NCT and On Board Diagnostics

Sun in Capri

Hello, First NCT on a Fiat Panda. It passed but it got an advisory relating to OBD (on board diagnostics). It said unable to access OBD. Unfortunately I only saw this when I left the test centre so didn't question it. Does anyone know if this means they couldn't find the place to plug in for testing OBD or what might it mean?

Thanks.

Oops!

It's nothing to worry about, your car has passed the test..... Happy motoring.

Sun in Capri

So next NCT what will happen if not sorted?

mikewest

Until the rules change (maybe never) to make it a fail then nothing will happen.

Arnout

I got a pass advisory as well on my wife's Skoda, the advisory being on two OBD messages. One was tyre pressure (apparently still stored in the OBD even though the puncture was dealt with a while ago and the error message on the dashboard reset) and the other one an 'undervoltage on the steering sensor'. Since I was at the garage today to get the tyres of my own car replaced I asked them what that means, and apparently that's also a symptom of an underinflated tyre. So it just needs resetting at some point, even though the related issue is no longer there.

Gotta love computers these days, and it's good that they don't fail a car on something like that. Although it does leave me wondering why the garage doesn't clear out the errors in the OBD when they fix a tyre...

creedp

https://www.boards.ie/discussion/comment/120148582#Comment_120148582

Very few people go to an actual garage to repair punctures / replace tyres. Given the supposed sophistication of the computerised systems it's strange that these systems can identify that a tyre is under inflated but for some reason cant process the fact that the tyre has been reinflated

Arnout

What do they do then, fix them themselves? I do that on a bicycle, on a car it's a bit farfetched for me...

And yes I reinflated the tyres in question on a regular basis, but I didn't want to keep doing that. It's easier if they just keep the air in.

I do agree that it's strange that those sensors only work one way.

creedp

https://www.boards.ie/discussion/comment/120149556#Comment_120149556

I meant they go to a tyre shop that barely tighten the wheel nuts at times and certainly wont be accessing the cars on board computer, even if they had the necessary hardware/software for each possible car brand they work on

Arnout

Oh, right, now I get what you mean.

Well our Skoda had a few tyre issues, as it turned out. I first went to a Bestdrive with a deflating left rear tyre. Turned out the valve leaked, so they replaced that. Still issues, went back, and the tyre itself also had a puncture! So they ended up replacing it (because the puncture was too close to the side). And yes I had seen the soap bubbling myself as well, the valve really did leak, so I don't blame them for not finding the puncture the first time.

Then the car started complaining about both right tyres every few weeks. Went there again, they fobbed me off saying I had to see if the tyres would stay inflated this time. Even though I was very clear that I had already reinflated them a couple of times myself.

Found a different garage, accross the road from work, so just dropped the car off there and picked it up at the end of the day (at least I don't waste time driving back and forth to Bestdrive). Both wheels had corroded a bit and that caused them to leak past the valves. So he fixed that, two months ago now I think, and to this day I haven't had to reinflate the tyres.

But he didn't reset the OBD and he was the one who explained the advisories on the NCT certificate to me...

zg3409

OBD is a new thing and no one can fail at the moment. It's intended long term to check for faults that may not be visible on the dash such as some emissions failures.

It's been in USA for a long time and in many places they don't test emissions gasses instead ask the computer are emissions ok.

Some unscrupulous people replace the old socket with a fake one that returns all ok during the test. It's common for airbag or modified boy racer engines to have a fake odb port fitted.

For now it's not an issue but may be a problem for example airbag faults and some things need a minimum number of miles driven since computer was last reset which can cause problems for cars just repaired or serviced at a dealer. Computer needs a minimum distance to determine if engine is ok.

coylemj

You can read all about OBD and the NCT at the last item (#24 'What is OBD Testing?') in their FAQs here .....

https://www.ncts.ie/1123/

They claim that....

From early 2022, should certain error codes be detected, they will constitute a reason for failure in the NCT and an NCT certificate will not be issued until the items are rectified and a pass result is achieved.

odyssey06

We're still no closer to figuring out what "unable to access OBD" means?

The OBD wasn't found?

The OBD couldn't be accessed ... could it be that the glove compartment wasn't empty???

The OBD was accessed but system was dead?

This port is usually located under the steering wheel but may also be found in the glove compartment of the vehicle.

http://www.autotrade.ie/index.php/new-obd-checks-to-be-introduced-to-nct-from-monday/58106

User1998

https://www.boards.ie/discussion/comment/120151827#Comment_120151827

It’s fairly self explanatory, it just means the OBD couldn’t be accessed. So like you said, it could be broken, covered up, disconnected, etc.

creedp

https://www.boards.ie/discussion/comment/120153513#Comment_120153513

I'm not sure how obvious it is as in my case the OBD was clearly visible beside the steering column and it works as I use it all the time but I still got `unable to access OBD' at last test. Maybe testers use it as an excuse to not be bothered with it at present as not mandatory