Daytime running lights — retrofitting, installation, coding

Here you will find useful information and important tips relating to the daytime running lights in vehicles.

Daytime running lights increase safety in road traffic. This is why they are already fitted as standard in newer vehicles. On this page, discover the advantages of daytime running lights compared to low beam lights. Here you will also find tips for selecting retrofit sets which are legally compliant and how to install them correctly. Using the example of coding the lighting function, you will also discover the possibilities for customisation provided by modern vehicle electrical systems.

Important safety note
The following technical information and practical tips have been compiled by HELLA in order to provide professional support to vehicle workshops in their work. The information provided on this website is intended for use by suitably qualified personnel only.


The primary function of the daytime running lights is to make a vehicle more visible to other road users. Particularly in situations where the lighting conditions change, for example when driving through a section of forest, this is particularly important.


Another advantage is that other road users gain more response time, as they can see a vehicle more clearly and quickly. The fact that the daytime running lights are automatically activated when the ignition is turned on is another convenient advantage. It is therefore impossible to forget to turn them on.


Summary of the advantages:

  • Better perception of the vehicle by other road users
  • More time for other road users to react
  • The daytime running lights switch on automatically.


  • Increased fuel consumption as all headlamps and lamps are always switched on: Lighting is expensive as the headlamps and rear lamps require electricity and therefore use fuel! For a normal car with a gasoline engine, this is approximately 0.207 litres in increased consumption per 100 kilometers when the lights are switched on. Based on a mileage of 30,000 km per year, this approximately adds up to an extra 60 litres. As a result of this, the exhaust emissions of course increase accordingly too.
  • The replacement rate of light sources is significantly increased: Switching the lights on permanently increases the wear and tear of bulbs. The service life of standard versions of H7 and H4 halogen bulbs (no + 50% or long-life bulbs) lies between 550 and 700 hours. In the event of continual operation, the replacement rate of the bulbs would be significantly increased. An LED daytime running light, on the other hand, has a service life of 10,000 hours and usually lasts as long as the car.
  • Besides the material costs, there are the sometimes considerable costs of the replacement of the light source. In some cars, the bulb replacement takes a great deal of effort, as battery, air filter housing, headlamps, etc. must be removed first.
  • The warning effect of low beam lights is smaller than that of special daytime running lights. Low beam lights typically are set to provide an optimal lighting of the road in darkness. The emitted light "descends" evenly, in order to avoid dazzling oncoming traffic. Daytime running lights, on the other hand, are designed to achieve an optimal and early perception of the car during the day. Their light intensity is limited (2 Lux at a distance of 25 m) so that the emitted light is not perceived as glare.

The market offers installation kits with electronic components that only turn on the low beam lights. Is that an alternative to daytime running lights?

Compared to driving without lights, this may be a step in the right direction. However, as explained above, daytime running lights offer clearly superior visibility and energy savings. Some of these electronic kits also dim the low beam, in the case of one manufacturer even by about 50%. This means that the luminous flux, i.e. the total volume of light that is output by a light source, is reduced so much that it falls below the required minimum value. This is absolutely prohibited by law!


This is because headlamps receive their type approval for form, light source, and function. Daytime running light generated with the aid of electronics thus means an additional lighting function which was not considered during type approval. Therefore, the headlamp automatically loses its approval!

Approval for road traffic

Generally, daytime running lights must be approved for road traffic. To obtain this, they must therefore fulfil the specifications according to ECE-R87. Once the light passes the so-called type approval, the approval is granted. Generally, the approval mark can be found on the lens or the housing.

2578 Approval number


E1 Marking according to ECE "E". The "E" is followed by the code of the country that granted the type approval. (In this case, it was granted in Germany.)


RL Marking as daytime running light


 Some vendors advertise their often very compact, rod-shaped LED lights as daytime running lights. It is only in the small print that they mention that these are not approved as daytime running lights according to ECE-R87.


The reasons for that might be:

  • The illuminating surface is smaller than 25 cm2
  • Light values are too low (at the level of a position light)


These lamps must not be employed as daytime running lights. At best, they may be used as position lights – if they are approved for that.


Legislation allows for various installation options. However, there are predefined distances and beam angles that must be adhered to.


  • * When used as a position light, the minimum permitted installation height is 350 mm and the lights must not be more than 400 mm from the outer edge of the vehicle.
  • ** For vehicles with a width < 1300 mm, the distance must be at least 400 mm.
  • *** When used as a position light max. 400 mm. If the light is only used for the daytime running light function, this restriction does not apply.
  • When using a daytime running light as a position light, the standard position light must be permanently deactivated in accordance with ECE-R48.


For more information on legal stipulations and installation regulations, please refer to the Internet or a qualified garage. Please refer to the assembly instructions for more detailed information.


Assembly instructions LEDayLine 15/30

Skoda Octavia manufactured in 1999 – "LEDayLine" LED daytime running lights.


Daytime running lights make a great contribution to safety in road traffic. Law makers are also convinced that this is the case. For this reason, this lighting function is obligatory for all new vehicles entering the market from February 2011 onwards. The market offers a wealth of retrofit solutions for vehicles which do not have daytime running lights fitted as standard.


There are few alternatives for electrical connection, despite the differences in terms of design, light sources, and attachment. With many manufacturers, the lights are connected with terminal 15 (switched plus, often also known as ignition plus), terminal 58 (position light) and terminal 31 (ground). While the connection of terminals 58 and 31 is unproblematic in most cases, the situation can be different for terminal 15.


