Fault code P0523 – engine oil pressure sensor/switch circuit high voltage

Fault code P0523 is called “Engine Oil Pressure Sensor/Switch Circuit High Voltage” but in different programs it may be called differently. This fault designation applies to all vehicles equipped with OBD-II.

Technical description and explained code P0523

OBD-II trouble code P0523 is a general code that is defined as “high engine oil pressure sensor or switch circuit signal level”. It is set when the powertrain control module (PCM) detects an unexpected oil pressure value. It may also be set when there is a fault in the oil pressure switch or its control circuit.

Fault code P0523 – engine oil pressure sensor/switch circuit high voltage

The oil pressure switch is a simple pressure switch to which the PCM supplies a reference voltage. The pressure sensing mechanism in the switch is in direct contact with the oil circulating in the engine.

Changes in oil pressure cause the oil pressure switch resistance to either decrease or increase. The PCM understands these resistance changes as the actual oil pressure at that moment at that engine speed.

The PCM is programmed to recognize a range of signal voltages that are compared to the oil pressure reference range for that vehicle. Therefore, when the PCM detects an abnormally high signal voltage, code P0523 is set.

The warning light on the instrument panel may also illuminate. This, in turn, complements the error code and may indicate abnormal oil pressure.

Some vehicles use more than one oil pressure switch. One gauge is used to indicate high or normal pressure and another to indicate low pressure.

Symptoms of vehicle malfunctions

The main signal that an error P0523 has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.

It can also be warning signs such as:

  1. Check engine control lamp on the control panel will light up (the code will be recorded in the memory as a fault).
  2. Oil pressure check lamp illuminated.
  3. When the engine is running, various mechanical noises may occur, which change as the speed changes.
  4. Ignition skips in the engine cylinders are possible, especially if the problem is related to low oil pressure.

Error P0523 related to oil pressure is considered very serious, so it is recommended to eliminate this problem as soon as possible. For example, if the oil pressure is too low, it may cause the crankshaft and connecting rod bearings.

Factors that can cause this error code

The error code P0523 can mean that one or more of the following problems have occurred:

  • Engine oil pressure sensor is defective.
  • Excessive resistance in oil pressure sensor circuit.
  • Damaged, burned, shorted, or corroded wiring.
  • Use of unsuitable engine oil.
  • Poor maintenance, such as irregular oil and oil filter changes.
  • Excessive mechanical wear and tear on the engine.
  • Mechanical failure of internal engine components such as oil pump, oil pressure relief valve. Also, possibly tensioners or timing chain guides.
  • Sometimes the cause is a faulty PCM module.

How to fix or reset OBD-2 code P0523

Some suggested steps for troubleshooting and fix the error code P0523:

  1. Read all data and stored error codes, using an OBD-II scan tool.
  2. Clear the codes and check if error code P0523 appears again.
  3. Check the level and condition of the engine oil. If necessary, replace the oil along with the filter.
  4. Inspect the engine oil pressure sensor and associated wiring.
  5. Check the sensor with a digital multimeter, and replace it if necessary.
  6. Pay attention to mechanical wear and tear on the engine. Physically check the oil pressure with a mechanical oil pressure gauge.

Diagnose and repair of problems

Check that the oil level is at the proper level, that it is not diluted with fuel or coolant, and that it is not of a thick, tarry consistency. If necessary, add or change oil before proceeding with further diagnosis.

Perform a thorough visual inspection of the wiring to look for damaged, burned, disconnected, shorted, or corroded wires and connectors. If necessary, repair, clear code P0523 and re-scan the system to see if the code returns.

Check the wiring with a multimeter

After no visible damage is found, check the resistance, ground, and reference voltage. Compare all readings with those in the manual. If necessary, replace the wiring to ensure that all readings are in accordance with the manufacturer’s specifications.

Remember to disconnect the oil pressure switch from the PCM while checking resistance and continuity to prevent damage to the controller. The oil pressure switch should also be checked, as it is part of the control circuit.

Checking the oil pressure

You need to make sure that the oil pressure is within the range specified by the manufacturer, this can be done by attaching a pressure gauge to the engine. Using a scanner is not recommended because the scanner uses the same information as the PCM.

The PCM and the scan tool may indicate an oil pressure condition that is based on incorrect data.

It may take a few seconds for the gauge to record a reading, but after about ten seconds it should stabilize. Record the reading and compare it to the value in the manual.

Allow the engine to warm up, watching the gauge reading. As the engine warms up, there may be a slight drop in pressure indicated by the pressure gauge. But oil pressure should not drop below the minimum specified value when the engine is at operating temperature.

Oil pressure readings that fall below the acceptable lower limits indicate excessive wear or other mechanical problems inside the engine. In this case, simply replacing the oil pressure switch will not solve the problem of error P0523.

On which vehicles does this problem occur most frequently

Fault code P0523 can occur on different vehicles but there are statistics on which brands this occurs most often. Here is a list of some of them:

  • Cadillac (CTS, Escalade, SRX)
  • Chevrolet (Impala, Silverado, Tahoe)
  • Datsun (on-DO)
  • Dodge
  • GMC (Yukon)
  • Honda (Accord, Civic, Pilot)
  • Jeep (Grand Cherokee)
  • LADA (Granta, Kalina, Priora, Vesta)

Fault code P0523 can sometimes be found with other errors. The most common are the following: P0017, P0202, P0300, P0305, P0308, P0327, P0332, P0352, P0443, P0520, P0521, P0522, P0524, P1492, P1499, P1626.


Rate article
AutoNevod | Technical description of OBD-2 car faults and their solution
Add a comment