OBD-II code P0564 indicates a malfunction in the cruise control multi-function input circuit. The engine control module (ECM) or body control module (BCM) has detected an abnormal voltage or signal from the cruise control switch assembly, which typically integrates multiple functions (set, resume, cancel, on/off) into a single circuit using varying resistances. This code sets when the module cannot interpret the switch's input correctly, often due to a faulty switch, wiring issue, or clock spring failure.
The most common cause is a worn or damaged switch assembly, leading to incorrect resistance values or intermittent contact. This is often due to age, contamination, or physical wear.
Open circuits, short to ground, or high resistance in the wiring harness or connectors between the switch and the control module can cause signal errors. Common locations include the steering column, clock spring connector, or under-dash harness.
The clock spring provides electrical connections to the steering wheel. A broken or worn clock spring can interrupt the cruise control switch signal, often accompanied by other steering wheel control failures or an airbag warning light.
A blown fuse in the cruise control circuit or a loss of power/ground to the switch can prevent the system from operating, though this may also set other codes.
A module failure is rare and should only be considered after all other causes have been thoroughly ruled out. Internal circuit damage or software glitches can misinterpret switch signals.
It means the vehicle's computer has detected a problem with the electrical circuit for the cruise control multi-function switch, which typically handles several cruise commands through a single input.
Yes, the vehicle is safe to drive. The code only affects the cruise control system and does not impact engine performance or safety systems, but cruise control may be unavailable.
No, a faulty engine or body control module is rarely the cause. The problem is almost always the cruise control switch, clock spring, or wiring. Replacing the module without proper diagnosis is a common misstep.
It depends on the vehicle. On many models, the switch is accessible and can be replaced with basic tools, but some require steering wheel removal and careful handling of the airbag system. Always consult a service manual and disconnect the battery before working on airbag components.