AutoCodes – GMC – P0521 2015 GMC Sierra

P0521 2015 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 2015 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 315

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
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Code P0521 2015 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 2015 GMC Sierra - Engine Oil Pressure Sensor Performance - AutoCodes.com — P0521 2015 GMC Sierra Code - Engine Oil Pressure Sensor Performance

What does this mean?

What are the Possible Causes of the DTC P0521 2015 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 2015 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 2015 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 2015 GMC Sierra 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 2015 GMC Sierra Code

1. What does the OBDII code P0521 mean on a 2015 GMC Sierra?

P0521 indicates a problem with the engine oil pressure sensor's performance, meaning the sensor is not providing accurate readings or the values are outside the expected range.

2. What are the symptoms of code P0521 on a 2015 GMC Sierra?

Common symptoms include the check engine light turning on, inaccurate oil pressure readings on the gauge, engine performance issues, and in some cases, engine knocking.

3. What causes the P0521 code on a 2015 GMC Sierra?

Potential causes include a faulty oil pressure sensor, low or dirty engine oil, issues with the oil filter, a malfunctioning oil pump, or wiring/connectivity problems.

4. Can I drive my 2015 GMC Sierra with a P0521 code?

Itâ€™s not recommended to drive with this code active, as it could indicate a real oil pressure issue that may damage the engine. Address the problem as soon as possible.

5. How can I fix the P0521 code on my 2015 GMC Sierra?

Start by checking the oil level and quality. If the oil is low or dirty, perform an oil change. Inspect and, if necessary, replace the oil pressure sensor. Check the wiring and connections for damage or corrosion.

6. How much does it cost to repair the P0521 code on a 2015 GMC Sierra?

Replacing the oil pressure sensor typically costs between $100 and $250, including parts and labor. Additional repairs, such as fixing wiring or replacing the oil pump, may increase costs.

7. Can low or dirty oil cause a P0521 code on a 2015 GMC Sierra?

Yes, low or dirty oil can cause this code by affecting oil pressure and sensor readings. Regular oil changes can help prevent this issue.

8. How do I test the oil pressure sensor on a 2015 GMC Sierra?

Use a multimeter to test the sensor's electrical connections and verify the signal voltage. Alternatively, compare the sensorâ€™s readings to a mechanical oil pressure gauge.

9. What happens if I ignore the P0521 code on my 2015 GMC Sierra?

Ignoring this code could lead to engine damage if thereâ€™s a real oil pressure issue or prolonged operation without addressing the problem.

10. Does the P0521 code always mean the oil pressure sensor is bad on a 2015 GMC Sierra?

No, while the sensor is a common culprit, other issues like low oil, a clogged oil filter, or wiring problems can also trigger this code. Proper diagnosis is essential.