P0520 on Subaru
Engine Oil Pressure Sensor/Switch Circuit Malfunction
P0520 on Subaru vehicles indicates engine oil pressure sensor/switch circuit malfunction. Au7o has documented this code across 1 Subaru model — most commonly on WRX STI. This code indicates a general electrical fault in the circuit for the engine oil pressure sensor or switch. The computer monitors this circuit to know your oil pressure, and it has detected a signal that is missing, shorted, or otherwise out of the expected electrical range. This is typically a wiring or sensor problem rather than an actual loss of oil pressure, but because oil pressure is critical to engine life, it should never be ignored until confirmed. If oil pressure truly is low, serious engine damage can result. Typical repair costs on Subaru range from $200 to $3,500, depending on the specific model and root cause.
Common Causes of P0520
- •Faulty oil pressure sensor or switch
- •Damaged, corroded, or loose wiring/connector at the sensor
- •Open or short in the sensor circuit wiring
- •Poor ground connection
- •Low engine oil level or genuinely low oil pressure
- •Failed PCM/ECM (less common)
P0520 on Subaru by Model
Subaru WRX STI(1 issue)
- Oil Starvation During Hard Cornering (EJ257 Boxer Engine)2004-2021
The EJ257 boxer engine uses a shallow oil pan design that is prone to oil starvation during sustained high-G cornering, particularly on track days or aggressive canyon driving. The flat-four layout means oil sloshes away from the pickup tube during lateral loading, starving rod and main bearings of lubrication. This is a leading cause of spun rod bearings and catastrophic engine failure on STIs used for motorsport or spirited driving.
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What does P0520 mean on Subaru?▼
P0520 stands for "Engine Oil Pressure Sensor/Switch Circuit Malfunction." This code indicates a general electrical fault in the circuit for the engine oil pressure sensor or switch. The computer monitors this circuit to know your oil pressure, and it has detected a signal that is missing, shorted, or otherwise out of the expected electrical range. This is typically a wiring or sensor problem rather than an actual loss of oil pressure, but because oil pressure is critical to engine life, it should never be ignored until confirmed. If oil pressure truly is low, serious engine damage can result. On Subaru specifically, this code is documented across 1 model.
What causes P0520 on Subaru vehicles?▼
Common causes on Subaru: Faulty oil pressure sensor or switch, Damaged, corroded, or loose wiring/connector at the sensor, Open or short in the sensor circuit wiring, Poor ground connection, Low engine oil level or genuinely low oil pressure. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0520 on a Subaru?▼
Repair costs on Subaru range from $200 to $3,500, depending on the specific model and root cause.
Which Subaru models have P0520 documented?▼
Au7o has documented P0520 on 1 Subaru model: WRX STI.