P0566

Severity: High

Cruise Control Off Signal Malfunction

Last updated: July 2026

System

Powertrain

Subsystem

Vehicle Speed, Idle & Auxiliary Inputs

Code Type

Generic (SAE)

What does P0566 mean?

P0566 is a generic (SAE) powertrain diagnostic trouble code. It is defined as "Cruise Control Off Signal Malfunction". It falls under the vehicle speed, idle & auxiliary inputs area of the vehicle’s powertrain system, and has the same core meaning across most makes and models.

When is P0566 set?

The onboard diagnostic system sets P0566 when it detects a condition matching "cruise control off signal malfunction" in the vehicle speed, idle & auxiliary inputs circuit or system. When the fault is confirmed, the module stores the code and, in most cases, turns on a warning light.

This code is generally considered serious. Continued driving may worsen the fault or affect safety and drivability. Have it diagnosed promptly.

Common symptoms

Check engine light (MIL) illuminated
Rough running, hesitation or loss of power
Increased fuel consumption
Difficulty starting or stalling

Possible causes

A failing or contaminated sensor in the affected circuit
Wiring, connector or ground problems
Vacuum, intake or exhaust leaks
A worn or failing mechanical component
Occasionally, a fault in the control module itself

What to check first

Scan for all stored and pending codes and note the freeze-frame data
Inspect the wiring and connectors for the affected circuit
Check for related leaks, loose components or obvious damage
Test the relevant sensor and its reference/ground with a meter
Clear the code and retest to see whether it returns

Frequently asked questions

What does the P0566 code mean?

P0566 means "Cruise Control Off Signal Malfunction". It is a generic powertrain trouble code in the vehicle speed, idle & auxiliary inputs area.

Is it safe to drive with a P0566 code?

Because this code is often serious, it is best to limit driving and have the vehicle diagnosed as soon as possible. Continuing to drive may worsen the fault or affect safety.

How do I fix a P0566 code?

There is no single fix. Start by confirming the code with a scan tool, then work through the likely causes and checks above — inspecting wiring, connectors and the relevant components before replacing any parts. On most vehicles, confirm the diagnosis before repairs.

Can I clear the P0566 code myself?

You can clear the code with an OBD-II scan tool, but if the underlying fault is still present it will usually return. Clearing without repair is only useful to confirm whether the fault is active.

Related codes

P0567

Cruise Control Resume Signal Malfunction

P0568

Cruise Control Set Signal Malfunction

P0565

Cruise Control On Signal Malfunction

P0569

Cruise Control Coast Signal Malfunction

Important

This information is provided for general reference only. It is not repair advice and may not apply to every make or model. Manufacturer-specific codes can differ. Always confirm a diagnosis with a scan tool and, where needed, a qualified technician before replacing parts.