P0588 Cruise Control Vent Control Circuit High

P0588 indicates a high condition in the cruise control vent control circuit. The controller sees vent solenoid voltage or feedback above the expected range.

Code details

Generic OBD-II · P0

System: Speed / Idle
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not condemn the control module until the vent circuit wiring and ground path are checked.

Symptoms of P0588

Unstable, high, or low idle, or stalling.
Erratic speedometer, cruise-control, or shift behaviour.
Check-engine light with a hesitation or surge.

Common causes of P0588

A dirty throttle body, idle-control valve, or throttle-position sensor.
A failing vehicle-speed or wheel-speed sensor, or its wiring.
Vacuum leaks or a related sensor forcing the idle/speed strategy.

Useful checks before replacing parts

Review vent solenoid command, circuit voltage, current draw, driver status, cruise enable conditions, and freeze-frame data.
Inspect for short-to-voltage faults, open grounds, connector corrosion, stuck solenoid loads, and harness damage near heat or moving parts.
Command the vent circuit and confirm voltage, current, and vacuum release behavior match the request.

Related OBD-II codes

These nearby speed / idle entries can help compare wording and pin down the fault area.