P0721 2015 GMC Sierra Code - Transmission Output Speed Sensor Performance
Quick Answer
The P0721 diagnostic trouble code (DTC) for a 2015 GMC Sierra indicates an issue with the transmission output speed sensor's performance. Common causes include Faulty transmission output speed sensor, Wiring issues or a poor connection to the sensor, Corrosion or damage to the sensor. 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
- P0721 2015 GMC Sierra indicates Transmission Output Speed Sensor Performance.
- Common causes
- Common causes include Faulty transmission output speed sensor, Wiring issues or a poor connection to the sensor, Corrosion or damage to the sensor.
- 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.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
Code P0721 2015 GMC Sierra Description
The P0721 diagnostic trouble code (DTC) for a 2015 GMC Sierra indicates an issue with the transmission output speed sensor's performance. The transmission output speed sensor is a crucial component that monitors the speed of the output shaft of the transmission. This information is used by the vehicle's engine control module (ECM) to determine shift points and ensure smooth operation of the transmission.
Common Causes of P0721 2015 GMC Sierra
- Faulty transmission output speed sensor
- Wiring issues or a poor connection to the sensor
- Corrosion or damage to the sensor
- ECM software issues
- Mechanical issues within the transmission
Symptoms of P0721 2015 GMC Sierra
- Erratic shifting
- Harsh shifting
- Transmission slipping
- Transmission getting stuck in a single gear
- Illumination of the Check Engine Light
How to Fix P0721 2015 GMC Sierra
- Diagnose the issue by using a scan tool to read the DTC and inspect the transmission output speed sensor and related wiring.
- Replace the faulty transmission output speed sensor if it is determined to be the cause of the issue.
- Check and repair any damaged wiring or connections to ensure proper communication between the sensor and the ECM.
- Clear the DTC from the ECM's memory and test drive the vehicle to ensure the issue has been resolved.
- If the problem persists, further diagnostics may be necessary to identify any underlying mechanical issues within the transmission.
Cost to Fix P0721 2015 GMC Sierra
The typical repair costs for addressing a P0721 code on a 2015 GMC Sierra can vary depending on the specific cause of the issue. Generally, replacing the transmission output speed sensor and addressing any wiring issues can range from $150 to $300 for parts and labor. However, it's important to note that diagnosis time and labor rates at auto repair shops can vary significantly based on factors such as location, vehicle make and model, and engine type. It's advisable to check with local repair shops for a more accurate estimate.
Need more information about the P0721 2015 GMC Sierra code?
Need more information on how to fix the P0721 2015 GMC Sierra code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P0721 2015 GMC Sierra code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about P0721 2015 GMC Sierra Code
No Frequently Asked Questions about P0721 2015 GMC Sierra Code found.
Discuss the causes and fixes for P0721 2015 GMC Sierra OBDII Code
Code P0721 2015 GMC Sierra comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.