P0720: Output Speed Sensor Circuit Malfunction
Can you still drive? Drive with caution. The speedometer may be inaccurate and the transmission may shift unpredictably. Avoid highway driving until repaired.
What Does P0720 Mean?
Code P0720 indicates the output speed sensor (also called the vehicle speed sensor on the transmission) is providing an erratic or invalid signal. This sensor measures the speed of the transmission output shaft, which the PCM uses for shift scheduling, speedometer readings, and cruise control operation. A faulty signal disrupts all of these functions.
Need to read your codes?
An OBD-II scanner lets you read and clear diagnostic trouble codes from your vehicle's computer. Most scanners work with any car made after 1996.
Browse OBD-II Scanners on AmazonCommon Causes
- Failed output speed sensor
- Damaged sensor wiring or connector
- Contaminated transmission fluid
- Damaged gear on output shaft
- Faulty PCM/TCM
Symptoms
- Check engine light on
- Erratic speedometer readings
- Harsh or delayed shifting
- Cruise control not working
- Transmission slipping or hunting between gears
Diagnostic Steps
- 1Read freeze frame data and note speed and gear data
- 2Check transmission fluid level and condition
- 3Inspect output speed sensor wiring and connector
- 4Test sensor resistance with multimeter against specifications
- 5Monitor output speed sensor data with scan tool during test drive
- 6Compare output speed to input speed for correct gear ratios
Recommended Parts & Tools
output speed sensor
transmission fluid
OBD-II scan tool
Estimated Repair Cost
| Type | Estimated Cost |
|---|---|
| Total Repair Cost Range | $75 - $400 |
Get a Personalized AI Diagnostic Report
Get a detailed AI diagnosis for code P0720 specific to your vehicle. Includes step-by-step repair instructions, exact parts needed, and a cost breakdown tailored to your make and model.
Chat with AI About P0720Commonly Affected Vehicles
Related Recalls
Frequently Asked Questions
Can a bad output speed sensor cause shifting problems?
Absolutely. The TCM relies on the output speed sensor to determine when to shift. Without accurate data, shifts will be harsh, delayed, or occur at the wrong time.
Is the output speed sensor the same as the vehicle speed sensor?
On many vehicles, yes. The output speed sensor on the transmission provides the vehicle speed signal used for the speedometer, cruise control, and shift scheduling.
Community Fix Reports
Community reports are user-submitted and not verified by Auto AI Buddy. Results may vary.
Related Codes
Affiliate Disclosure: This page contains affiliate links. If you purchase products through these links, we may earn a small commission at no additional cost to you. This helps us maintain this free resource. We only recommend products we believe will help you diagnose and repair your vehicle. Prices shown are estimates and may vary.