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SPN 1566high severity✨ AI-generated

Engine Oil Pressure Sensor Circuit Low

Indicates a low voltage signal from the engine oil pressure sensor.

Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.

What it means (plain English)

The engine oil pressure sensor is sending a low voltage signal, meaning the oil pressure is either genuinely low or the circuit is faulty.

What the computer is actually seeing

The engine control unit (ECU) sees a voltage from the oil pressure sensor below the expected range, generally less than 0.5 volts when it should be around 1-4 volts with the engine running.

What a healthy reading looks like

Expected oil pressure sensor voltage should be between 1 and 4 volts at normal operating temperatures.

Guided diagnostic — the DiagCoach way

Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.

  1. 11. Check engine oil level – should be within the safe range on the dipstick. Decision: If low, refill oil and retest. If okay, continue.
  2. 22. Inspect wiring harness and connectors to the oil pressure sensor for wear or damage. Decision: If damaged, repair or replace wiring. If good, continue.
  3. 33. Disconnect the oil pressure sensor and measure resistance across the terminals. Expected resistance should be close to zero ohms for a good sensor. Decision: If resistance is too high or infinite, replace the sensor. If resistance is okay, continue.
  4. 44. Test for proper voltage at the sensor connector with engine running. Expected voltage should be within 1-4 volts. Decision: If voltage is low, check wiring and ECU. If voltage is normal, replace the oil pressure sensor.

Common causes

  • Faulty oil pressure sensor
  • Oil pressure too low due to leaks or low oil level
  • Wiring issues such as frayed or shorted wires
  • Faulty ECU or connector issues

Typical repair cost

$$

Related codes

Frequently asked questions

Is it safe to drive with this code?

No, it's not safe; low oil pressure can cause severe engine damage.

Will this code come back after resetting?

It can come back if the underlying issue isn't fixed, such as a leak or faulty sensor.

Why might it pair with SPN 1565?

SPN 1565 indicates an oil pressure sensor circuit high fault, which can occur if there's a fault in the sensor or wiring.

Working a real vehicle right now?

Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.

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