P0580 Cruise Control Multi-Function Input A Circuit Low

P0580 points to a low condition in Cruise Control Multi-Function Input A circuit. The controller sees input A below the expected voltage or data range.

Code details

Generic OBD-II · P0

System: Speed / Idle
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 cruise switches blindly before testing the shared input A circuit and clockspring.

Symptoms of P0580

Unstable, high, or low idle, or stalling.
Erratic speedometer, cruise-control, or shift behaviour.
Check-engine light with a hesitation or surge.

Common causes of P0580

A dirty throttle body, idle-control valve, or throttle-position sensor.
A failing vehicle-speed or wheel-speed sensor, or its wiring.
Vacuum leaks or a related sensor forcing the idle/speed strategy.

Useful checks before replacing parts

Check input A voltage, switch-state data, reference voltage, ground, brake switch status, vehicle speed, and freeze-frame conditions.
Inspect for short-to-ground faults, open reference circuits, damaged clockspring wiring, stuck switch contacts, and connector corrosion.
Measure the input with each switch position to identify whether one command or the shared circuit is pulling the value low.

Related OBD-II codes

These nearby speed / idle entries can help compare wording and pin down the fault area.