P0720 — Output Speed Sensor Circuit Malfunction
Drive with caution — fix soon.
What P0720 means
This code means the transmission control computer detected a problem with the output (vehicle) speed sensor circuit, which measures how fast the transmission output shaft is spinning. It's frequently caused by a failed sensor, damaged wiring, or a poor connector, and sometimes by debris on the sensor. Repairs are often straightforward, typically replacing the sensor or fixing the wiring.
Common symptoms
- Check Engine light is on
- Speedometer reads erratically or not at all
- Harsh, erratic, or delayed shifting
- Transmission stuck in one gear or in limp mode
- Cruise control may stop working
Common causes
- Faulty output (vehicle) speed sensor
- Damaged or corroded wiring to the sensor
- Loose or dirty electrical connector
- Metal debris or contamination on the sensor tip
- Internal transmission fault affecting the signal
Typical repair cost
$100 – $500
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0720 code?
Short trips are often possible, but be careful. Without a correct speed signal the transmission may shift roughly or go into limp mode, and your speedometer may be unreliable, so get it repaired soon.
How much does it cost to fix a P0720?
It's usually one of the more affordable transmission codes. Replacing the speed sensor and any wiring repair typically runs about $100 to $500, depending on the sensor's location and labor.
Is a P0720 code serious?
It's moderately serious. It often comes down to a simple sensor, but the faulty signal can cause erratic shifting and limp mode, so it shouldn't be left unaddressed.
Why is my speedometer affected by a P0720?
On many vehicles the output speed sensor also feeds the speedometer and cruise control, so when it fails you may see a jumpy or dead speedometer along with the shifting problems.