Output Speed Sensor Circuit

What it means

The output speed sensor measures the speed of the transmission output shaft. The computer uses it to time shifts and calculate gear ratio, and on some vehicles for the speedometer too. The computer has detected a fault in this sensor circuit.

Related codes: P0721P0722P0723P0715P0500

Symptoms4

• Check engine light on.
• Erratic or mistimed shifts, or the transmission in limp mode.
• Speedometer dead or erratic on some vehicles.
• Cruise control stops working.

Possible causes5

• Damaged or corroded sensor connector, often in a spot exposed to dirt and water.
• Open or shorted sensor wiring.
• A faulty sensor.
• Metal debris on a magnetic sensor tip.
• A damaged tone ring the sensor reads (less common).

How to diagnose5

1. Watch output speed on a scan tool and compare it with vehicle speed from the wheel speed sensors.
2. Inspect the sensor connector and wiring for corrosion or damage.
3. Measure sensor resistance or supply voltage depending on its type, and compare with the manufacturer specification.
4. Check the sensor signal with an oscilloscope while the wheels turn.
5. Remove the sensor and inspect its tip for debris or damage.

How to fix5

1. Clean the connector and repair damaged wiring.
2. Clean debris from the sensor tip.
3. Replace the output speed sensor.
4. Change the transmission fluid and filter if heavy debris is found, and look for its source.
5. Clear the codes and confirm the speedometer and normal shifting work.

Repair cost

In Saudi riyals; the highlighted part is the expected range for this fault.

The cost is low for a connector repair or sensor cleaning, and higher when the sensor is replaced, especially if it is hard to reach.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions