AutoCodesGMC – P0521 2017 GMC Sierra

P0521 2017 GMC Sierra Code - Engine Oil Pressure Sensor Performance

Quick Answer

The engine oil pressure sensor changes voltage based on the engine oil pressure. Common causes include Low oil level, Faulty Engine Oil Pressure Sensor, Engine Oil Pressure Sensor harness is open or shorted. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P0521 2017 GMC Sierra indicates Engine Oil Pressure Sensor Performance.
Common causes
Common causes include Low oil level, Faulty Engine Oil Pressure Sensor, Engine Oil Pressure Sensor harness is open or shorted.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
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Code Popularity 493
How popular is this code, among other codes? Low
Table of contents Created and updated by William Orellana on Jun 30, 2022
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Code P0521 2017 GMC Sierra Description

The engine oil pressure sensor changes voltage based on the engine oil pressure. The engine oil pressure sensor is a 3-wire sensor comprising the signal circuit, the low reference circuit, and the 5 V reference circuit. The Engine Control Module (ECM) supplies 5 V to the engine oil pressure sensor via the 5 V reference circuit and provides ground via the low reference circuit. The ECM monitors the signal circuit of the engine oil pressure sensor to determine if the engine oil pressure sensor voltage is within the normal operating range of approximately 1 - 4 V. When the engine oil pressure is high, the engine oil pressure sensor voltage is high, and the ECM senses a high signal voltage. When the engine oil pressure is low, the engine oil pressure sensor voltage is low, and the ECM senses a low signal voltage. The ECM sends the engine oil pressure information to the instrument cluster via serial data. The instrument cluster will illuminate or display the engine oil pressure indicator when the engine oil pressure is low. The Diagnostic Trouble Code (DTC) will be set when the ECM detects that the measured oil pressure is at least 47 kPa (6.8 psi) less than or 50 kPa (7.3 psi) higher than the predicted oil pressure or the engine oil pressure is outside of a calculated working range determined by engine speed and temperature.
OBDII Code P0521 2017 GMC Sierra - Engine Oil Pressure Sensor Performance - AutoCodes.com
P0521 2017 GMC Sierra Code - Engine Oil Pressure Sensor Performance

What are the Possible Causes of the DTC P0521 2017 GMC Sierra?

  • Low oil level
  • Faulty Engine Oil Pressure Sensor
  • Engine Oil Pressure Sensor harness is open or shorted
  • Engine Oil Pressure Sensor circuit poor electrical connection
  • Engine Mechanical Problem
  • Faulty Engine Control Module (ECM)

How to Fix the DTC P0521 2017 GMC Sierra?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

Code Tech Notes

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0521 2017 GMC Sierra code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0521 2017 GMC Sierra code?

Need more information on how to fix the P0521 2017 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0521 2017 GMC Sierra Code

What does the OBDII code P0521 mean on a 2017 GMC Sierra?

P0521 indicates a problem with the engine oil pressure sensor, specifically that its performance is outside the expected range as detected by the powertrain control module (PCM).

What are the common symptoms of code P0521 in a 2017 GMC Sierra?

Symptoms include an illuminated check engine light, erratic or inaccurate oil pressure readings on the gauge, engine ticking noises, and in rare cases, engine performance issues.

What causes the P0521 code to appear on a 2017 GMC Sierra?

Common causes include a faulty engine oil pressure sensor, low or dirty engine oil, a clogged oil filter, wiring or connector issues, or internal engine problems affecting oil pressure.

Can I drive my 2017 GMC Sierra with the P0521 code?

While the vehicle may still be drivable, it’s not recommended to ignore this code as it could indicate low oil pressure, which can lead to severe engine damage.

How do I diagnose code P0521 on a 2017 GMC Sierra?

Start by checking the engine oil level and condition, inspect the oil filter, examine the wiring and connectors for the oil pressure sensor, and test the sensor itself using a multimeter or by comparing readings with a mechanical oil pressure gauge.

How do I fix the P0521 code on a 2017 GMC Sierra?

Common fixes include replacing the engine oil pressure sensor, changing the engine oil and filter, repairing damaged wiring or connectors, or addressing internal engine issues if necessary.

What type of oil should I use to avoid the P0521 code on a 2017 GMC Sierra?

Use the manufacturer-recommended oil type and viscosity, typically SAE 5W-30 for the 2017 GMC Sierra, and ensure it meets GM’s dexos1 specification.

How much does it cost to fix the P0521 code on a 2017 GMC Sierra?

Repair costs vary but typically range from $100 to $300 for parts and labor, depending on whether the issue is a faulty sensor, wiring repair, or an oil change.

Can a clogged oil filter trigger the P0521 code in a 2017 GMC Sierra?

Yes, a clogged oil filter can restrict oil flow, leading to abnormal pressure readings and triggering the P0521 code.

How often should I check my engine oil to prevent the P0521 code on a 2017 GMC Sierra?

It’s recommended to check your engine oil level and condition at least once a month and during every oil change service to prevent issues like P0521.

Discuss the causes and fixes for P0521 2017 GMC Sierra OBDII Code

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