P0587 – Cruise Control Vent Control Circuit Low

P0587 is an OBD-II trouble code related to your vehicle’s cruise control system, specifically the “cruise control vent control circuit low.” In plain language, your car’s computer is seeing an electrical signal that’s lower than it should be in the part of the system that vents or releases vacuum/pressure for cruise control. You’ll usually notice that cruise control won’t set or will cancel unexpectedly, but the engine itself may still run fine. While this code isn’t usually dangerous, it’s worth diagnosing so you don’t ignore a growing electrical or wiring issue.

What Does P0587 Mean?

P0587 is defined as “Cruise Control Vent Control Circuit Low.” Your ECU (engine control unit) monitors the electrical circuits that control the cruise control actuator. On many vehicles, this involves a vacuum or electronic actuator with vent and apply solenoids. When the ECU sees a voltage lower than the expected range on the vent control circuit, it flags P0587.

This usually points to a problem with the wiring, the cruise control switch/actuator, or a faulty vent solenoid. It does not mean your engine is about to fail, but it does mean your cruise control system is not working as designed.

Quick Reference

• Code: P0587
• Definition: Cruise Control Vent Control Circuit Low
• Main system: Cruise control / speed control
• Typical severity: Low to moderate (comfort/convenience issue)
• Most common cause: Faulty vent solenoid or wiring issue

Real-World Example / Field Notes

In the shop, I usually see P0587 on vehicles where the owner reports, “Cruise just stopped working one day.” No major drivability problems, no strange noises—just a dead cruise control light or a system that won’t set. On some models, especially older Hyundai, Kia, Subaru, and GM vehicles, corrosion at a connector near the brake booster or under the dash is the culprit. A quick voltage check at the vent solenoid often reveals low or no voltage, and cleaning or repairing a single connector brings the cruise control back to life.

Symptoms of P0587

• Cruise control inoperative – Cruise will not set or resume at any speed.
• Cruise disengages – System may set briefly, then cancel on its own.
• Warning light – Cruise control indicator may flash or fail to illuminate.
• Check engine light – MIL/SES light may come on and store P0587 in memory.
• Intermittent operation – Cruise works some days and not others, especially after rain or humidity.
• Other cruise codes – Additional DTCs related to cruise control circuits may appear.
• No change in engine performance – Acceleration, idle, and fuel economy usually remain normal.

Common Causes of P0587

Most Common Causes

• Faulty cruise control vent solenoid/actuator – Internal failure or short to ground causing low circuit voltage.
• Damaged wiring harness – Chafed, pinched, or corroded wires between ECU and cruise actuator or under-dash harness.
• Corroded or loose connectors – Moisture intrusion at connectors near the brake booster, fender well, or under the steering column.
• Faulty cruise control switch module – Steering wheel or stalk switch sending incorrect signals to the ECU.
• Blown fuse or poor power/ground – Shared fuse or ground point for the cruise system causing low voltage on the vent circuit.

Less Common Causes

• Brake pedal switch issues – A misadjusted or failing brake switch can confuse the cruise system and affect vent control logic.
• Clock spring (steering wheel spiral cable) failure – On vehicles with wheel-mounted cruise buttons, a bad clock spring can disrupt signals.
• ECU/PCM internal fault – Rare, but possible if all wiring and components test good and voltage drivers are weak.
• Aftermarket accessories – Poorly installed remote starters, alarms, or audio systems spliced into cruise or brake circuits.
• Water damage – Flooding or leaks into the cabin or engine bay affecting connectors and modules.

Diagnosis: Step-by-Step Guide

To diagnose P0587 properly, you’ll want a basic scan tool (ideally one that can read live data and Mode $06), a digital multimeter, a wiring diagram for your vehicle, and simple hand tools. If you’re comfortable with electrical testing, you can do much of this yourself; otherwise, this is a straightforward job for a qualified technician.

