Cruise Control Vent Control Circuit Low
The P0587 code indicates that the Powertrain Control Module (PCM) has detected a low voltage condition in the cruise control vent control circuit. This circuit controls the vent solenoid that releases vacuum from the cruise control servo to disengage cruise control. A low voltage reading suggests a short to ground, open circuit, or faulty component in the vent solenoid circuit.
1. Most Common Causes
- Short to ground in the cruise control vent circuit wiring
- Open circuit in the power or signal wire to the vent valve
- Corroded, bent, or poor contact in the electrical connector at the actuator or PCM
- Faulty cruise control vent valve (actuator) with internal short or open
- Damaged powertrain control module (PCM) - rare
2. Symptoms You Will Notice
- Cruise control inoperative
- Cruise control light on dash illuminated
- Check Engine Light on
- Cruise control may not disengage properly
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all codes and freeze frame data.
Step 2: Inspect the cruise control vent solenoid and its wiring for damage, corrosion, or loose connections.
Step 3: Test the vent solenoid resistance with a multimeter (typically 20-40 ohms).
Step 4: Check for voltage at the solenoid connector with the ignition on (should be near battery voltage).
Step 5: If voltage is low, check for shorts to ground or open circuits in the wiring harness.
Step 6: Replace the vent solenoid if it fails resistance or voltage tests.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe to drive, but cruise control will be disabled. If the vent solenoid fails in a way that prevents cruise disengagement, it could be a safety concern. Have it repaired promptly.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for parts and labor, depending on the vehicle and shop rates. The vent solenoid itself is often inexpensive.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.