P0520 Code: Toyota Tacoma (2016-2023) - Causes, Symptoms & Fixes

No recalls found in NHTSA database

Data note: The provided NHTSA data for Toyota Tacoma (2016-2023) shows no owner complaints and no recalls for P0520 in this model/year range. Therefore, there is no complaint frequency to quote from this dataset. P0520 is a recognized OBD-II code meaning “Oil Pressure Sensor/Switch Circuit Malfunction.” In practice, P0520 can be caused by a faulty sensor or by actual oil pressure issues. Treat any oil-pressure-related DTC with caution, as genuine low oil pressure can cause serious engine damage.

CODE MEANING AND SEVERITY

• What P0520 means: The Engine Control Module (ECM/PCM) detected an abnormal condition in the Oil Pressure Sensor/Switch Circuit. This can indicate a faulty sensor, wiring, or connector, or it can indicate actual low or erratic oil pressure from the engine’s lubrication system.
• Severity and risk:
  • Sensor fault scenario: The PCM may illuminate the Malfunction Indicator Lamp (MIL) and set P0520, but engine lubrication may be otherwise normal. Driving may be safe short-term, but you should diagnose and fix to avoid future issues.
  • Actual low oil pressure scenario: If the engine is truly not receiving adequate oil pressure, continuing to run can cause catastrophic engine damage (bearing wear, cam/turbine damage, stuck rings, etc.). Immediate troubleshooting is advised if you observe oil pressure warning, unusual noises, or a hot engine.
• Typical warning cues:
  • MIL on with P0520 present
  • Oil pressure warning light or gauge reading abnormally low
  • Oil pressure fluctuations, especially when hot or at idle
  • Engine noise or weird tapping if oil pressure is actually low

COMMON CAUSES ON TOYOTA TACOMA

Note: The data provided does not contain model-specific failure statistics, so these are general and commonly observed possibilities for P0520 on Toyota Tacomas, not claims of prevalence.

• Faulty oil pressure sensor or switch
  • The most common cause of P0520 on many Toyota engines. Sensor can fail due to age, contaminated oil, or wiring issues.
• Damaged or corroded sensor wiring/connector
  • Chafed insulation, loose ground, or corroded pins can cause incorrect readings or intermittent signals.
• Low oil level or degraded oil
  • Insufficient lubrication can trigger genuine low pressure; always check level and oil condition first.
• Incorrect oil type or degraded oil viscosity
  • Using oil of the wrong viscosity or dirty oil can affect oil pressure readings.
• Oil pump or pickup issues
  • Worn pump internals, a clogged screen, or a restricted oil pickup can reduce actual oil pressure.
• Engine wear and bearing condition
  • Worn crankshaft bearings or other internal wear can reduce actual oil pressure.
• Oil passages or oil gallery restrictions
  • Debris or sludge could restrict flow in older engines.
• Electrical/PCM-related effects
  • Grounding problems or a marginal 5V reference to the sensor can produce fault signals even if oil pressure is fine.
• Intermittent sensor behavior or calibration drift
  • Temperature or electrical noise can cause sporadic readings.

SYMPTOMS

• Electrical / dash indicators
  • Check Engine Light with code P0520
  • Oil pressure warning light on the dash (if equipped)
• Oil pressure readings
  • Low or fluctuating oil pressure reading on the oil pressure gauge (if yourTacoma has an integrated gauge)
• Engine behavior
  • In true low-pressure cases: engine knock or tapping sounds, increased engine heat, reduced power, or rough running
  • In sensor-only cases: engine runs normally, but the MIL remains and P0520 may recur until repaired
• Other indicators
  • Intermittent performance issues or stalling only when hot (less common, but possible if pressure fluctuates)

DIAGNOSTIC STEPS

Important safety note: If you suspect genuine low oil pressure (oil light on, loud engine noises, overheating), stop driving as soon as it’s safe and diagnose or tow the vehicle.

• Step A: Verify basic conditions

  • Check engine oil level with engine off and cooled; top up if low and check for oil leaks.
  • Check oil condition and viscosity; ensure it matches the manufacturer’s specification.
  • Confirm there are no aftermarket oil pumps or abnormal modifications.

• Step B: Read and correlate codes

  • Use a reliable OBD-II scanner to confirm P0520 and look for related codes (P0521, P0522, P0523, etc.).
  • Note freeze-frame data (engine RPM, oil temperature, engine load, etc.) at the time of the fault.

• Step C: Inspect the sensor and wiring

  • Inspect the oil pressure sensor/switch and its connector for signs of damage, oil contamination, or corrosion.
  • Check wiring harness for shorts, frays, or poor connector seating; clean and reconnect as needed.
  • Ensure proper ground and 5V reference to the sensor with a multimeter or scan tool.

• Step D: Verify actual oil pressure (if you have the tools)

  • If you have access to a mechanical oil pressure gauge, perform a live pressure test with the engine hot (oil at operating temperature).
  • Typical hot idle oil pressure ranges vary by engine; consult Toyota service data for exact spec. As a rough guide, hot idle oil pressure is generally lower than at higher RPMs; if your measured pressure is far below spec, suspect a real lubrication issue.
  • Compare readings at idle and at a higher RPM (e.g., 2000-3000 rpm). A healthy system should show a noticeable increase in pressure with RPM.

• Step E: Isolate sensor vs. actual pressure

  • If the mechanical gauge shows normal pressure but the PCM reports abnormal sensor readings, the issue is likely the sensor or its circuits.
  • If the mechanical gauge shows low pressure, the problem is in the oiling system (sensor may still be faulty, but your primary concern is lubrication).

