P0805: Clutch Position Sensor Circuit

What it means

General electrical fault on the clutch position sensor A circuit — used in dual-clutch and automated-manual transmissions to monitor clutch fork or release-bearing position. Without a valid signal the TCM cannot close the loop on clutch engagement.

At a glance

• Usually lights the check-engine light

How it works

Clutch position sensor A reports clutch position to the control module in a dual-clutch or automated-manual transmission. The module uses the signal to manage clutch engagement and sets P0805 when it detects a general electrical fault in sensor A’s circuit.

Common causes

Most likely first.

1. Open or shorted wiring
2. Failed Hall element

Symptoms

• Check engine or transmission warning light on
• Harsh, delayed, or missing shifts
• Possible limp mode (locked in one gear)
• Slipping or shuddering during gear changes

How to diagnose it

1. Scan the transmission module for related codes and save freeze-frame data, including clutch position and commanded position if available.
2. Compare sensor A’s reported position with clutch movement during a safe, supported diagnostic check.
3. Inspect sensor A’s connector and wiring for looseness, corrosion, chafing, or an open circuit.
4. Test sensor A’s supply, ground, and signal circuit against the wiring diagram and manufacturer’s specification.
5. If the circuit is sound, test the sensor and then check the module connector and input circuit.

Common fixes

• Secure or clean the clutch position sensor A connector.
• Repair an open or shorted wire in sensor A’s circuit.
• Replace a confirmed failed clutch position sensor A.
• Repair a confirmed control-module input fault.

Can I keep driving?

Avoid driving if the transmission shifts unpredictably, slips, or cannot select gears, since clutch engagement may be unreliable. If symptoms are mild, drive only as needed to reach a safe place for diagnosis.