OPSSensor

Oil Pressure Sensor (OPS)

Group: Temperature and oil pressure

The oil pressure sensor or switch warns you when engine oil pressure is too low. It is what turns on the red oil can warning light: if it comes on while driving, stop the engine.

Contents

What does the OPS sensor do?

The simplest ones are switches: they close the circuit to ground (turning the light on) when pressure falls below about 0.3 to 0.5 bar (4 to 7 psi). Proportional sensors send a variable voltage or resistance to the instrument cluster or the computer, which then shows the real pressure. On engines with a variable-displacement oil pump, the computer uses the sensor to regulate the pressure.

Where is it located?

Screwed into the engine block, near the oil filter or on the main oil gallery.

Signal type and reference values

  • Switch: 1 wire; continuity to ground with no pressure and open circuit with pressure.
  • Proportional sensor: 3 wires (5 V, ground and signal) or a variable resistance.
  • Approximate pressure with a warm engine: 1 to 2 bar (15 to 30 psi) at idle and 3 to 5 bar (45 to 70 psi) at 3,000 RPM.

Values are a guide only: always check the manufacturer's data for your engine.

Symptoms of a bad OPS sensor

  • Oil light on, or flickering at idle.
  • Oil pressure gauge at zero or erratic.
  • Oil leaking from the sensor itself (very common).
  • Codes P0520 to P0524.

How to test the OPS sensor step by step

  1. First of all, check the oil level on the dipstick.
  2. If the light comes on while driving, do not continue: a real loss of pressure destroys the engine within minutes.
  3. Measure the real pressure with a mechanical gauge in the sensor port and compare it with the manual.
  4. If the real pressure is correct, the fault is in the sensor or the wiring.
  5. Check whether the sensor leaks oil through its connector: it is a common and easy fault to fix.

Trouble codes related to the OPS sensor

Frequently asked questions about the OPS sensor

Can I drive with the oil light on?
No. Stop the engine somewhere safe and check the level. If the level is correct, call a tow truck until the real pressure has been checked.
Can the oil pressure sensor give false alarms?
Yes, a failed switch or a wire shorted to ground turns the light on with no real problem. But never assume that without measuring the pressure with a gauge.

Updated September 25, 2026. Values are a guide only: always confirm them in the service manual for your engine.

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