenoid. This opens and closes oil pressure to the valve lift mechanism to shift the valve from low to high lift lobe on the camshaft.
Need help with a P0028 code?
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This article originally appeared on YourMechanic.com as P0028 OBD-II Trouble Code: Intake Valve Control Solenoid Circuit Range/Performance (Bank 2) and was authored by Jay Safford.