1. Confirm the code and check for companions. Plug in a scan tool, confirm P0587, and look for related cruise or brake switch codes (P0585–P0590 range). Note freeze frame data to see when the fault occurred.
2. Check cruise control operation. With the engine running, attempt to turn on and set cruise at a safe speed (road test if possible). Note whether the cruise light comes on, flashes, or stays off completely.
3. Inspect fuses and power supply. Locate the fuse(s) for cruise control, stop lamps, and related circuits. Test fuses with a test light or meter, not just visually. Verify good power and ground at the cruise actuator connector.
4. Perform a visual inspection of wiring. Follow the harness from the cruise actuator/vent solenoid toward the ECU and under the dash. Look for rubbed-through insulation, broken clips, green corrosion, or signs of water intrusion.
5. Test the vent control circuit voltage. With the key on, back-probe the vent control wire at the actuator. Compare voltage to spec from the service manual. A “low” reading (near 0 V when it should be higher) points to a short to ground or internal actuator fault.
6. Check actuator/solenoid resistance. Key off, unplug the actuator, and measure resistance across the vent solenoid terminals. Compare to factory specs. Infinite resistance or very low resistance indicates a bad solenoid.
7. Verify continuity to the ECU. If the actuator tests good, check continuity and resistance from the vent control pin at the actuator connector to the corresponding pin at the ECU. High resistance or an open circuit means damaged wiring.
8. Inspect brake switch and related inputs. Use the scan tool to monitor brake switch status and cruise control switch inputs while pressing the brake and operating the cruise buttons. Incorrect or stuck signals can affect vent operation.
9. Check Mode $06 data (if available). Some scan tools let you see cruise control monitor test results. This can help confirm whether the ECU is repeatedly failing the vent circuit test or if the fault is intermittent.
10. Perform a wiggle test. With the engine running and scan tool connected, gently move the harness and connectors for the cruise system. If the code sets or the cruise light flickers, you’ve likely found a wiring or connector issue.

Pro tip: On many vehicles, the cruise actuator and vent solenoid share grounds and power feeds with other systems. If you see multiple unrelated electrical quirks (airbag light, horn issues, intermittent radio), focus on shared grounds and connectors before condemning the actuator or ECU.

Possible Fixes & Repair Costs

Once you’ve pinpointed the cause of P0587, repairs are usually straightforward. Common fixes include repairing or replacing damaged wiring, cleaning or replacing corroded connectors, replacing the cruise control actuator/vent solenoid, or replacing a faulty steering wheel/stalk cruise switch or brake switch. In rare cases, an ECU may need repair or replacement.

Typical repair costs vary by vehicle and shop rate. A simple wiring repair or connector clean-up can run $75–$200. Replacing a cruise actuator or vent solenoid usually falls in the $200–$450 range parts and labor. A new steering wheel switch or clock spring can cost $250–$600. ECU-related repairs, while rare for this code, can exceed $700. Factors like vehicle make, parts availability, and diagnostic time all affect the final bill.

Can I Still Drive With P0587?

Yes, in most cases you can continue driving with P0587 without immediate risk to the engine or transmission. The main issue is loss of cruise control functionality, which is more of a convenience problem than a safety-critical failure. However, if the code is caused by wiring damage, corrosion, or a shared power/ground problem, ignoring it could allow a small electrical issue to grow into a bigger one that affects other systems. It’s best to schedule diagnosis and repair when you can, especially if other warning lights are present.

What Happens If You Ignore P0587?

If you ignore P0587, you’ll likely just live without cruise control, but the underlying electrical problem can worsen over time. Corrosion can spread, wiring can overheat or break, and shared circuits might start causing issues with brake lights, steering wheel controls, or other modules. In the long run, fixing a simple vent control circuit fault now is cheaper and easier than chasing multiple intermittent electrical problems later.

Last updated: March 1, 2026

Vehicles Commonly Affected by P0587

P0587 can appear on many OBD-II vehicles, but it’s more frequently seen on certain makes that use vacuum or electronic cruise actuators with dedicated vent control circuits. In the field, this code is fairly common on:

• Hyundai and Kia sedans and SUVs (Elantra, Sonata, Santa Fe, Optima, Sportage)
• Subaru models (Impreza, Forester, Outback) with older-style cruise control systems
• GM vehicles (Chevrolet, GMC, Buick) from the mid-2000s to early 2010s
• Ford and Mazda platforms that share cruise control hardware
• Some Toyota and Honda models, though less frequently than the brands above

Even if your vehicle isn’t on this list, the diagnostic approach and repair options for P0587 are very similar across most modern cars and light trucks.