Input/Turbine Speed Sensor A Circuit No Signal

What it means

The computer has received no signal at all from the input speed sensor while the engine is running and the vehicle is moving. A complete loss of signal usually points to an open circuit, an unplugged connector or a completely failed sensor, so the computer uses limp mode.

Related codes: P0715P0716P0718P0722P0700

Symptoms4

• Check engine light on.
• Transmission stuck in one gear with weak acceleration.
• Very harsh engagement when shifting from park into drive.
• Input speed reads zero on a scan tool while moving.

Possible causes5

• Sensor connector unplugged or broken.
• Open sensor wiring, or lost supply voltage on sensors that need one.
• Complete sensor failure.
• Damaged internal harness if the sensor is inside the transmission.
• A fault in the transmission control module (rare).

How to diagnose5

1. Confirm the input speed reading on a scan tool stays at zero while moving.
2. Inspect the connector and wiring for disconnection or breaks, especially after recent service.
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 the shaft turns.

How to fix5

1. Reconnect the connector, or replace it if broken.
2. Repair the broken wire or supply circuit.
3. Replace the input speed sensor.
4. Replace the internal harness if the break is inside the transmission.
5. Clear the codes and confirm input speed appears and the transmission leaves limp mode.

Repair cost

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

The cost is low for reconnecting a connector or repairing a wire, and higher when an internal sensor requires removing the pan or valve body.

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