Introduction: OBD2 Ultra Slim Extender Mod

This project was born for a simple reason: use a obd2 bluetooth adapter without removing the OBD\fuse cover of my Hyundai Ioniq (in my case). As showed in the picture, with this extender you can keep the ELM237 and the extender inside the fuse box, so when the cover is closed everything is out of view. And now, without further ado, let's start!

Step 1: What Do You Need


-OBD extender, I got from Amazon 7,50€

- compatible OBD2 bluetooth adapter like ELM237 2,59€ from Aliexpress

- at least 5 flat pins

- super glue (OPTIONAL epoxy glue)


- weldering iron + tin

- 3D Printer + ABS filament.

- multimeter.

- tweezers and cutter.

Step 2: Procedure

1- Download and print the ultrathin connector from my thingiverse page
I suggest to print it using ABS filament, in the car the temperature may reach 70°C and PLA could melt.

2- Cut the extender near the male OBD2 connector and remove the sheath, you need to keep the wires of pins 4, 5, 6, 14, 16 and remove the others. Use a multimeter to find the right wires.

If you have the same extender as I do check the photo for colour and position.

NOTE: pin 4 and 5 are shorted (they are both GND).

3- Bend the flat pins 90° and weld the wires.

4- To keep the pins in position connect them into the other side of cable (the female connector) and use a little bit of epoxy glue; alternatively you can close the connector using super glue but in this second way the pins will be not very stable, so pay more attention when attaching the connector in the car.

Step 3: Power ON-OFF OBD2

Seems that in my car (hyundai Ioniq) the obd port is always powered, so it can drain the battery of your car if left for a long period. You can buy the extender with an on-off button like this one