All codes
P0720Transmission Issues
Output Speed Sensor Circuit Malfunction
Fix P0720 transmission output speed sensor code. Learn how it affects shifting and the speedometer.
What you may notice
Symptoms
- 01Check engine light on
- 02Erratic or harsh shifting
- 03Speedometer inaccurate or not working
- 04Transmission stuck in one gear
- 05Vehicle in limp mode
Where to look first
Common causes
- 01Failed output speed sensor
- 02Damaged wiring or connector
- 03Low or dirty transmission fluid
- 04Connector corrosion
- 05TCM fault (rare)
Step by step
What to check and repair
- 01Check transmission fluid level and condition
- 02Inspect the sensor connector and wiring
- 03Test the sensor's signal output
- 04Replace the output speed sensor if faulty
- 05Scan for additional transmission codes
What Does P0720 Mean?
The P0720 code indicates a problem with the output speed sensor circuit in the automatic transmission. This sensor measures the rotational speed of the transmission output shaft.
How It's Used
The TCM compares output speed with input speed to calculate gear ratios and control shift timing. The output speed signal also frequently feeds the speedometer.
Common Causes
A failed sensor, damaged wiring, or low transmission fluid affecting the sensor are typical causes. Connector corrosion is also common.
Using AI4Car
AI4Car can display live transmission output speed data, helping you confirm whether the sensor signal is present and accurate.