Broken Radio, OBD Port also not working

[Tired]

Hi, I recently got vcds and wanted to check my car with it, it showed me that K1 and K2 have no power, I checked the fuses and they all seemed fine.

I read that sometimes it's the diagnostic cable for the radio on aftermarket head units, took out the radio and the cable was already removed. Put it back in and now the radio won't turn on. 

Checked the fuses again and they all seem fine too. So I used a multimeter to check the ISO ports

pin 4 and 8 show 12V with ignition on

Pin 7 and 8 should be battery plus but I get nothing, 0V

What could be the cause for this, I did try jamming the radio when I put it back in because it wouldn't fit with all the cables in the back but how would that kill the battery plus. 

Does anyone have any advice.

[Tired]

Okay, I fixed the radio. 

However I still can't get my hex v2 to get power, my cheapo obd2 Bluetooth adapter does get power but can't connect to the car. 

My assumption is that the Hex V2 adapter is too big and doesn't fully insert into the port, can I remove the port from its position and pull it out slightly? If so how? 

[mk2]

You could add some washers to either push it down or angle it? Does your Hex work in other cars ok?

Lupos use the k line for data with the standard power supply connections. So it should work. The power pins are different lengths to the others, so it is possible that the unit isn't pressed into the socket properly.

[Tired]

Hi, just saw your reply. 

I noticed I was looking at the port upside down so I checked again with a multimeter and the respective pins on the port get power, I plugged the vcds Scanner into my mercedes and it got power there so it's not the scanner that's broken. Today I tried grinding down the plastic housing near the pins, so the pins can get in deeper but that also didn't work. I tried an OBD to OBD extension cable and that also didn't work. I can't seem to get any power to the vcds Scanner on the lupo.

 

My cheapo Bluetooth scanner is at least getting power even if I can't read the car with it 

Edited July 11, 2025 by Tired

[Tired]

I also just tested the hex v2 on my mercedes again with and without the extension cable. both times I was able to read codes

[Tired]

I used a multimeter to measure Pin 4 and 16 and Pin 4 and 7 using the obd extension

ignition on

4 and 16 is 12.5V

4 and 7 is 10.4V

Engine running

4 and 16 is 13.8V

4 and 7 is 12.5V

I simply cannot understand why it's not working with this car, but works with other cars. is there some other pin that I'm supposed to check

[mk2]

Merc is probably different and doesn't use the old K line from the 90's?  Have you tried changing protocol?

[Tired]

Yea the merc is a 2013 C class, but the device gets power from that even with the ignition off, because of the battery 12V pin. 

If you mean selecting KWP 2000 inside vcds then yea I tried that, but the problem is the device not getting any power form the car at all for some reason.

if I at least got power but was unable to connect to the ecu, I'd have more options.

I think I'll just have to give up and go to a shop. Though all I wanted to do was scan for codes and adjust my xenons after I got a new xenon level sensor and new bulbs

[mk2]

Have you tried a different OBD2 lead? I have a few and only one (!!!) works on my Lupos and with VCDS... Same symptoms, looks like no power. I've never investigated why. 

[Tired]

I guess I could try buying a KKL cable. A damage appraiser was able to scan the car a couple months ago so that might be it

Edited July 13, 2025 by Tired

[Tired]

KKL Cable and VAG com worked, thanks for the tip!