Output Speed Sensor Circuit No Signal

What it means

The computer has received no signal from the output speed sensor while the vehicle is moving, which it usually confirms against wheel speed or input speed. A complete loss of signal usually points to an unplugged connector, a broken wire or a completely failed sensor.

Related codes: P0720P0721P0723P0717P0500

Symptoms4

• Check engine light on.
• Speedometer dead on vehicles that use this sensor.
• Transmission stuck in one gear or shifting abnormally.
• Cruise control not working, possibly with vehicle speed codes stored.

Possible causes5

• Sensor connector unplugged, broken or corroded.
• Open sensor wiring.
• Complete sensor failure.
• Lost supply voltage on sensor types that need one.
• A fault in the transmission control module (rare).

How to diagnose5

1. Confirm output speed reads zero while moving while wheel speed is normal.
2. Inspect the connector and wiring for disconnection, breaks or corrosion.
3. Measure sensor resistance, or its supply and ground, depending on type.
4. Check wiring continuity between the sensor and the module.
5. Check the sensor signal directly with an oscilloscope while turning the wheels.

How to fix5

1. Reconnect the connector or replace it.
2. Repair the broken wire.
3. Replace the output speed sensor.
4. Repair the supply circuit if it is open.
5. Clear the codes and confirm the speedometer and normal shifting work.

The cost is low for reconnecting a connector or repairing a wire, and higher when the sensor is replaced.

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