The P0573 code on your 2023 Volvo XC90 indicates a high voltage condition in the cruise control brake switch circuit, often meaning the switch appears stuck in the 'off' (brake not pressed) position even when braking.
Stuck-Off Switch Danger
This condition is potentially dangerous—the cruise control system may not disengage when you press the brake pedal because it doesn't see the brake signal. While other brake switch circuits usually provide backup, this needs immediate attention.
XC90 Pilot Assist
The 2023 XC90 features Volvo's Pilot Assist semi-autonomous driving system. Brake switch input is critical for safety—the system must immediately recognize driver braking. A fault in this circuit affects system reliability.
Causes of Stuck-Off Reading
The brake switch may be misadjusted, not making contact when the pedal is pressed. An open circuit (broken wire) prevents signal transmission. The switch may have failed open internally. Disconnected connector creates open circuit. Corroded terminals prevent contact closure.
Diagnostic Process
Use Volvo VIDA to monitor brake switch signal while pressing the pedal. The signal should change when braking. If it stays high regardless of pedal position, the circuit is open or switch isn't activating. Test switch operation directly. Check wiring continuity from switch to module.