Technical Description of OBD-II Trouble Code
The circuit for controlling the cruise control vacuum is open.
What does that mean?
This is a generic diagnostic trouble code (DTC) for powertrain issues and is commonly found in OBD-II vehicles. This code can apply to various vehicle makes such as Dodge, Chrysler, Jeep, Chevy, Hyundai, Ram, Ford, etc.
Manufacturers often use a vacuum-controlled system to operate the cruise control. The vacuum control circuit is an important part of this system. The engine control module (ECM) monitors and adjusts the vacuum control side based on the driver’s cruise control demands. If the ECM loses its ability to monitor the cruise control vacuum control circuit, the cruise control may stop functioning properly. In some systems, a vacuum solenoid controls the vacuum flow to the control side of the system, while in others, the cruise control servo handles the vacuum responsibilities. This fault could be caused by an electrical issue, a mechanical issue, or a combination of both.
The ECM has detected a fault in the cruise control vacuum control circuit while monitoring various sensors, circuits, switches, and systems in the vehicle. This fault is likely due to one or more electrical values going beyond the desired range specified by the manufacturer.
What is the severity of this DTC?
In terms of safety, this fault is not a major concern. However, it is recommended to address any issues within the vacuum system, which is often supplied or recycled by the engine, as neglecting to fix a vacuum system can have consequences. The severity of this DTC is considered low-medium.
If you have determined that the engine is not affected by this fault, especially in non intake-supplied vacuum systems, and you can live without cruise control, you can delay fixing this issue if you have budget constraints or other higher priority matters.
What are some of the symptoms of the code?
Symptoms of a P0582 diagnostic code may include:
What are some of the common causes of the code?
Possible causes for this P0582 cruise control code may include:
What are some P0582 diagnostic and troubleshooting steps?
The first step in troubleshooting any malfunction is to refer to the Technical Service Bulletins (TSB) for known issues with the specific vehicle.
Advanced diagnostic steps will vary depending on the vehicle and may require specialized equipment and knowledge. The following basic steps can be taken, but it is recommended to consult a vehicle-specific repair guide for precise steps:
Basic Step #1
Inspect the cruise control system under the hood. Trace the vacuum control line to determine its path and what it controls. If it connects directly to a vacuum solenoid, thoroughly check the vacuum lines, solenoids, and cruise control servo for any physical damage. Repair or replace any obvious issues before further diagnosis.
Note: When inspecting the cruise control servo, ensure that the cable is not seized, as this can affect the monitored electrical values.
Basic Step #2
If a cruise control vacuum solenoid is present, verify its electrical values to rule out any internal faults. Refer to the vehicle’s service manual for specific values and procedures. Depending on the vehicle, the solenoid may be mounted on the firewall, fender wells, intake manifolds, etc. If the recorded values are outside the manufacturer’s desired range, replace the solenoid, clear the engine light, and test drive the system.
Basic Step #3
If you have access to a vacuum gauge, monitor the vacuum within the system. It is crucial to measure the vacuum from specific ports on the intake systems, typically located on the intake manifold. The vacuum reading should be around 50-55 kPa at operating temperature, with correct ignition timing. However, this may vary depending on the engine.
