We admit it. There might be one person who understands your GM vehicle better than Goodwrench. Your vehicle itself. With the help of OnStar, you can listen to your GM vehicle and find out exactly what maintenance it needs. Knowing your vehicle's precise needs can improve fuel economy, reduce emissions and oil waste and possibly save you money and worry.

When you subscribe to OnStar Vehicle Diagnostics*, your GM vehicle will undergo hundreds of checks on its key operating systems (including engine, air bags, anti-lock brakes and more) about every 30 days – while you drive.

Then, you receive an automatic email report on the results. Each report also includes your current mileage, remaining oil life and more.

Between monthly reports, you can also request Goodwrench On Demand Diagnostics checks – just push your blue OnStar button.

Plus, Goodwrench is now teaming up with OnStar Vehicle Diagnostics to give eligible subscribers the chance to receive automatic Goodwrench service updates, specific to your GM car or truck.

 Visit OnStar.com for more diagnostic details

*Requires valid email address. Diagnostic capabilities vary by model.