how to fix a high idle issue in my Volkswagen Golf MK7.5 (2020-Present)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Park the vehicle on a level surface and engage the parking brake.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Clean Throttle Body

1. Remove Throttle Body:
   • Disconnect the electrical connector from the throttle body.
   • Remove the intake duct connected to the throttle body (usually secured with hose clamps).
   • Unbolt the throttle body from the intake manifold using the appropriate socket (usually T30 or T25).
2. Clean Throttle Body:
   • Use throttle body cleaner and a clean cloth or soft brush to remove carbon buildup from the throttle plate and housing.
   • Ensure the throttle plate can move freely without obstruction.
3. Reinstall Throttle Body:
   • Reattach the throttle body to the intake manifold, torque bolts to manufacturer specifications (typically around 10 Nm).
   • Reconnect the intake duct and electrical connector.

3. Check for Vacuum Leaks

1. Visual Inspection:
   • Inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
   • Replace any damaged hoses as necessary.
2. Smoke Test (if available):
   • Use a smoke machine to introduce smoke into the intake system, watching for smoke escaping from leaks.

4. Test and Replace Sensors (if necessary)

1. Mass Air Flow Sensor:
   • Disconnect the MAF sensor and inspect for dirt. Clean with MAF cleaner or replace if faulty.
2. Coolant Temperature Sensor:
   • Check the resistance using a multimeter; replace if it does not meet specifications.

5. Reconnect Battery

• Reconnect the negative battery terminal securely.