Updated April 2026 · AI-Diagnostics-Pro · 6 min read
Solid amber: A stored fault. Something needs attention but isn't causing immediate damage. Drive cautiously to a garage within a few days.
Flashing amber: Active misfire. Reduce speed immediately and get to a garage urgently.
Red warning light: Stop immediately. Pull over and don't drive further.
Worn spark plugs, failed ignition coil, dirty injector, vacuum leak or low compression. Most flashing light faults are caused by worn spark plugs (£20–£50 for a full set) or a failed ignition coil (£20–£60 each).
Yes — two ways. Any illuminated engine management light is automatic MOT failure. Active misfires also produce high emissions that fail the emissions test independently.