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P0584Cruise Control Vacuum Control Circuit High

The cruise control vacuum apply solenoid circuit is stuck at a higher voltage than expected, typically from an open connection or a short to battery voltage, and cruise control is disabled.

Definition

In a vacuum-operated cruise system the module drives the vacuum apply solenoid and watches the circuit's feedback voltage. P0584 sets when the circuit remains high when the solenoid is commanded on, which points to a short to battery voltage or, on low-side-driven circuits with an internal pull-up, an open in the control wire or solenoid. The result is cruise control that will not engage or drops out immediately after engaging. The engine runs normally, and on most vehicles the MIL is not illuminated for this fault.

Common causes

  • Control wire shorted to a battery-voltage circuit in a shared harness section
  • Open in the solenoid control wire or terminal with the module's pull-up holding the circuit high
  • Open vacuum solenoid winding read as a constantly high circuit
  • Corroded or loose terminal at the servo creating high resistance
  • Failed driver stage in the cruise or engine control module

Common misdiagnoses

  • Cruise servo replaced when the short to voltage is in the harness
  • Control module replaced without checking the circuit for a short to power
  • Brake or clutch pedal switch replaced for an actuator-side circuit code
  • Vacuum hoses replaced when the fault is electrical, not vacuum

Troubleshooting steps

  1. 1.Check for voltage on the control circuit

    With the solenoid commanded off, back-probe the control wire; steady battery voltage with the module disconnected indicates a short to a powered circuit.

  2. 2.Verify solenoid winding integrity

    Measure resistance across the solenoid; an OL reading means an open winding that leaves the module's pull-up voltage on the circuit.

  3. 3.Inspect terminals for high resistance

    Check terminal tension and look for corrosion at both the servo connector and the module connector, since a poor crimp behaves like an open.

  4. 4.Isolate the harness section

    Disconnect both ends and confirm the control wire has continuity end-to-end and no continuity to other wires in the same bundle.

  5. 5.Retest with an output command

    Clear the code, run the scan tool solenoid test, and confirm the circuit voltage now pulls low when commanded before returning the vehicle.

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