Technical ABS not working, but no warning or failure lights...!

[AcidMonkey]

Hi all - new member!

I've just bought a fiat 500 1.2 lounge duologic, however the ABS does not work, and there are no warning lights.

If I test the brakes and simulate an emergency stop, the wheels lock, and there is no ABS vibration in the brake pedal. Strange thing is that there are no ABS or any other warning lights, and everything else functions as intended. (apart from a slight knock when coming to a stop under 10mph - this seems to well reported everywhere!)

Just wondering what the issues could be here? It can't be the fuse, because that would knock out the power steering etc, and if it was an ABS pump failure etc, I'd at least get a warning light?!

Any suggestions or advice welcome!

Thanks !

 

[jrkitching]

and if it was an ABS pump failure etc, I'd at least get a warning light?!

Unless some unscrupulous person has messed with the warning light.

Does the ABS light come on briefly when you first turn the ignition on?

 

[AcidMonkey]

Unless some unscrupulous person has messed with the warning light.

Does the ABS light come on briefly when you first turn the ignition on?

Just had a quick check, orange ABS light comes on briefly, but then just goes away once the engine starts.

I might add the car has got nasty chinese tyres on, (Revelo branded), but I wouldn't think that would affect the ABS!

 

[jrkitching]

Just had a quick check, orange ABS light comes on briefly, but then just goes away once the engine starts.

That's normal behaviour.

I might add the car has got nasty chinese tyres on, (Revelo branded), but I wouldn't think that would affect the ABS!

Me neither - if a wheel is about to lock, then the ABS should kick in. Nasty chinese tyres may make that more likely, but shouldn't fundamentally change the way the ABS system behaves.

Failing in this silent mode is most worrying as it indicates the car's on board self diagnostic function can't be trusted. Please do keep us informed regarding the outcome.

When you tested your ABS by braking heavily, did you happen to notice if the hazard warning lights were automatically activated?

 

[AcidMonkey]

When you tested your ABS by braking heavily, did you happen to notice if the hazard warning lights were automatically activated?

Yup did notice the hazard warning light flashing rapidly - tbh I thought the brake performance was pants, and that there was no reason for the hazards to come on! I noticed the front right wheel definitely locking...

The bizarre thing is that there is no "ABS vibration" feedback to the brake pedal, when emergency braking so I'm assuming its not active. Does the fiat have this feature?

This is the wifes car, and I drive a Boxster so I could be comparing apples and oranges!

 

[jrkitching]

Yup did notice the hazard warning light flashing rapidly - tbh I thought the brake performance was pants, and that there was no reason for the hazards to come on! I noticed the front right wheel definitely locking...

All normal bar the front wheel locking up.

It's possible you might have a sticking pad that's not releasing properly in response to the ABS modulation.

Read this thread for more information.

The overall poor braking performance may be an indication of the limitation of the cheap chinese tyres. If the wheels are locking, basically it isn't going to stop any faster unless you change the tyres.

 

[AcidMonkey]

It's possible you might have a sticking pad that's not releasing properly in response to the ABS modulation.

The overall poor braking performance may be an indication of the limitation of the cheap chinese tyres. If the wheels are locking, basically it isn't going to stop any faster unless you change the tyres.

Thanks for your helpful response! You know, this actually makes a lot of sense as too what the issue is. Dear wifey bought a car, and then was too scared to drive it for 6 months whilst she was taking more driving lessons after she passed her test.

Long story short, I took the car for a drive to let the car breath and charge the battery, however there was quite a bit of brake "stick", the brakes hadn't quite seized, but the car was braking on its own if i let go of the accelerator pedal.

After heavy use of the brakes, it seemed to clear (I was thankful at the time it didn't need a trip to the garage!). Seems it'll need a trip after all!

 

[typecastboy]

Why you diss the Chinese tyres, are they really that bad we're not driving formula one cars after all.

 

[John202020]

Question, if you start the car, drive to the end of the street , brake whilst turning left , do you get vibration in the brake pedal for a brief moment?

 

[AcidMonkey]

Why you diss the Chinese tyres, are they really that bad we're not driving formula one cars after all.

Because there is a hugely noticeable difference in not only steering feel, but also very poor handling and braking performance, dangerous levels of grip in wet conditions, a massive tendancy to aquaplane and horrible tyre roar on the motorway. This is all easily noticeable on the road within the legal speed limits.

The main points being very poor braking performance in the wet. (which it is a lot in the UK!)

At the end of the day, you get what you pay for, and safety is not something anyone should skimp on.

Tyres are the only contact between your car and the road, and in an emergency situation, such as breaking at 70mph in the rain, a good tyre will save your life due to it's superior stopping distance, often being able to bring the car to a halt 10 meters before a poor quality one.

