P0809 Clutch Position Sensor Circuit Intermittent

P0809 indicates an intermittent clutch position sensor circuit fault. The clutch-position signal drops out or becomes invalid only at certain times.

Code details

Generic OBD-II · P0

System: Transmission
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not replace the clutch sensor without first reproducing the intermittent signal loss.

Symptoms of P0809

Harsh, delayed, or slipping shifts, or being stuck in one gear.
Check-engine light, sometimes with limp-home mode.
Flaring RPM or a shudder under load.

Common causes of P0809

Low or degraded transmission fluid.
A failing speed sensor, shift solenoid, or pressure-control circuit.
Wiring, connector, or internal hydraulic/mechanical faults.

Useful checks before replacing parts

Graph clutch position data while slowly pressing and releasing the pedal, then repeat with vibration and heat if needed.
Inspect clutch pedal sensor adjustment, connector fit, terminal tension, wiring movement at the pedal, and shared reference or ground circuits.
Check for start, cruise cancel, rev-match, shift inhibit, or manual transmission control symptoms during the dropout.

Related OBD-II codes

These nearby transmission entries can help compare wording and pin down the fault area.