CK Bulb Socket vs. Standard Bulb Socket | Tech Tips

CK Bulb Socket vs. Standard Bulb Socket

CK also known as SCK, SACK, or SRCK like this: 3157CK, 3157SACK, 3157SRCK

Only a handful of vehicles made in certain years, from a few manufacturers use a CK wired socket. Sometimes different car and truck manufacturers will change the type of wiring configuration they will use to power turn signal and brake light bulbs. Normally you would have Positive and Negative terminals on either side of the bulb, but the “CK” type wiring is different. 

A CK/SRCK is wired differently than the usual sockets you see in most Japanese, and American vehicles:


These wire configurations are found on 3157 and 7443 bulbs. The LED bulbs for these applications will have special technical components built into the LED bulbs that allow them to work for either type of socket.

You will find that the GTR Lighting Armor Series LED bulbs work with either standard wiring or CK wiring, while the GTR Lighting Carbide CANBUS LED bulbs are more specific. With the Carbide CANBUS bulbs, you need to identify if you have the standard wiring or the CK type wiring before making your purchase.

The position of the contacts in the socket is the only difference. The bulbs and the sockets look identical – the only way to know the difference is to test with a multimeter!

If you install a non-compatible bulb there’s a possibility it will blow the protection circuit fuse and you will have to replace the fuse and install the correct bulb. Sometimes if you use the wrong bulb it will simply not work correctly, without blowing a fuse – that depends on the vehicle.


How to Identify Your Socket Type

  1. Search on Google or YouTube for vehicle-specific information.

If you are driving a more popular vehicle, chances are someone on the internet has already solved this problem for you. Searching through vehicle-specific information on YouTube, Facebook Groups, or forums will give you may be more exact than the answers we can provide.

  1. Do your own testing!

While the previous point may bring you the answer you need, but it may not be the one you are looking for. We highly recommend you do your own testing in case the information they provided, or it may be possible that the manufacturer of your vehicle changed the socket style from one month of production to the next! There doesn’t seem to be any real indicator as to why one vehicle uses standard style, and another vehicle uses “CK” style sockets…

From our experiences, many TOYOTA vehicles' front turn signal sockets are a CK type. Sometimes, you can even see there are two metal terminals inside the socket connected directly which means they are the shared CK-Style ground terminals. Sometimes you may be able to identify the ground terminal locations from the wires on the back of the socket. A test is still required in order to confirm the type. 

Also, your original bulb will tell you if it is a CK or standard, most CK bulbs will say SRCK on the bulb base.

To do the testing we recommend you use a digital multimeter, but a test light may also work. If you are not a qualified and trained technician we recommend that you hire one to decide which type of LED bulbs to purchase. Please remove all tail light bulbs before testing, otherwise, the filament in the brake circuit will read as a “false ground”.

Here is a list of possibly confirmed vehicles that use CK-style sockets (NOTE: You must test your sockets BEFORE you purchase your new GTR Lighting LED bulbs):

2008-2015 Scion xB brake lights: 7443SRCK

2013-2015 Ford C-MAX outer Brake/taillights: 7443CK

2005-2010 Honda Civic COUPE (not sedan) Front Turn Signals: 3157CK

2005-2013 Toyota Corolla front turn signals: 3157CK

2005-2015 Toyota Tacoma front turn signals: 4157CK

2006-2019 Toyota Tundra front turn signals: 4157CK

2009-2014 Nissan Maxima front turn signals: 3157CK

2004 Acura MDX front turn signals: 3157CK

2005 Nissan Pathfinder front turn signals: 3157CK

2005-2011 Nissan Xterra front turn signals: 3157CK

2002-2007 Toyota Camry front turn signals: 3157CK

2008 Ford Escape front turn signals: 3157CK

2011 Toyota Avalon front turn signals: 3157CK

2013-2015 Honda Accord Coupe front turn signals: 3157CK 

2018-2019 Subaru Crosstrek front turn signals: 7443CK

2018 Land Rover Discovery front turn signals: 7443CK

2012-2014 Acura TL front turn signals: 3157CK

2016-2020 Chevrolet Colorado front turn signals: 7443CK

2013-2018 Chevrolet Equinox front turn signals: 7443CK

2015-2017 Chevrolet Impala front turn signals: 7443CK

2019-2020 Chevrolet Silverado Custom front turn signals: 7443CK

2018-2019 Ford Expedition front turn signals: 7443CK

2019 GMC Canyon front turn signals: 7443CK

2010-2013 Honda Pilot front turn signals: 3157CK

2006-2007 Nissan Frontier front turn signals: 3156CK

2019-2020 Ram 1500 front turn signals: 3157CK

2018-2019 Subaru Impreza front turn signals: 7440CK

2005-2020 Toyota Sienna front turn signals: 7440CK

2008-2012 Toyota Sequoia front turn signals: 3157CK

If you have any more questions about your bulbs, reach out to our customer service team here. We will be able to assist you in all your lighting needs.