Wednesday, 21 February 2018

Types of Fault Light in Cars

A fault light is an optical signal. It informs you that a device has been activated in the car, whether it is working correctly or faulty, or whether it has failed completely. The corresponding symbol must stand out clearly when lighting up, but not always be visible.

Many warning lights are self-explanatory: when the dispenser icon is lit, it means refueling. But some of the many lights are also quite cryptic and can unsettle motorists if they continue to glow after the
engine starts or flashing while driving. After engine start all should go out. If a lamp continues to burn or remains lit while driving, there may be problems. Not all symbols are common to all manufacturers.

The six main warning lights
Basically: A yellow or red lamp means fault or defect. These are the six main control lights that you should stop and contact a workshop:

ABS indicator light. The anti-lock braking system is disturbed, worse braking effect and blocking are possible.

The ABS (Anti-lock Braking System) prevents the wheels from locking during braking so that braking and steering is possible at the same time and the braking distance is shortened.

• Meaning / danger:ABS lights up (red or yellow): Fault, eg defective components (sensors, control units) or mechanical faults. Worse braking effect and blocking are possible.

• What to do? Avoid dangerous situations, keep safety distance; Visit the workshop.

Airbag warning light. Airbags, seatbelt pretensioners or other passive safety systems may not work properly here.

• Meaning / danger:malfunction of the airbag, of the belt tensioner or other safety devices. Attention: It may also be simple that the (passenger) airbag is deactivated, this is necessary if baby carriers are attached to the front seat. The reactivation is then sometimes forgotten.
• What to do? Activate passenger airbag (works with many cars with a small rotary switch in the glove box). In case of failure: consult the workshop.

The Electronic Stability Program (ESP) prevents the car from skidding by selectively slowing down individual wheels. The systems may have different names depending on the manufacturer (ESP, ESC, DSC etc.)

Meaning / danger:Lamp flashes: The ESP is currently intervening (eg because you drive too fast around the bend). Lamp is lit: ESP is off or there is a problem. In the event of a brake failure, ESP and brake warning lights may also be present together.

What to do? Adapt the driving style to the road situation. If ESP off: Turn on again (usually when the motor is restarted automatically or by pressing the ESP key if present). If the lamp stays on: avoid dangerous situations, visit the workshop in a timely manner.

Transmission malfunction
-Battery : The generator provides too little energy, the battery is not charged.

-Brake control lamp : It is possible that only the handbrake is still applied. If the lamp lights up while driving, it may also indicate defective brakes or too little brake fluid.

Meaning / danger:The generator supplies too little energy, which is why the control lamp lights up due to the potential difference. Result: The battery is not charging.

What to do? You can help yourself with start problems due to low batteries ( read more in the Battery Guide). In case of defective batteries or generator problems you should visit the workshop in a timely manner.

Engine warning light : Here, for example, the engine control system may be defective or the exhaust system is disturbed. Sometimes the car just runs in a emergency program.

Oil pressure :
Here you should stop immediately and check the oil level. Because when the lamp is lit, the oil pressure is too low - it threatens a capital engine damage, if you just continue driving.

-Distance warner / ACC
Many modern cars are equipped with radar systems used for distance warning and emergency brake assist as well as automatic distance control (ACC). In case of problems, one or more warning lights will light up and there will be a message in the on-board computer.

• Meaning / danger: One or more systems will not work (possibly temporarily, because heavy rain or slush disturbs the sensor). This means that distance warning as well as distance control and cruise control are not available.

• What to do? In snow / ice: Drive to the nearest parking lot and clean the body parts in front of the radar sensor (the sensor is often located behind the brand logo or at / below the radiator grille). If the defect is not affected by weather, consult the workshop; Observe notes in the operating instructions.

Meaning / danger: The cooling water temperature is too high or the level is too low. Possible causes: Loss of cooling water (leaky radiator, radiator hoses, expansion tank ...), defective V-belt (water pump is no longer driven) etc.

What to do? If possible, top up the coolant provided for the vehicle (normal water should only be topped up in an emergency), visit the workshop in a timely manner.


The diesel additive AdBlue is required for many modern diesel cars for exhaust gas purification.

• Meaning / danger: AdBlue must be topped up. However, this is indicated long before by maintenance instructions. According to the automaker, the vehicle can not be started when the AdBlue tank is empty, since otherwise the correct exhaust gas cleaning is not possible.

• What to do? Refill AdBlue in time, during the inspection in the workshop or at the gas station.

If a yellow or red light flashes or lights up while driving, many drivers are insecure. Which lights mean what, when should you stop immediately or in the workshop? An overview.
Many warning lights are self-explanatory: when the dispenser icon is lit, it means refueling. But some of the many lights are also quite cryptic and can unsettle motorists if they continue to glow after the engine starts or flashing while driving.

Warning lights: green, yellow or red?

There are a few general rules for warning lights:

-A green light indicates the functionality or readiness of a system.
-Yellow or red means fault or defect.
-The symbols and meanings of the warning lights may vary from manufacturer to manufacturer. Therefore always look into the operating instructions, warning lamps are usually described in a separate chapter ("Troubleshooting" or similar).