April 19, 2018

Shop Tip – Subaru Outback 2.5i DTC P0026/P0028 Fixes

Shop Tip

2009 Subaru Outback 2.5i – DTC P0026 and P0028

Check engine light on; resulting initial diagnosis results in the fault code P0026 and/or P0028.

It’s always recommended to reference the factory trouble tree when diagnosing. The article references common fixes for code P0026 and P0028, that being the replacement of the variable valve lift diagnosis oil pressure switch or switches


A. Unplug both Variable Valve Lift (VVL) diagnosis oil pressure switches and measure the reference voltage, Key On Engine Off. If they match, the circuit from the oil pressure switch to the Powertrain Control Module (PCM) is presumably good.

B. The VVL solenoid turns on at 4000 RPM, at which time the oil pressure switch goes open and the PCM expects to see reference voltage.

Common fixes 

1. Replacing the variable valve lift (VVL) diagnosis oil pressure switch.

2. Drained and refilled engine oil and filter.