The P0721: Output Speed Sensor Range/Performance indicates that there is an issue with the performance or range of the output speed sensor, which monitors the rotational speed of the transmission output shaft. A malfunction in this sensor can lead to shifting problems or erratic transmission behavior. The issue may arise from a faulty sensor, wiring problems, or connection issues.
P0721 – Quick Overview
| Code | Information |
|---|---|
| Meaning | P0721: Output Speed Sensor Range/Performance |
| Is it serious? | Yes, as incorrect speed readings can cause improper shifting and transmission performance issues. |
| Possible causes | – Faulty output speed sensor – Sensor range or performance issues – Wiring or connector problems |
| How to diagnose? | – Test the output speed sensor for range and performance – Inspect wiring and connectors – Replace sensor if performance is out of range |
P0721 Meaning
The P0721 code is triggered when the transmission control module (TCM) detects an issue with the output speed sensor’s range or performance. This sensor measures the speed of the transmission output shaft, and an incorrect signal can affect the shifting process and overall transmission function.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to check for additional transmission-related codes that may provide further insight into the output speed sensor issue. | OBD-II Scanner |
| Test the Output Speed Sensor for Range and Performance | Use a multimeter or diagnostic tool to test the output speed sensor’s signal and performance. Compare the readings to manufacturer specifications to ensure the sensor is operating within the correct range. | Multimeter, Diagnostic Tool |
| Inspect Wiring and Connectors | Visually inspect the wiring and connectors related to the output speed sensor for any signs of damage, corrosion, or loose connections. | Flashlight, Multimeter |
| Check Sensor Alignment | Ensure the output speed sensor is properly aligned and securely mounted, as misalignment can cause incorrect readings. | Basic Tools |
| Replace the Sensor if Necessary | If the output speed sensor is faulty or not performing within the expected range, replace it with a new one to restore proper transmission function. | Replacement Parts, Standard Tools |
| Clear Code and Retest | After repairs, clear the P0721 code using an OBD-II scanner and take the vehicle for a test drive to ensure the issue is resolved. | OBD-II Scanner |
| Recheck for Codes | After the test drive, re-scan the vehicle to ensure the P0721 code has not returned. | OBD-II Scanner |
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