I have a 2010 Fabia 1.2 and the ODB port isn't playing ball. Tried 2 different scanners and they both fail to auth with the ECU. I initially thought it might be a bad fuse so I replaced num 22, didnt change a thing. Slipped the port out of the dash and made sure that the wires are fully seated in the connector, no change. I've tried with electrics on and also engine on, doesn't make a difference.

Does anybody have any suggestions on what to look for next?

Check the voltage at battery. If its too low then OBD sometimes won't work and make sure that the fuse is making good contact. It should be OBD2 but as its can bus maybe older scanners won't work?

Alasdair

Do you have an aftermarket radio? like an android unit? If yes, it could be that the head unit is connected via can and taking priority of the can system and not allowing the obd reader to connect to the can line. This happened to me on a 2013 fabia while i was tuning the ecu and I wasn't able to connect via obd, disconnected the head unit and everything was working.

On 28/10/2025 at 16:08, Alasdair1 said:

Check the voltage at battery. If its too low then OBD sometimes won't work and make sure that the fuse is making good contact. It should be OBD2 but as its can bus maybe older scanners won't work?

Alasdair

I've tried 2 different scanners and they both failed to connect. Haven't checked the battery but I do have a multimeter in a box I can dig out!

On 29/10/2025 at 09:36, Jack25 said:

Do you have an aftermarket radio? like an android unit? If yes, it could be that the head unit is connected via can and taking priority of the can system and not allowing the obd reader to connect to the can line. This happened to me on a 2013 fabia while i was tuning the ecu and I wasn't able to connect via obd, disconnected the head unit and everything was working.

Nope it's the bog-standard CD player jobby, nothing aftermarket in the entire car!

I could disconnect the fuse for the radio and see if that makes a difference?

26 minutes ago, cjmason88 said:

Nope it's the bog-standard CD player jobby, nothing aftermarket in the entire car!

I could disconnect the fuse for the radio and see if that makes a difference?

ok, you can try to disconnect the battery for like 10-15 minute connect it again and try (i don't it will solve but worth a try) more effective look behind the obd port for broken or sliced wire

Might be that the obd port isnt connecting to one of the pins on the reader. Had problem years ago and the obd socket wasnt making proper contact with the pins in the reader cable. In my case there was dirt/corosion in the cars OBD port. I used a pin to clean and made sure the spring connectors were tight and it came back to life. Check that your actually getting 12v to socket in car and also the earth is good. Sorry not sure what pins are which think pin 16 is 12v supply and 4and5 are earths.

42 minutes ago, Jack25 said:

ok, you can try to disconnect the battery for like 10-15 minute connect it again and try (i don't it will solve but worth a try) more effective look behind the obd port for broken or sliced wire

I had a look the other day, all wires look fine and I made sure they were all pressed home as much as I could.

42 minutes ago, Alasdair1 said:

Might be that the obd port isnt connecting to one of the pins on the reader. Had problem years ago and the obd socket wasnt making proper contact with the pins in the reader cable. In my case there was dirt/corosion in the cars OBD port. I used a pin to clean and made sure the spring connectors were tight and it came back to life. Check that your actually getting 12v to socket in car and also the earth is good. Sorry not sure what pins are which think pin 16 is 12v supply and 4and5 are earths.

I will check the readouts when I dig my multimeter out.

Hope its something simple. Old car electrics were bad enough but new ECU based stuff is getting way beyond me. Check all the fuses related to ECU as well. On my sons MK1 there are a few that are linked to ECU. Car could be going through a process before connecting and getting stuck.

Used this but not sure how accurate it is but was fine for my sons to find fuses etc. His main strip fuse for brake/ABS had cracked.

https://www.startmycar.com/gb/skoda/fabia/info/fusebox

Alasdair

Hi, I've had fabia 2009 level 1 trim for almost year and half now and been experiencing similar issues.

First of all my obd port doesn't work properly with cheap scanner also well known apps powered by obd2 scanner.

I also occasionally get abs fault popping up, but it happens at random times, sometimes nothing for weeks. Could you explain which fuse to look for? Is it by the battery?

ABS I think on my sons mk1 is a strip fuse in front of battery. His are individual but I think later models had a sealed fuse pack. There prone to cracking but difficult to see any cracks until removed. His ABS brake warning lights includiing warning chime(bloody loud) used to come on randomly. The fuse had a hairline crack that broke contact from time to time. It could also be a dodgy ABS sensor or wiring. Difficult to work out when the scanner wont connect.

Is there anyway to find out ? Obd doesn't seem to connect even it has a port.

As mentioned near start of post do you have an aftermarket radio? Some can interfere with OBD connection. As for ABS sensors the only way is to scan car to find out which one unless you replace all four but it could also be a failed sensor ring in bearing or bearing itself. Check the wiring to each sensor and the condition of the connecting plug plus feel for roughness in bearings.

Alasdair

Well to flog the dead horse somewhat, the ABS light pinged up today (first time ever). Scanner doesn't connect still.

What I HAVE noticed though is that my fuse strip next to the ODB port seems to be the wrong way round to the diagram on the back of the panel (and the diagram link above) - the fatter fuses are to the left and the smaller ones to the right (which doesnt correlate to the diagram). Is this potentially the reason why nothing is working (because someone in the past has 'fiddled' and put it back incorrectly)?

No, you just have a RHD car instead of the LHD the manual pictures.

Fuesbox is just rotated 180°, in the factory.

8 minutes ago, Breezy_Pete said:

No, you just have a RHD car instead of the LHD the manual pictures.

Fuesbox is just rotated 180°, in the factory.

Well that seems a bit stupid tbh! You would think they would put a RHD diagram on the cover...

1 minute ago, Breezy_Pete said:

Thank you!

Yes, it causes owners in RHD countries plenty of head-scratching.

Cost saving.