P0523 Generic (SAE) Basic entry

Engine Oil Pressure Sensor/Switch High Voltage

Updated 2026-10-02 · Vehicle speed, idle control & auxiliary inputs

Severity

High

Typical repair cost

40 – 350 EUR

System

Powertrain

What it means

P0523 is stored when the engine control module measures a voltage in the Engine Oil Pressure Sensor/Switch circuit above the expected maximum, typically because the signal wire is shorted to battery voltage or the circuit is open and pulled up internally.

This entry is compiled automatically from the standard definition and typical diagnostic practice for this type of fault. A detailed, reviewed article is in preparation.

Advertisement728 × 90

Symptoms

Check engine light on
Idle too high, too low or hunting
Stalling when coming to a stop
Speedometer or cruise control not working in some cases

Common causes

Damaged, chafed or corroded wiring in the Engine Oil Pressure Sensor/Switch circuit
Corroded, loose or water-damaged connector terminals
Failed Engine Oil Pressure Sensor/Switch component (sensor, solenoid or actuator)
Poor ground connection for the module or component
Faulty control module driver (rare, confirm all else first)

How to diagnose

Read freeze frame data and note when the code set (cold start, under load, after rain)
Inspect the Engine Oil Pressure Sensor/Switch connector for bent pins, corrosion and water; wiggle the harness with the engine running and watch live data
Measure supply voltage and ground at the connector with the key on
Check the signal wire for shorts to ground or battery and for continuity to the control module
Test or substitute the Engine Oil Pressure Sensor/Switch only after wiring and connectors are confirmed good
Clear the code and complete a drive cycle to confirm the repair

Frequently asked questions

Can I keep driving with P0523?

Not for long. This code can lead to expensive follow-up damage or affects safety systems; have it checked as soon as possible.

Will clearing P0523 fix it?

No. Clearing only erases the stored code; it returns as soon as the monitor runs again unless the cause is repaired.