2017 Seat Leon front assist fail light - MOT fail?

[hermes]

Even when the system was working it didn't do anything.

Now I have a yellow light on and 'front assist not available' - MOT failure?

Looks like 10% of the value of the car to fix the light.

[BertBert]

What is front assist?

[georgeyboy12345]

Just plug a OBD code reader in and clear it.

[spreadsheet monkey]

Front Assist is the collision detection system, with automatic emergency braking (AEB). Potential MOT failure if there is a warning light indicating a system malfunction

https://www.gov.uk/guidance/mot-inspection-manual-...

1.7 You must inspect the warning lamp operation on vehicles with an electronically controlled braking system.

Defect reference Defect Category
(a) Warning device not working Major
(b) Warning device shows system malfunction Major

[snotrag]

hermes said:

Even when the system was working it didn't do anything.

Now I have a yellow light on and 'front assist not available' - MOT failure?

Looks like 10% of the value of the car to fix the light.

MOT fail as above.

You only realise its doing something when you are 6 inches from having a front end collision and it jams the brake on harder than a human brain can even comprehend and your head nearly snaps off.

Check the sensor isnt dirty first.

Other than that, they often fail becuase the housing gets damaged from either nudging things when parking or from a bird strike.

If its been nudged or on the wonk, it can be re-adjusted and recalibrated.

Edited by snotrag on Monday 16th February 11:52

[SuperPav]

if you can get to someone with VAG diagnostics (VCDS or similar) it'll tell you if one of the sensors is faulty...

I had a Tiguan that popped a parking sensor connector out when I hit a tree branch on the road, and that showed the same fault. VCDS showed which parking sensor wasn't working. In my case it was just a connector, but even if you need to replace one they're like £15 off ebay. Then just clear the codes.

Front assist uses parking sensors and the main forward facing camera, so it'll only really be one of those two, unless there's a bigger chassis system error, in which case you'd also expect TPMS/ABS lights on.

[Deerfoot]

snotrag said:

Check the sensor isnt dirty first.

My wife's old Ateca regularly used to throw up this fault after driving on Salisbury plain while walking the dog, a quick clean and it cleared. Must have happened over a dozen times during our ownership.

[Robertb]

I'd ask the MOT station (or the kindly PH resident MOT tester via the "ask an MOT tester anything" thread). AEB only became a legal requirement in 2022.

I had a "blind spot assist not operational" and "lane keep assist not operational" warning on my 2014 Mercedes and this is not part of the test. Wasnt even noted as advisory.

[Antony Moxey]

It'll be because you've been through a deep puddle or a lot of surface water and it's got misaligned. I currently have exactly the same on my 2017 Leon, although it corrected itself and has now become misaligned again. Apparently it might be able to be clipped back into place (it sits behind the fag packet square plastic cover in the lower grill), or it might need a new unit fitting. Either way, my Seat DP brother-in-law said to not worry about it for now (unless I wanted to worry about it now) and they'll sort it come MOT time.

[Jazoli]

SuperPav said:

if you can get to someone with VAG diagnostics (VCDS or similar) it'll tell you if one of the sensors is faulty...

I had a Tiguan that popped a parking sensor connector out when I hit a tree branch on the road, and that showed the same fault. VCDS showed which parking sensor wasn't working. In my case it was just a connector, but even if you need to replace one they're like £15 off ebay. Then just clear the codes.

Front assist uses parking sensors and the main forward facing camera, so it'll only really be one of those two, unless there's a bigger chassis system error, in which case you'd also expect TPMS/ABS lights on.

Not on a 2017 Leon it doesn't, It has its own radar sensor that is also linked to the adaptive cruise control.

I think you are confusing parking assist with collision assist.

I'm fairly certain it isn't an MOT fail currently.

[spreadsheet monkey]

Robertb said:

I'd ask the MOT station (or the kindly PH resident MOT tester via the "ask an MOT tester anything" thread). AEB only became a legal requirement in 2022.

I had a "blind spot assist not operational" and "lane keep assist not operational" warning on my 2014 Mercedes and this is not part of the test. Wasnt even noted as advisory.

Blind Spot Assist and Lane Keep Assist are not part of the test as they don't relate to brakes.

But surely any kind of AEB has to be part of the "electronically controlled braking system" as defined in part 1.7 of the MOT rules. If there's a warning light or warning message, then that's a major defect.

Maybe if you have a friendly MOT station you might get away with it

[Robertb]

spreadsheet monkey said:

Robertb said:

I'd ask the MOT station (or the kindly PH resident MOT tester via the "ask an MOT tester anything" thread). AEB only became a legal requirement in 2022.

I had a "blind spot assist not operational" and "lane keep assist not operational" warning on my 2014 Mercedes and this is not part of the test. Wasnt even noted as advisory.

Blind Spot Assist and Lane Keep Assist are not part of the test as they don't relate to brakes.

But surely any kind of AEB has to be part of the "electronically controlled braking system" as defined in part 1.7 of the MOT rules. If there's a warning light or warning message, then that's a major defect.

Maybe if you have a friendly MOT station you might get away with it

Wouldnt that refer to a 'brake by wire' system?

Front assist is not a mandatory safety system in this case, as its built prior to 2022.

[POIDH]

My 2017 Fabia ADAS "front assist" is similarly crap at detecting things that matter, and also has spent last few months refusing to work.

The good news is after tracking down somewhere nearby that actually would touch ADAS systems and has the kit, it transpires it just needs new calibration. Chap who runs the business says that over half of the issues are just down to needing recalibrating - he thinks the state of our roads is rattling these things too much and causing the issue. The garage got me to drop in so they can do a scan - and found nothing. So booked in to calibrate.

I am hoping for a bill of around £180 to fix. Will let you know on Wednesday.

[hermes]

POIDH said:

My 2017 Fabia ADAS "front assist" is similarly crap at detecting things that matter, and also has spent last few months refusing to work.

The good news is after tracking down somewhere nearby that actually would touch ADAS systems and has the kit, it transpires it just needs new calibration. Chap who runs the business says that over half of the issues are just down to needing recalibrating - he thinks the state of our roads is rattling these things too much and causing the issue. The garage got me to drop in so they can do a scan - and found nothing. So booked in to calibrate.

I am hoping for a bill of around £180 to fix. Will let you know on Wednesday.

How did you get on?

My OBD shows no fault codes, but the local garage/MOT place unsurprisingly says it is an MOT failure, and I will have to pay them for a code read before they look at anything else.

[hermes]

So I’ve now paid the garage to tell me what I told them, that the ADAS is out of alignment, and we’re back to the beginning, which is why is this an MOT fail on a 2017 car with no auto braking.

Going to put it in for MOT at my regular place, and see what happens….