About the VHI

Published since 2011, the CarMD® Vehicle Health Index™ reports on the most common check engine light- related problems, repairs and associated costs, regional insights, and make and model reliability rankings.

CarMD is uniquely qualified to provide unbiased data on repair costs and trends having built the most dynamic database of failures and repairs related to vehicle on-board diagnostics. The data comes from each vehicle’s OBDII system, reported by millions of vehicle owners and the professionals who service them.

CarMD is updating its Vehicle Health Index reports to include new datasets as vehicles become more complex with more dashboard warning lights, systems and sensors. Stay tuned for new Vehicle Health Index reports coming soon!

Check Engine Light Insight

The check engine light comes on when a vehicle’s computer detects a problem that affects emissions or drivetrain issues. Don’t panic when the check engine light comes on, but get it diagnosed ASAP. It can be as simple as a loose gas cap. But a flashing check engine light can indicate a more serious problem such as an engine misfire that needs immediate attention from roadside assistance. If your car’s check engine light is on, it will not pass its state emissions test and negatively impact fuel economy if ignored.