P0720 code meaning
Output Shaft Speed Sensor Circuit
Powertrain system Generic code P07xx codes Check engine light
What P0720 means
The output shaft speed sensor (Hall or inductive) reports the speed of the transmission output; it gives the gear ratio together with input speed and on many vehicles also the road speed for speedometer and cruise control. P0720 is the general circuit code. Ford also uses it for 'no signal': while engine and turbine speed show the vehicle moving, the sensor reports under 100–200 rpm for 5–30 s; ZF's 6HP26 in Ford vehicles flags an open or short after 0.6 s. Subaru-based systems (Saab 9-2X) flag an impossible 255 km/h or 0 km/h while driving and light the MIL after two trips, substituting the other sensor. GM does not use P0720 but P0722. Speedometer and cruise control may fail, often with a vehicle speed code as well.
P0720 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0720
- Speedometer drops out or jumps
- Warning lamp, limp mode or fixed gear
- Harsh shifts, cruise control not working
Common causes of P0720
- Most likelySpeed sensor faulty (Hall IC or coil open or shorted)
- Most likelyConnector or harness corroded, chafed or loose pins (with internal sensors also the pass-through connector)
- PossibleMetal debris on the sensor magnet or damaged reluctor wheel
- Less likelyTransmission module or its sensor supply faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Output speed sensorSensor wiringTransmission control module
What each part of P0720 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 7 | Area: transmission. |
| 20 | The exact fault in that area. |
What to do next
- Note P0720 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0720
What does P0720 mean?
P0720 means "Output Shaft Speed Sensor Circuit". The output shaft speed sensor (Hall or inductive) reports the speed of the transmission output; it gives the gear ratio together with input speed and on many vehicles also the road speed for speedometer and cruise control. It is a generic code, so it means the same on every make.
Is it safe to drive with P0720?
Drive gently and only to a workshop. With P0720 the car can go into limp mode (reduced power) to protect itself.
Will P0720 fail an emissions test?
Yes, it can. P0720 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0720 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P0720 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.