Engine Warning Light On? What You Need to Know

20 March 2026 · 5 min read

Solid vs Flashing — The Difference

A solid yellow engine warning light means something has been spotted that needs attention. It is not an emergency, but you should get it checked soon — within a week or two.

A flashing red or orange warning light is more serious. It usually means the engine is misfiring or a major fault has been detected. Pull over safely and call for help. Do not keep driving — you can damage the engine.

What Causes the Light to Come On

The engine warning light (also called the MIL or "Check Engine" light) comes on when the engine control unit detects a fault. Common causes include: a loose or faulty fuel cap, an O2 sensor fault, a catalytic converter issue, a faulty spark plug, or an EGR valve problem.

None of these are something you should ignore. A small fault can turn into an expensive repair if left unchecked.

What We Do to Diagnose It

We have professional diagnostic equipment that connects to your engine control unit and reads the fault code. The code tells us exactly what system is affected.

We then carry out additional tests — electrical checks, pressure tests, or sensor checks — to confirm the real problem. This stops us guessing or swapping parts that do not need replacing.

Getting It Fixed in Bilston

Do not drive around with a warning light on. Call Wolverhampton Auto Care on 01902 494948 in Bilston to book a diagnostic appointment. We will read the fault code, explain what it means, and give you a clear quote for the fix.

If it is flashing, call us straight away. We can often fit you in the same day. Serving Bilston, Darlaston, Willenhall, Walsall and the surrounding area.

Book a diagnostic check →

Need help with your car?

Call Wolverhampton Auto Care for clear advice and a fast booking.

Call 01902 494948