1 Aug 2013

Quick Guide to Dashboard Warning Lights

Over the years, developments in vehicle technology have significantly improved the capabilities of the dashboard to warn on car faults. Utilising a vast range of sensors and sophisticated on-board equipment, your vehicle is able to self-diagnose a wide range of issues relating to its health and performance.

This infographic guide to dashboard warning lights was created by Claytons MOT & Service Centre in Leeds to provide a quick reference to the most commonly used lights. Highlighting what each of the lights often indicates and the best course of action for remedying the issue, the graphic helps to improve awareness for what is a very important aspect of maintaining a safe and reliable car. Addressing and fixing a fault at an early stage can often reduce the possible impact it can have on your car, thus saving money on future repair bills that may arise if the issue is left to escalate into a bigger problem.

Please note: each car model has its own individual set of specific dashboard warning lights and precise information relating to each one can be found in the driver handbook. Please seek professional advice from your manufacturer or a qualified vehicle technician to with any issue you’re unsure about.

Overview of Commonly Used Dashboard Warning Lights


Infographic by the team at Claytons MOT & Service Centre


In Focus: Common Warning Light Issues

Battery Warning Light


This battery charge warning light should illuminate when the ignition is switched on and then extinguish as soon as the engine starts. If it does not illuminate at all, or if it illuminates while driving, your battery is not being charged as there is a fault with your charging system.

Illumination of the battery warning light may be due to one of the following;

• Problems with the car battery or starter terminal
• Alternator drive belt becoming broken or loose
• None functioning alternator

Whatever the possible cause of fault, immediately move the vehicle to a safe location and switch off the engine, seeking qualified assistance.


Brake System Alert


This light will remain illuminated when the handbrake is engaged. Illumination after releasing the handbrake may indicate low brake fluid level.

Refer to the handbook and add the correct brake fluid at once to bring the level up to the max mark. As the brakes wear, the fluid level will slowly drop, so check your brake fluid level frequently to ensure there is no further rapid loss of fluid.

If the brake fluid is too low and brake pedal travel is distinctly longer than usual, one of the two hydraulic brake circuits may have failed. Do not continue your journey and seek assistance.

If the light remains illuminated, even though the brake fluid level is correct, this may indicate a sensor fault. Take your vehicle to a dealer or garage as soon as possible.


ABS Warning Light


When the ignition is switched on, the light illuminates briefly to confirm that the system is operational. If it illuminates when driving, it indicates a malfunction. Have this checked as soon as possible.

Normal braking (without ABS) will be generally be maintained and many cars will be safe to drive on, but some will not - check the handbook for advice on what the manufacturer recommends.


Engine Management Light


It is impossible to determine the nature of the problem without diagnosing the fault codes. Once this has been done, further diagnosis and testing may be required to isolate the fault so the correct parts(s) can be replaced.

Don't be alarmed by the engine management light. Often the problem is something minor that won’t affect the way your engine runs, or you car's ability to start or drive. Depending on the nature of the fault, your engine may not run as good as it normally does, or it may use more fuel than usual.

Common reasons for the engine management light to illuminate include;

• A loose fuel cap
• Issue with the spark plugs
• Dirty fuel injectors
• Failure of an engine sensor such as the oxygen sensor, throttle position sensor or manifold absolute pressure sensor
• A problem in an emissions control system or device such as the EGR valve or catalytic converter.

Please view this guide for more information on car warning lights. http://www.claytonsmot.co.uk/warning-light-diagnostics.php