• Step F: Inspect the oiling system for wear or restrictions

  • Check the oil pickup screen for blockage or sludge.
  • Inspect for excessive engine wear (bearing clearance) that can reduce actual oil pressure.
  • Consider replacing the oil pump if there’s evidence of pump wear or failure (see repair costs).

• Step G: Verify no contributing factors

  • Ensure oil leaks or oil consumption aren’t masking issues.
  • Check for any recent work that might have disturbed sensor wiring or connections.

• Step H: Clear codes and recheck

  • After repairs or sensor replacement, clear the codes and test drive to confirm the issue is resolved.

RELATED CODES

• P0521: Oil Pressure Sensor/Switch Range/Performance
• P0522: Oil Pressure Sensor/Switch Circuit Low Input
• P0523: Oil Pressure Sensor/Switch Circuit High Input
• Note: These related codes point to sensor circuit behavior and are useful when diagnosing intermittent readings or sensor faults. If multiple oil-pressure-related codes appear, focus on sensor integrity first, then verify actual oil pressure.

REPAIR OPTIONS AND COSTS (2025 PRICES)

Prices vary by region, shop, and engine configuration (2.7L 4-cylinder vs 3.5L V6). All estimates are ballpark ranges in USD and do not include tax or shop fees.

• A) Oil pressure sensor/switch replacement (sensor only)

  • Parts: roughly $15–$60
  • Labor: roughly $60–$150
  • Total: about $75–$210
  • Notes: Most Tacoma engines use a relatively straightforward sensor install; replacement is a common DIY task if you’re comfortable with basic hand tools.

• B) Sensor replacement + wiring/connector repair

  • Parts: $15–$60
  • Labor: $100–$240 (if harness and connector work is needed)
  • Total: about $150–$300
  • Notes: If wiring is damaged or connector is corroded, add time for diagnosis and repair.

• C) Oil pressure actual issue (oil pump or lubrication system)

  • Parts (oil pump or screen replacement, gaskets, seals): $200–$500
  • Labor: $600–$1,000
  • Total: roughly $800–$1,500
  • Notes: On many Tacomas, the pump is mounted in or near the front cover; replacement can be labor-intensive.

• D) Engine wear or internal lubrication problems (bearings, etc.)

  • Parts: Bearings or related components (if applicable) may require engine work
  • Labor: $1,500–$4,000+ depending on scope
  • Total: $3,000–$7,000+ for a full rebuild or major repair
  • Notes: This is a worst-case scenario. A successful diagnosis that finds genuine engine wear can be expensive.

• E) Additional related work (oil/filter, flush, gasket replacement)

  • Small service items could add $50–$150 depending on parts and shop.

Important cautions:

• If there is any chance of actual low oil pressure, avoid long drives. Low oil pressure can cause severe engine damage in a short period.
• The exact price depends on your location, whether OEM or aftermarket parts are used, and the labor rate of the shop.

DIY vs PROFESSIONAL

• DIY-friendly tasks

  • Replacing the oil pressure sensor/switch yourself is generally doable with basic hand tools and is a common DIY repair.
  • Checking oil level, oil viscosity, and changing the oil/filter are routine maintenance tasks.
  • Inspecting obvious wiring and connector issues can be done with the hood up.

• Tasks better left to a professional

  • Verifying actual oil pressure with a mechanical gauge requires proper adapters and caution.
  • If you suspect a worn oil pump, engine bearing wear, or a clogged pickup screen, a professional inspection is advisable.
  • If multiple related codes appear or there’s uncertainty about diagnosis, a shop with Toyota-specific diagnostic experience is recommended.

• How to approach as a DIYer

  • Gather the right tools (DC voltmeter/multimeter, diagnostic scanner, basic hand tools, oil pressure gauge if you have one).
  • Work in a safe environment; ensure the engine is cool before touching hot components.
  • Document wiring connections before disassembly so you can reattach correctly.
  • If you replace the sensor and the code persists, recheck wiring and consider a professional inspection.

PREVENTION

• Regular oil maintenance
  • Follow Toyota’s recommended service intervals for oil change frequency and use the correct viscosity/grade for your engine.
  • Use OEM-spec or high-quality synthetic oil as recommended for your Tacoma engine.
• Monitor oil level and quality
  • Check oil level regularly and maintain it within the recommended range.
  • Change the oil filter at recommended intervals to prevent contamination and buildup that can affect lubrication.
• Keep the oil system clean
  • Avoid long-term use of poor-quality oil or adulterated oils.
  • If you’ve had previous oil leaks or sludge buildup, consider an engine flush or professional cleaning as advised by a technician.
• Electrical connections
  • Periodically inspect the oil-pressure sensor wiring and connectors for corrosion or damage, especially after off-road use or exposure to moisture.
• Proactive diagnosis
  • If you see the MIL or P0520 triggers repeatedly, perform a full diagnostic check early to prevent potential engine damage.

Recalls

• No recalls found in NHTSA database

Data limitations

• The supplied dataset indicates no NHTSA complaints for this specific issue and no recalls for this model/year range. Therefore, the diagnostic guide relies on standard automotive knowledge and general best practices rather than model/year-specific statistical data. If you have access to dealer service bulletins (TSBs) or new data, those should be consulted to refine diagnostics and repair steps. Always cross-check with Toyota service literature for exact torque specs, sensor testing procedures, and oil-pressure specifications for your particular Tacoma engine variant.