Open circuit or poor connection in the wiring to the cruise control vacuum solenoid or valve; Faulty vacuum control solenoid or vent valve with an open winding; Corroded, loose or damaged connector terminals at the solenoid or control unit; Blown fuse or loss of power or earth supply to the cruise control circuit; Faulty brake or clutch switch circuit sharing the supply, depending on model; Fault inside the engine control unit or cruise control module driver.

P0582

Cruise Control Vacuum Control Circuit/Open.

Generic
Powertrain
Generic code
Low severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
5: AreaVehicle speed, idle control and auxiliary inputs
82: FaultThe specific fault in that area

What it means

P0582 means the engine control unit has detected an open circuit in the control circuit for the vacuum-operated cruise control actuator (the vacuum solenoid or vent/vacuum valve). The control unit monitors the circuit when it commands the solenoid and sets the code when the electrical signal does not match what it expects, such as no current flow. It is mainly found on older vehicles that use a vacuum servo to move the throttle linkage, and the details vary by model.

Symptoms

Cruise control will not engage or will not hold set speed
Cruise control cuts out unexpectedly or surges
Cruise control warning light or malfunction message may show
Engine warning light on
Cruise control buttons appear dead or unresponsive

Possible causes

Open circuit or poor connection in the wiring to the cruise control vacuum solenoid or valvelikely
Faulty vacuum control solenoid or vent valve with an open windinglikely
Corroded, loose or damaged connector terminals at the solenoid or control unitpossible
Blown fuse or loss of power or earth supply to the cruise control circuitpossible
Faulty brake or clutch switch circuit sharing the supply, depending on modelrare
Fault inside the engine control unit or cruise control module driverrare

How to diagnose

Read the stored codes and freeze frame data, note any other cruise, brake switch or throttle codes, then check for any relevant technical service bulletins for the model
Check the fuse for the cruise control circuit and the condition of the relevant relay if fitted
Visually inspect the wiring and connector at the vacuum solenoid or actuator for chafing, heat damage, corrosion or water ingress
Check the vacuum hoses and servo for splits or perforations, as these can accompany an electrical fault
Using the wiring diagram for the vehicle, measure the solenoid winding resistance and compare it with the specification
Check for supply voltage and earth at the solenoid connector with the ignition on and cruise requested
Wiggle-test the harness while monitoring the circuit to find intermittent open circuits
If wiring and solenoid are good, check the control unit output and connector pins before considering the unit itself

How to fix

Repair or replace damaged wiring and restore the open circuit
Clean or replace corroded or loose connector terminals and refit the connector securely
Replace the faulty vacuum solenoid or valve assembly
Replace the blown fuse after finding and fixing the cause of the failure
Replace any split vacuum hoses or a leaking servo found during testing
Repair or replace the control unit only after all other causes are ruled out, and confirm any software update requirement for the model

Can I keep driving?

Low severity

The car is safe to drive as normal, but cruise control will probably be unavailable. Book it in for repair at a convenient time.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.