Cruise Control Vent Control Circuit Low
Your cruise control's vent solenoid isn't getting enough electrical power to open properly, like a valve stuck partially closed. This prevents the cruise control system from releasing throttle pressure when it should slow down.
The ECM monitors voltage and current supplied to the cruise control vent solenoid during operation. When the solenoid is commanded to open, the ECU expects to detect sufficient voltage drop across the circuit. A low voltage reading indicates poor electrical connection, damaged wiring, or solenoid failure.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Vent Solenoid Voltage | 11-14V when solenoid activated | Below 10V or no voltage detected |
| Solenoid Current Draw | 0.5-1.5 amps when activated | Below 0.3 amps or open circuit |
Code P0587 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P0587 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.