AutoCodes – GMC – P0521 2018 GMC Sierra

P0521 2018 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 2018 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 300

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 30, 2022

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0521 2018 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 2018 GMC Sierra - Engine Oil Pressure Sensor Performance - AutoCodes.com — P0521 2018 GMC Sierra Code - Engine Oil Pressure Sensor Performance

What does this mean?

What are the Possible Causes of the DTC P0521 2018 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 2018 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.

What does this mean?

Code Tech Notes

DTC P0521 can be set if engine oil pressure is outside the calculated engine oil pressure model stored in the engine control module. This can be an indication of mechanical engine issues causing lower than expected engine oil pressure.

There is a factory service bulletin for the following Chevrolet models:
2010 Chevrolet Camaro SS
2007-2010 Chevrolet Avalanche
2007-2010 Chevrolet Silverado
2007-2010 Chevrolet Suburban
2007-2010 Chevrolet Tahoe
2007-2009 Chevrolet Impala
2005-2009 Chevrolet Trailblazer
2007 Chevrolet Monte Carlo
Chevrolet Factory Service Bulletin OBDII Code P0521

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0521 2018 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 2018 GMC Sierra code?

Need more information on how to fix the P0521 2018 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0521 2018 GMC Sierra code diagnosed by a professional: Find a repair shop in your area

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 2018 GMC Sierra Code

1. What are the common symptoms of OBDII code P0521 in a 2018 GMC Sierra?

The common symptoms of code P0521 in a 2018 GMC Sierra include low oil pressure warning light, oil pressure gauge reading zero or fluctuating erratically, and potential engine misfires or stalling.

2. What can cause OBDII code P0521 in a 2018 GMC Sierra?

The most common cause of code P0521 in a 2018 GMC Sierra is a faulty engine oil pressure sensor. Other possible causes include low engine oil level, clogged oil filter, or issues with the oil pump.

3. How can I determine if the engine oil pressure sensor is faulty in my 2018 GMC Sierra?

To determine if the engine oil pressure sensor is faulty, you can perform a visual inspection for any signs of physical damage or oil leaks. Additionally, using a multimeter to test the sensor's electrical resistance can help diagnose the issue.

4. Can I still drive my 2018 GMC Sierra with OBDII code P0521?

It is not recommended to drive your 2018 GMC Sierra with code P0521, as low oil pressure can lead to serious engine damage. It is best to address the issue promptly to avoid potential costly repairs.

5. How can I repair OBDII code P0521 in my 2018 GMC Sierra?

Repairing code P0521 in a 2018 GMC Sierra typically involves replacing the faulty engine oil pressure sensor. Ensure you use a high-quality sensor compatible with your vehicle to resolve the issue effectively.

6. Is it possible for a clogged oil filter to trigger OBDII code P0521 in a 2018 GMC Sierra?

Yes, a clogged oil filter can restrict oil flow and cause low oil pressure, triggering code P0521 in a 2018 GMC Sierra. It is essential to regularly replace the oil filter as part of routine maintenance.

7. Can a low engine oil level cause OBDII code P0521 in a 2018 GMC Sierra?

Yes, a low engine oil level can lead to decreased oil pressure, triggering code P0521 in a 2018 GMC Sierra. Always check and maintain the proper oil level to prevent such issues.

8. Are there any DIY tips for troubleshooting OBDII code P0521 in a 2018 GMC Sierra?

DIY troubleshooting tips for code P0521 include checking the engine oil level, inspecting the oil pressure sensor for damage, and ensuring the oil filter is not clogged. If unsure, consult a professional mechanic for assistance.

9. How important is it to address OBDII code P0521 promptly in a 2018 GMC Sierra?

It is crucial to address code P0521 promptly in a 2018 GMC Sierra to prevent potential engine damage due to low oil pressure. Ignoring the issue can lead to severe consequences and costly repairs down the line.

10. Can faulty wiring or connectors cause OBDII code P0521 in a 2018 GMC Sierra?

Yes, faulty wiring or connectors related to the engine oil pressure sensor can lead to code P0521 in a 2018 GMC Sierra. Ensure all electrical connections are secure and in good condition when diagnosing and repairing the issue.