P0523 Engine oil pressure sensor or switch circuit reading too high in voltage

Engine Oil Pressure Sensor/Switch High Input

P0523 in short

P0523 means the computer sees a too-high voltage from the engine oil pressure sensor or switch circuit. A faulty sensor, a damp or damaged connector, or wiring trouble is most likely, but real oil pressure problems can set it too. Get it checked soon, and stop if the oil warning light is on.

The oil pressure sensor turns oil pressure into a voltage signal for the computer and the gauge. P0523 sets when that voltage is higher than the computer expects, which can mean the circuit is faulty or that the sensor is reporting an actual pressure problem.

On many vehicles the cause is the sensor or its connector. Ford says liquid in the sensor connector on 2016 and 2017 F-150 trucks with the 3.5L GTDI or 5.0L engine can set P0521 to P0524 and cause a low or no oil pressure reading, and GM investigated erratic oil pressure gauge readings with P0522 and P0523 on its 2004 trucks and SUVs.

Because the sensor can also be reporting a real problem, confirm the pressure with a manual gauge before assuming the sensor is bad.

Most likely causes

  1. Faulty oil pressure sensor or contaminated connector

    Supported by vehicle data
    Why it ranks here
    Ford SSM 46526 ties P0521 to P0524 on 2016-2017 F-150 3.5L GTDI and 5.0L engines to liquid in the oil pressure sensor connector, and PartsAvatar lists a defective switch first. GM also investigated this code on 2004 trucks and SUVs.
    What would change this
    Rises if the connector is wet or corroded, or a manual gauge shows normal pressure while the sensor reads wrong. Falls if the gauge confirms low pressure.

  2. Damaged, corroded or shorted wiring

    Common general cause
    Why it ranks here
    PartsAvatar lists damaged, burnt, shorted or corroded wiring and connectors as a common cause.
    What would change this
    Rises if wiring shows damage or the signal reads high with the sensor unplugged. Falls if the harness tests fine.

  3. Actual oil pressure problem (wrong oil, wear, pump or relief valve)

    Possible — needs testing
    Why it ranks here
    PartsAvatar says the code can mean an actual oil pressure condition, and lists wrong oil, neglected changes, wear, and oil pump, relief valve or chain tensioner failure.
    What would change this
    Rises if a manual gauge reads outside specification at idle, 1,200 and 2,500 rpm. Falls if the gauge reads normal.

  4. Engine computer fault

    Possible — needs testing
    Why it ranks here
    PartsAvatar lists a computer failure as a cause, but it is rare compared with the sensor and wiring.
    What would change this
    Rises only after sensor, wiring and real pressure are all ruled out.
    How to test the engine control module (ecm / pcm)

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. With the engine off, cool and level, check the oil level and condition, and note whether the oil pressure light or gauge looks wrong.

    Low risk

  2. Inspect the oil pressure sensor connector and wiring for moisture, corrosion, damaged seals or rubbing, and check for related bulletins.

    Low risk

  3. Have a shop measure oil pressure with a manual gauge at idle, 1,200 rpm and 2,500 rpm, and compare it with the specification.

    Best left to a shopTool: manual oil pressure gauge

    Warning:The gauge connects at the oil pressure port on a hot engine with hot oil. Let a shop do it.

Symptoms

  • Check engine light on
  • Oil pressure gauge reads wrong, high or zero
  • Oil pressure warning light on Gets more serious: stop and have it checked.
  • Ticking or knocking from the engine Gets more serious: stop and have it checked.

How to fix

  1. With the engine off, cool and level, check the oil level and top up with the grade in the owner's manual if it is low.

Parts and cost context

  • Engine control module (ECM / PCM):Test the sensor, connector and real oil pressure before replacing anything, and the computer is rarely the cause. Labor varies; get a quote.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

Ford

  • 2016–2017 · F-150 · 3.5L GTDI, 5.0L V8

    Supported by vehicle data

    Ford bulletin SSM 46526 ties low or no oil pressure indication with P0521 to P0524 on 2016-2017 F-150 trucks with the 3.5L GTDI or 5.0L engine to liquid in the sensor connector. Whether it is still current is not verified.

  • SSM 46526Status unverified

    Low or no oil pressure indication with P0521-P0524, 3.5L GTDI and 5.0L

    2016–2017f-150 · NHTSA 10109014

    Liquid contamination in the oil pressure sensor connector is the suspected cause. Replace the sensor if contamination is found, repair damaged connector seals at C1657, and do not use dielectric grease in the sensor connector.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Chevrolet

  • 2004 · Tahoe

    Supported by vehicle data

    GM investigated and issued bulletins for erratic oil pressure gauge readings with P0522 and P0523 on 2004 GMT800 trucks and SUVs, including the Tahoe, Suburban and Silverado. Whether they are still current is not verified.

  • 040604065Status unverified

    Engineering investigation EI 04073: high, low or erratic oil pressure gauge reading with P0522 and/or P0523

    2004tahoe, suburban, avalanche, silverado-1500, express · NHTSA 10011049

    GM investigated erratic oil pressure gauge readings with these codes on 2004 trucks and SUVs. The NHTSA summary does not give the repair.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • 01972Status unverified

    Erratic oil pressure with P0522 or P0523

    2004tahoe, suburban, avalanche, silverado-1500, express · NHTSA 10007581

    GM bulletin for erratic oil pressure with these codes on 2004 GMT610 and GMT800 vehicles. The NHTSA summary does not give the repair.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • P0521Engine oil pressure sensor or switch range/performance

    Shares causes Supported by vehicle data

    Ford SSM 46526 covers P0521 to P0524 together when liquid in the oil pressure sensor connector gives a bad reading.

  • P0524Engine oil pressure too low

    Shares causes Supported by vehicle data

    P0524 is the low-pressure code in the same family, and Ford SSM 46526 covers it with P0523. Treat it as urgent.

All Vehicle speed, idle control and engine electrical codes

P0523 questions

Does P0523 mean my oil pressure is high?

Not necessarily. It means the sensor voltage is high, which is more often a sensor or wiring fault than real high pressure. A manual gauge test settles it.

Can I keep driving with P0523?

Only if the oil level is right, the oil warning light is off and the engine sounds normal, and get it checked soon. Stop if the oil light comes on.

Sources and review

  1. P0523 OBD Code: Engine Oil Pressure Sensor/Switch High Input — PartsAvatar
  2. Ford SSM 46526: low or no oil pressure indication with P0521-P0524 on 2016-2017 F-150 3.5L GTDI and 5.0L (liquid in the sensor connector) — Ford Motor Company / NHTSA
  3. GM engineering investigation EI 04073: high, low or erratic oil pressure gauge reading setting P0522 and/or P0523 (2004 GMT800 trucks and SUVs) — General Motors / NHTSA
  4. GM 01972: erratic oil pressure with P0522 or P0523 on GMT610/GMT800 trucks and SUVs — General Motors / NHTSA
Last reviewed
Written by
Saurabh K.
Editorial review
Pending
Technician review
Technician review pending

This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error

My Car

Pick your car and code pages will point out notes and bulletins for it. Saved only in this browser.

Fill this in from your VIN

Used once to identify your engine; not stored.