P0521 on Buick
Engine Oil Pressure Sensor/Switch Range/Performance
P0521 on Buick vehicles indicates engine oil pressure sensor/switch range/performance. Au7o has documented this code across 1 Buick model — most commonly on Encore. This code indicates the engine oil pressure sensor or switch is sending a reading that is implausible or out of its normal operating range — for example, the value doesn't match what the engine's speed and conditions should produce. Unlike a simple circuit fault, this means the signal is present but doesn't make sense (range/performance). It can be caused by a failing sensor, wiring issues, or by genuinely abnormal oil pressure. Because oil pressure protects the engine, a true low-pressure reading should be confirmed and taken seriously.
Common Causes of P0521
- •Faulty or worn oil pressure sensor/switch
- •Low engine oil level or actual abnormal oil pressure
- •Wiring or connector corrosion/damage at the sensor
- •Sludge or debris affecting the sensor reading
- •Use of incorrect oil viscosity
- •Failing oil pump
- •Poor electrical ground
P0521 on Buick by Model
Buick Encore(1 issue)
- Encore GX (2020+) Three-Cylinder Turbo Stalling and Low-Oil-Pressure ECM Recall2020-2023
The second-generation Encore GX uses 1.2L and 1.3L turbocharged three-cylinder engines and has drawn complaints of reduced engine power, stalling, and lurching. GM issued a recall in which the engine control module (ECM) could fail to clear the permanent status of DTC P0521 (engine oil pressure sensor performance), masking a real low-oil-pressure condition; the remedy is an ECM reprogram. Owners also report elevated oil consumption on these small turbo engines.
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What does P0521 mean on Buick?▼
P0521 stands for "Engine Oil Pressure Sensor/Switch Range/Performance." This code indicates the engine oil pressure sensor or switch is sending a reading that is implausible or out of its normal operating range — for example, the value doesn't match what the engine's speed and conditions should produce. Unlike a simple circuit fault, this means the signal is present but doesn't make sense (range/performance). It can be caused by a failing sensor, wiring issues, or by genuinely abnormal oil pressure. Because oil pressure protects the engine, a true low-pressure reading should be confirmed and taken seriously. On Buick specifically, this code is documented across 1 model.
What causes P0521 on Buick vehicles?▼
Common causes on Buick: Faulty or worn oil pressure sensor/switch, Low engine oil level or actual abnormal oil pressure, Wiring or connector corrosion/damage at the sensor, Sludge or debris affecting the sensor reading, Use of incorrect oil viscosity. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0521 on a Buick?▼
Repair costs vary widely depending on the root cause and specific Buick model.
Which Buick models have P0521 documented?▼
Au7o has documented P0521 on 1 Buick model: Encore.