P0720
Output Speed Sensor Circuit Malfunction
high
i Description
The transmission output speed sensor circuit has a malfunction. This sensor measures the rotational speed of the transmission output shaft, which indicates vehicle speed and is used for shift control.
? Common Causes
- Faulty output speed sensor
- Damaged wiring or connector
- Contaminated transmission fluid
- Damaged sensor drive gear
! Symptoms
- Check engine light
- Speedometer malfunction
- Harsh or incorrect shifting
- Transmission may enter limp mode
- Cruise control inoperative
# Diagnostic Steps
- Test output speed sensor resistance and signal
- Inspect wiring and connector
- Check transmission fluid condition
- Inspect sensor drive gear for damage
- Compare reading to VSS (if separate)
⚙ Typical Fix
Replace the output speed sensor.
Parts Needed
Output speed sensor, Transmission fluid
Estimated Cost
$100-$400
↔ Related Codes
Q Frequently Asked Questions
Shifting will be affected and the speedometer may not work. Drive carefully at low speeds to a mechanic.
Output speed sensor: $20-$80. Labour: $80-$200. Usually external to the transmission, making it easier to access than the input sensor.
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