P0721 2018 Chevrolet Silverado Code - Transmission Output Speed Sensor Performance
Quick Answer
The Output Speed Sensor (OSS) is a hall-effect type sensor. Common causes include Faulty Transmission Output Speed Sensor (OSS), Transmission Output Speed Sensor harness is open or shorted, Transmission Output Speed Sensor circuit poor electrical connection. 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 2018 Chevrolet Silverado indicates Transmission Output Speed Sensor Performance.
- Common causes
- Common causes include Faulty Transmission Output Speed Sensor (OSS), Transmission Output Speed Sensor harness is open or shorted, Transmission Output Speed Sensor circuit poor electrical connection.
- 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.
Code P0721 2018 Chevrolet Silverado Description
The Diagnostic Trouble Code (DTC) will be set when the TCM detects a noisy output speed signal.
What are the Possible Causes of the DTC P0721 2018 Chevrolet Silverado?
- Faulty Transmission Output Speed Sensor (OSS)
- Transmission Output Speed Sensor harness is open or shorted
- Transmission Output Speed Sensor circuit poor electrical connection
- Faulty Transmission Control Module (TCM)
How to Fix the DTC P0721 2018 Chevrolet Silverado?
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 is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0721 2018 Chevrolet Silverado 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.
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Frequently Asked Questions about P0721 2018 Chevrolet Silverado Code
1. What does OBDII code P0721 mean on a 2018 Chevrolet Silverado?
P0721 indicates a transmission output speed sensor performance issue, often related to inconsistent or invalid speed sensor signals.
2. What are common symptoms of code P0721 in a 2018 Chevrolet Silverado?
Symptoms may include erratic shifting, the transmission staying in one gear, the speedometer not working correctly, or the check engine light turning on.
3. What causes code P0721 on a 2018 Chevrolet Silverado?
Common causes include a faulty transmission output speed sensor, damaged wiring or connectors, a malfunctioning transmission control module (TCM), or internal transmission issues.
4. Can I drive my 2018 Chevrolet Silverado with a P0721 code?
Driving with a P0721 code is not recommended, as it can lead to poor transmission performance and potential damage if left unresolved.
5. How do I diagnose code P0721 on my 2018 Chevrolet Silverado?
Diagnosis typically involves scanning for codes, inspecting the output speed sensor and its wiring, checking the sensor's signal with a multimeter, and testing the TCM for faults.
6. How do I fix code P0721 on a 2018 Chevrolet Silverado?
Repairs may include replacing the output speed sensor, repairing or replacing damaged wiring, or, in rare cases, addressing internal transmission issues.
7. How much does it cost to repair a P0721 code on a 2018 Chevrolet Silverado?
Repair costs vary but typically range from $100 to $300 for sensor replacement and labor. More extensive transmission repairs could be higher.
8. Where is the transmission output speed sensor located on a 2018 Chevrolet Silverado?
The transmission output speed sensor is generally located on the transmission housing, near the output shaft.
9. Can a bad output speed sensor cause transmission problems in a 2018 Chevrolet Silverado?
Yes, a faulty speed sensor can cause shifting issues, incorrect speed readings, or even put the transmission into "limp mode."
10. Will clearing the P0721 code solve the issue in my 2018 Chevrolet Silverado?
Clearing the code without addressing the underlying problem is only a temporary fix, and the code is likely to reappear if the issue persists.
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