What Should I Do If My Mercedes-Benz Check Engine Light Is On? 

How to Respond to a Mercedes-Benz Check Engine Light 

When the check engine light illuminates on your Mercedes-Benz dashboard, here’s what you should do: 

1. Check your owner's manual 

Your owner’s manual will offer insight into the possible reasons your check engine light is on. Some common triggers include a loose gas cap, a faulty oxygen sensor, or more serious engine-related concerns. 

2. Check the gas cap 

Sometimes, the issue is as simple as a loose or damaged gas cap. Tighten the gas cap securely and drive for a bit to see if the light turns off. 

3. Watch for performance issues 

If you notice your vehicle driving differently—such as stalling, reduced power, or unusual noises—it may be a sign of a more serious issue. In that case, avoid driving the car and schedule service as soon as possible. 

4. Don’t ignore it—schedule a diagnostic check 

Even if there are no noticeable symptoms, it’s important to have your vehicle diagnosed by a professional. The check engine light is part of your Mercedes-Benz car’s onboard diagnostics system and should never be ignored for too long. 

Frequently Asked Questions about the Mercedes-Benz Check Engine Light 

Q: Can I keep driving with the check engine light on? 

A: If the light is solid and your car seems to be driving normally, it may not be urgent, but you should still schedule service soon. If the light is flashing, it indicates a severe engine misfire—stop driving and seek service immediately. 

Q: What are the most common reasons the check engine light comes on? 

A: Common causes include a loose gas cap, oxygen sensor failure, catalytic converter issues, mass airflow sensor problems, and spark plug or ignition coil failures. 

Q: Will the check engine light reset itself? 

A: In some cases, yes—especially if the issue was minor and resolved (like a tightened gas cap). However, most of the time, the issue needs to be diagnosed and repaired, and the light should be reset by a technician. 

Q: Can I diagnose the issue myself? 

A: While DIY scan tools are available, they may not give you the full picture. Our technicians use Mercedes-Benz-specific diagnostic tools to pinpoint the exact cause and offer the correct repair.