Some 2020 Encore GX and 2021 Trailblazer models equipped with the 1.2L engine (RPO LIH) may have an illuminated Check Engine MIL and DTCs P0521 (Engine Oil Pressure Sensor Performance) and/or P06DE (Engine Oil Pressure Control Solenoid Valve Stuck On) and P06DD (Engine Oil Pressure Control Solenoid Valve Stuck Off) set. If these conditions are found, perform the engine oil pump failure screening test using GDS 2.
Before performing the test, delete any stored DTCS, run the engine for 15 minutes or until engine coolant temperature reaches a minimum of 175°F (79°C).
If DTCs P0521, P06DE, and/or P06DD set, engine oil pump replacement (Fig. 10) and lower crankcase extension port inspections are required. Refer to the appropriate Service Information for oil pump replacement.
Fig. 10
With the engine oil pan, engine oil pressure control solenoid valve, and oil pump removed, inspect the three oil pump ports (Fig. 11, #1) and the engine oil pressure control solenoid valve port (Fig. 11, #2) for any debris.
Fig. 11
Remove any debris from the ports. Do not scratch or damage any surfaces or use brush-type tools or cloth materials that may leave debris in the oiling circuit ports.
If DTCs P0521, P06DE, and/or P06DD did not set during the engine oil pump failure screening test, review the GDS 2 stored data to isolate a potential oil pump pressure control issue. Each time the engine RPM is raised, the actual oil pressure should move up in a normal pattern. Look for an abnormal pattern that indicates normal pressure is not being achieved. In the following example, there is a normal pressure pattern (Fig. 12, #1), and then abnormal pressure (Fig. 12, #2) followed by failures to achieve normal pressure (Fig. 12, #3), which indicates a failed engine oil pump.
Fig. 12
For more information about reviewing the GDS 2 data as well as part numbers, refer to #PIP5734.
– Thanks to Raymond Haglund
