Contained in this section are many of the dashboard warning lights, engine management lights and fault symbols associated with the Audi A4.
Each warning or information symbol is similar or identical to those found on the Audi A4 dashboard and included is the meaning of the light symbol. Dashboard lights may vary depending on the version of the Audi A4 and the country in which it was manufactured.
As a general rule the colour of the illuminated symbol illustrates the severity of the issue. Symbols that are red once illuminated indicate an issue that required immediate attention. Orange will typically indicate a less urgent issue, for example a vehicle service required.
Other symbol colours such as blue and green provide the driver with information such as lights and indicators. Flashing warning lights inform the driver of an urgent issue.
Engine management light
The light should illuminate with the ignition turned on and go out once the engine has started. If the light remains on or flashes whilst driving, take your vehicle to an authorised Audi technician. Light may indicate an issue with emissions control or the catalytic converter. The Electronic Power Control (EPC) is an alternative to the engine management light as seen above used on Audi cars.
Audi Hold Assist light
This circle in brackets symbol is a system that monitors the Audi Hold Assist function. Audi Hold Assist helps to keep the vehicle stationary whilst the engine is running. Example can be whilst stopping on a hill at traffic lights. When the light is on, the system is activated and you do not need to keep your foot on the brake.
Low battery charge
If the battery power drops to a level where problems may be encountered when starting the engine, the low battery power charge light will illuminate. If the light comes on for a period of time whilst driving and goes out, it means the engine has sufficiently charged the battery. If the light comes on and does not go out whilst driving, the battery power is not being sufficiently regenerated. Starting reliability issues may arise. Consult an authorised Audi technician.
Dynamic steering light
Light illuminates with ignition activation and goes out a few second after. If the warning light stays on after the engine has started, it indicates a malfunction within the system. Driving can continue at a reduced speed until seen by a qualified Audi Technician. Steering may feel unresponsive and heavy and may also the steering wheel may not be central when driving in a straight line.
Airbag system light
This system monitors the airbag and seat belt tensioner system. The dashboard warning light should go on when the ignition is activated and go off after a few seconds. If the light does not go out or illuminates whilst driving, it indicates a malfunction within the system. If the light does not illuminate when the ignition is turned on, it also signifies a malfunction. Failure to get the fault remedied may result in airbag or seat belt tensioner failure. For further information about airbags and possible faults, see why is the airbag light on?
Lane assist active
This system warns you if your vehicle is about to cross lane markings. The lane assist dashboard warning light is illuminated green to signify it is active. The symbol is illuminated amber to signify the system is inactive.
Cooling system fault
This system monitors the engine temperature. If the cooling system fault light illuminates whilst driving, stop the engine as soon as is safely possible. This may indicate the engine is overheating. Wait till the engine has cooled down and check engine coolant levels. If light remains on, seek assistance from a qualified Audi workshop. See what is engine coolant and how to check engine coolant for further details.
Anti-lock brakes light
The anti-lock brakes (ABS) light illuminates for a few seconds with the ignition being switched on and extinguishes once it has run through the automatic test. Test also monitors the electronic differential lock (EDL). If the light does not illuminate with the ignition, extinguish after a few seconds or comes on whilst driving, there is a fault. Normal braking is not effected, though the ABS will not function. See the Anti-Lock Braking System guide for understanding what ABS is and how it works.
Parking brake light
When the vehicle has been stationary for an extended period of time, Audi Hold Assist will detect this and apply the parking brake. When this happens the light will change from green (see left) to red. If the light begins to flash, the parking brake may not be strong enough to hold the vehicle. This may be due to worn or overheated brakes. A fault with the system is indicated on the dashboard by a yellow symbol in conjunction with the parking brake symbol.
Electronic Stability Program
Yellow circle, with triangle and exclamation mark – The Electronic Stability Program (ESP) dashboard light flashes if the ESP or traction control is activated whilst driving. If ESP or traction control has been switched off, it will light up continuously. If ESP or traction control is not turned off and the warning light illuminates continuously, it indicates a problem and malfunction with either ESP or traction control.
Brake warning light
Red circle containing a red exclamation mark – If this light illuminates whilst driving, it either indicates that the parking brake is engaged or that there is a fault within the braking system. For further information, see why is the brake light on in my car?
Tyre Pressure Warning Light
Tyre containing yellow exclamation point – Tyre pressures should be corrected as soon as possible if the pressure is too low. See tyre legal limit for information on having too high and too low pressure in tyres. If this symbol flashes for around 1 minute and remains illuminated, it signifies a fault within the system. If you are experiencing problems, see tyre pressure warning light keeps coming on.
Engine oil pressure
The system monitors the engine oil pressure. If this symbol illuminates, it signifies low engine oil pressure. Switch off the engine as soon as safely possible. Engine oil should be checked and if light remains on, seek assistance from a qualified Audi workshop as soon as possible. See how to check engine oil for further information.
Brake pads worn light
When this symbol illuminates it signifies that the brake pads on the vehicle are worn. Worn brake pads reduce effective braking and increase braking distances. Seek assistance from a qualified workshop to change brake pads.