In modern vehicles, there is a lack of connection possibilities under the hood e.g. fuses of other consumers connected to switched plus. In such cases, a cable has to be routed to the vehicle interior. There is usually a suitable connection possibility in the fuse box there. In many vehicles of the brands Audi, Seat, Skoda, and VW, daytime running lights can be triggered via the light switch.

Proceed as follows for the electrical connection:

Connect cable for terminal 31

Connect the cable for terminal 31 (ground) to a suitable spot on the body or directly to the battery.

Do not connect the cable for terminal 58 to the position light cable

The cable for terminal 58 does not have to be connected to the position light cable on the headlamp. This function is taken over later by the light switch.

Route cable for terminal 15

Route the cable for terminal 15 to a suitable spot on the interior.

Unlock and remove light switch

Unlock the light switch and remove it from the cockpit trim. To do this, first push the rotary switch in, and then turn it clockwise slightly.

Remove any side cockpit trim

In some vehicles (e.g. VW Sharan or Seat Alhambra) the switch cannot be pulled completely out of the cockpit together with the cable connection. In this case, the side cockpit trim has to be dismantled first, so that the plug connection is accessible from there.

Loosen plug connection

Loosen the plug connection from the switch.

Contact for daytime running lights

There is a contact for the daytime running lights on the switch.

Contact socket is not fitted with a crimp contact

The matching contact socket in the connector is not usually fitted with a crimp contact.

Connect cable for terminal 15 there

With the aid of a crimp contact (HELLA no. 8KW 863 934-003) the cable can thus be connected to terminal 15 there. A fuse holder (8JD 743 557-021) with a 3 amp fuse should be fitted upstream, however.

Install the parts in reverse order

Install the removed parts in reverse order.

When the ignition is switched on, the daytime running lights are switched on automatically

When the ignition is switched on, the daytime running lights are switched on automatically. When the light switch is actuated (position light or low beam), the lamps go off automatically.

Here is a list of the vehicles in which this type of connection is possible. The list does not claim to be complete.

Audi A3 (8L) Model year 09/96 – 05/03
Audi A (8P1) Model year 05/03 –
Audi A3 Sportback (8PA) Model year 09/04 –
Audi A4 sedan (8E2, B6) Model year 11/00 – 12/04
Audi A4 Avant (8E5, B6) Model year 04/01 – 12/04
Audi A4 convertible (8H7, 8HE) Model year 04/02 –
Audi A4 sedan (8K2) Model year 11/07 –
Audi A4 Avant (8K5) Model year 04/08 –
Audi A6 sedan (4B, C5) Model year 01/95 – 01/05
Audi A6 Avant (4B, C5) Model year 11/97 – 01/05
Audi A6 sedan (C7) Model year 05/04 – 04/11
Seat Alhambra (7V8, 7V9) Model year 10/97 – 06/10
Skoda Fabia (7V8, 7V9) Model year 08/98 – 03/08
Skoda Oktavia (1U2) Model year 09/96 –
Skoda Oktavia station wagon (1U5) Model year 07/98 –
Skoda Oktavia (1Z3) Model year 02/04 –
Skoda Oktavia station wagon (1Z5) Model year 02/04 –
VW Bora (1J2) Model year 09/98 – 05/05
VW Golf IV (1J1) Model year 08/97 – 06/05
VW Golf IV Variant (1J1) Model year 05/99 – 06/06
VW Lupo (6X1, 6E1) Model year 10/98 – 07/05
VW Passat (3B2) Model year 10/96 – 11/00
VW Passat Variant (3B5) Model year 06/97 – 11/00
VW Passat (3B3) Model year 11/00 – 05/05
VW Passat Variant (3B6) Model year 11/00 – 05/05
VW Polo (9N1,2,3) Model year 10/01 – 03/10
VW New Beetle (9C1, 1C1) Model year 01/98 –
VW Sharan (7M6-7M9) Model year 09/97 – 10/10
VW Transporter 5 (7HA-7EH) Model year 04/03 –


Coding for installation of daytime running lights

Daytime running lights are often already fitted as standard in many newer vehicles. Depending on the vehicle model, however, customers have different wishes concerning the optical design of this lighting function. If customers do not like the optical design, something can be done about it. In many cases, the daytime running light function can be switched off by coding. Again, the Golf VI shall be used as an example for this.


For this purpose, the "long coding" is requested via the menu items Central electrics – Coding. When byte 15 is selected, a list of bits and their functions appears. If the tick is removed from bit 6, the DRL function is deactivated (see Fig. 1). This allows customer wishes related to design and installation location to be implemented.


When daytime running lights are retrofitted, the ventilation slots in the front apron often offer the ideal location. This spot is, however, often already "occupied" by standard fog lamps. But there are daytime running lights available that have almost the same dimensions as fog lamps. Often, customers think one can simply be replaced by the other. But fog lamps are used less often. Daytime running lights using LEDs also have the problem of bulb failure check. Coding can be used to remedy the situation here, too. The Golf VI shall be used as an example again.


For this purpose, the "long coding" is requested via the menu items Central electrics – Coding. When byte 14 is selected, a list of bits and their functions appears. If the tick is removed from bit 0, the fog lamp function is deactivated (Fig. 2).


If the customer would like a cornering light, this is no problem if fog lamps are installed. Simply check the box next to bit 7 and the fog lamps will switch on accordingly in the respective situation.


Professional modification of the lighting technology can even be carried out on modern vehicles through coding. The possibilities always depend on what the manufacturer allows on the coding level, of course, and whether suitable diagnostics testers are available. Experience shows, however, that more and more garages are discovering this possibility for themselves, and can thus fulfil their customers’ wishes.

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