P0582 - Cruise Control Vacuum Solenoid Circuit Open Open Circuit

P0582 - Cruise Control Vacuum Solenoid Circuit Open (Open Circuit)

Code interpretation and system context

• What the code means: P0582 is described as an open circuit in the cruise control vacuum control circuit. In plain terms, the cruise control vacuum solenoid circuit is not receiving a proper electrical signal or cannot complete its circuit. This is an electrical/open-circuit fault rather than simply a vacuum leak.
• Where this fits in the vehicle: The issue involves the cruise control system and its vacuum-actuated components. The cruise control system relies on an electrical signal to energize a vacuum solenoid, which controls vacuum to the cruise actuator. If the circuit is open, the solenoid will not operate, and the cruise control may fail to engage, disengage, or behave erratically.
• Source notes:
  • The concept of OBD-II diagnostic trouble codes, including powertrain codes, is described in Wikipedia's OBD-II article (Diagnostic Trouble Codes; Powertrain Codes) as part of modern engines with electronic controls and code-based fault reporting.
  • The specific mapping for this issue is given in an open-source entry: (Open circuit of the cruise control vacuum control), which translates to an open circuit in the cruise control vacuum solenoid circuit.

Acknowledgments and sources

• OBD-II general definitions and powertrain code context: Wikipedia - OBD-II: Diagnostic Trouble Codes; OBD-II: Powertrain Codes.
• Specific code interpretation .
• For general diagnostic concepts and how DTCs relate to vehicle systems, the same Wikipedia OBD-II pages provide the framework for diagnosing powertrain-related faults.

Symptoms

• Cruise control will not engage or will fail to maintain/set speed when commanded.
• Cruise control may intermittently engage or disengage, or the cruise indicator may remain off, depending on the exact failure in the circuit.
• In some vehicles, the check engine light may illuminate if the PCM detects a fault condition affecting commanded actuations or related circuits, though a P0582 can occur without other engine performance symptoms if the issue is isolated to the cruise control circuit.
• Real-world complaints that align with P0582 generally describe loss of cruise control function rather than a direct engine performance problem.

Probable Causes

• Important: do not include NHTSA complaint data for P0582, so probability percentages are informed by general field experience rather than documented statistics in these sources.
• Estimated likelihood order (subject to vehicle make/model and maintenance history), with caveats:
  • Open or damaged electrical circuit to the vacuum solenoid (wiring, harness, ground, connectors): ~30-40%
  • Faulty or sticking cruise control vacuum solenoid itself (solenoid coil failure or internal opening/short): ~20-30%
  • Damaged or corroded electrical connectors/grounds to the cruise control module or solenoid: ~15-25%
  • Vacuum system issues that mimic or contribute to symptoms (vacuum line leaks, faulty check valve, or vacuum reservoir problems) and/or a vacuum source problem that affects actuation (even though the code is electrical/open circuit, vacuum issues can coexist and complicate diagnosis): ~10-20%
  • PCM or cruise-control module fault (less common, but possible if the PCM fails to drive the solenoid appropriately): ~5-15%

Safety Considerations

• When inspecting or testing the cruise control vacuum solenoid circuit, disconnect power before disconnecting any connectors if you're probing with a multimeter or applying test signals.
• Do not apply external vacuum pressure directly to the cruise control actuator while testing electrical circuits; observe solenoid operation using appropriate diagnostic methods to avoid unintended actuator movement.
• Be mindful of vehicle movement and parking brake status during road testing or when operating controls while the vehicle is stationary.

Diagnostic Approach

1) Confirm the code and related data

• Use a capable scan tool to confirm P0582 and record freeze-frame data, action taken by the PCM, and whether other DTCs are present (e.g., related to cruise control or the vacuum system).
• Note vehicle make/model/year and any recent work on the cruise control system, vacuum lines, or related wiring.

2) Visual inspection and basic integrity checks

• Inspect the entire cruise control vacuum line routing from the intake/vacuum source to the vacuum solenoid and to the cruise actuator. Look for cracks, kinks, wear, or disconnections.
• Inspect vacuum reservoir, check valve, and any serviceable vacuum components in the vacuum circuit for leaks or failure.
• Inspect electrical harnesses and connectors to the vacuum solenoid and to the cruise control module: look for damaged insulation, corroded terminals, pin deformation, loose connectors, or evidence of heat/chemical damage.

3) Electrical circuit checks (solenoid circuit)

• Locate the cruise control vacuum solenoid and identify its power and ground circuits.
• With the ignition on (engine off if required by procedure), test for voltage at the solenoid power input and verify a proper ground path. If the solenoid is active under commanded conditions, verify that the PCM is providing the proper control signal when the cruise control switch is used.
• Measure the solenoid coil resistance with an ohmmeter and compare to the vehicle's service information/specifications. A normal, expected coil resistance is typical for the specific solenoid (manufacturer or service manual data required). Note that a reading that is open (infinity) or a reading that is significantly out of spec indicates a faulty solenoid or wiring fault in the circuit.
• If the PCM is reported to command the solenoid but the solenoid does not energize, inspect the wiring harness for an open circuit or high-resistance path, and verify ground continuity from the PCM to the solenoid ground reference.

4) Functional electrical test of the solenoid

• If safe and procedure permits, perform a controlled test by energizing the solenoid while monitoring the actuator (where feasible) or by verifying PCM command through the scan tool. A functioning solenoid should energize and move the vacuum diaphragm when voltage is applied; lack of movement suggests electrical or mechanical fault in the solenoid or its drive circuit.

5) Vacuum system verification (to distinguish electrical vs. vacuum issues)

• With the engine running, check for vacuum at the solenoid output and at the actuator using a handheld vacuum gauge. If vacuum is present but the actuator does not respond to solenoid energization, the issue is likely electrical (solenoid, wiring, or PCM drive).
• If vacuum is absent or insufficient, inspect the vacuum lines for leaks, the check valve for proper operation, and the vacuum source (manifold vacuum). A vacuum leak or valve problem can prevent actuator operation even if the electrical circuit were healthy.

6) Road test and functional assessment

• After repairs, road test the vehicle to confirm cruise control engages and maintains the set speed smoothly without unintended disengagement.
• Observe for any abnormal engine behavior during cruise engagement (stumble, surges, or idle instability) which could indicate separate vacuum or control-system concerns.

6. Common repair actions based on findings

• Electrical circuit fault (open circuit, damaged harness, bad connector): repair or replace damaged wiring, clean/repair grounds, or replace the affected connector; recheck circuit continuity and resistance.
• Faulty solenoid: replace the cruise control vacuum solenoid; ensure correct part number for the vehicle and verify coil resistance/specs after installation.
• Vacuum system issue: replace cracked vacuum hoses, faulty check valve, or defective vacuum reservoir; ensure proper routing and secure connections.
• Loose or corroded grounds to the cruise control system: repair grounding path and ensure solid electrical contact.

This diagnostic guide was generated using verified reference data:

• Wikipedia Technical Articles: OBD-II
• Open-Source OBD2 Data: N/A (MIT)

Content synthesized from these sources to provide accurate, real-world diagnostic guidance.

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