For a car in regular use, skimping on decent tyres is as stupid as not changing your brake pads or discs when they are required.

 

[AcidMonkey]

Question, if you start the car, drive to the end of the street , brake whilst turning left , do you get vibration in the brake pedal for a brief moment?

I never get the ABS pedal modulation, but I haven't emergency braked the car whilst going around a corner - there's no ESP, and the car will likely end up in a spin (and possibly into a wall ) I'm not looking to dangerously unsettle the car!

There is very very slight vibration in the pedal always when braking, similar, but much less severe in comparison to when a car has warped rotors/discs, but its probably due to the brake pad not releasing itself properly as per the above posts.

 

[UFI]

Why you diss the Chinese tyres, are they really that bad we're not driving formula one cars after all.

In my experience, yes. A former employer fitted them to a van I drove. The previous 400km fuel range was immediately reduced to 350km, and the tyres were so out of round you could feel the van moving side to side on a smooth road. I ended up torturing those tyres as I couldn't be rid of them soon enough.

10% loss of economy and added wear on all your drive/ suspension components makes them exceptionally poor value, even if you just drive to the shops.

 

[typecastboy]

I'm not convinced. I had a long chat with a tyre "expert" at a local tyre place I use. Not Kwik Fit, a proper knowledgeable place. He said their budget tyres were good and that they may just wear slightly quicker. He said he used them on his car. You can't get a better recommendation than that. If a tyre was so far out if round, then it wouldn't seal to the rim surely?

 

[Adambsmith]

Slightly off topic-apologies

I once went budget no-nameo tyres. Never ever again. Going around a busy roundabout at a sensible speed and having no steering effect at all in the wet does not make for a safe drive.

Why mess with those 4 patches of rubber that stick the car to the road?

Will always go for a premium and tested brand in future.

 

[John202020]

I never get the ABS pedal modulation, but I haven't emergency braked the car whilst going around a corner - there's no ESP, and the car will likely end up in a spin (and possibly into a wall ) I'm not looking to dangerously unsettle the car!

There is very very slight vibration in the pedal always when braking, similar, but much less severe in comparison to when a car has warped rotors/discs, but its probably due to the brake pad not releasing itself properly as per the above posts.

Sorry I think I did not explain properly, same as above at the end of the street going slowly when I turn and gently press the brake pedal I get about 4/5 gentle kicks from the brakes that I'm told is the abs self test on our 2009 car. You can't miss the feeling.
Regardless of cheap tyres there's something wrong.

 

[UFI]

If a tyre was so far out if round, then it wouldn't seal to the rim surely?

If the bead is sound, then you could have a square tyre seal correctly. Tyre construction starts at the bead, then layers are added. Each layer is an opportunity to screw up. It's not hard to see how a tyre could be out of round if care isn't taken in the layering process. I once had someone tell me how he likes X tyres because they were nice and round, and I always thought that was an odd statement until I drove on no name Chinese tyres.

The real question is why bother, if you can buy a "Goodride" for $62 or get an actual Dunlop for $3 more?

 

[typecastboy]

If only that was the difference in the price.

 

[Mikehep]

Just a thought. When tyres, chinese ones are fitted, if all that's been said is true, then when it comes to balancing them surely this would show up when spun up to speed would need loads more weights to be added???

 

[UFI]

If only that was the difference in the price.

I check online before posting, AU price for a Pop tyre was $3 cheaper. I looked at bigger sizes and the difference was zero. Even Pirelli's could be had for only about $20 more.

Personally, I only ever buy quality tyres, even my trailer runs Conti's, at $170ea. The cost is roughly equal to the fuel savings.

 

[AcidMonkey]

I'm not convinced. I had a long chat with a tyre "expert" at a local tyre place I use. Not Kwik Fit, a proper knowledgeable place. He said their budget tyres were good and that they may just wear slightly quicker. He said he used them on his car. You can't get a better recommendation than that. If a tyre was so far out if round, then it wouldn't seal to the rim surely?

Your "expert" is talking absolute nonsense.

Budget tyres tested here (among many other authoritative motoring publications) against premium brand tyres, and the results are startling with budgets taking over 40 meters longer to bring the car to a halt.

On a fiat 500 Continental/Dunlop etc tyres are £25 more per corner than the cheapest chinese non-branded tyre. Thats £100 more than the cheapest new tyres for the whole car, and they'll last for around two years with average mileage.

You'd rather put you and your family's safety at risk for the sake of saving the equivalent of £4 a month?? Complete and utter false economy.

http://www.autoexpress.co.uk/car-ne...parison-choosing-the-right-tyres-for-your-car