Strange ABS Issue

Hi All. Hope someone can help or have at least experienced this issue. I have owned my 2016 CX-5 Akera Diesel from new and its been a great car however about 5 month after owning it I come up to an intersection and didn't notice someone in my blind spot. Hit the brakes and the front right wheel locked up and left a nice dark black skid mark on the road about 8 metres long. Not ABS light. Mentioned it to the dealer at service and there are no fault codes. Since then when on a quiet street I test the brakes to see what happens and out of around 100 hard but not full braking I have only managed to get the car to do it 6 times in total. The last time I took the car straight to the dealer without turning off the engine to attempt to diagnose the issue. Again, no fault codes or lights on the dash. Every time I tested this was on a dry clean bitumen road.

Another time I was rolling down a hill at the speed limit and was just resting my foot on the brake slightly to maintain the speed limit when all of a sudden I hear a loud shuddering noise with the brake pedal pulsing like ABS normally does but I only had light brake pressure. The vehicle speed was more or less the same. This only ever happened once.

Two other times under hard acceleration to pick up speed to catch up with traffic from a stand still I have managed to spin the front right wheel hearing the tire losing grip and engine revs pick up until I eased off the accelerator pedal. Both times it was in wet weather.

I do believe all three of my issues are linked to the ABS but the dealer informed me as there is no fault code and it didn't happen when they road tested it they deemed it as working and are not willing to do anything about it. Hope you have some suggestions on where I can go with this. I have mentioned it to the dealer multiple times but they inform me that there are no fault codes at all so there is nothing to fix. Any help will be appreciated.
 

sm1ke

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Canada
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'18 CX-9 Signature
Since you seem to be able to recreate the issue, I would suggest that you buy a cheap OBD2 Bluetooth dongle. They are less than $20 on amazon. Connect it to the car and pair it with your phone, then download a free OBD2 scan app like Torque. Recreate the issue and scan for codes when it happens.

Alternatively, you can request that one of the dealership techs hop in the car so you can recreate the issue for the tech.

I'm a little unclear on what the issue is. Are you concerned about the front right wheel locking up? Reading your post again - how does the front right tire look? Any signs of uneven wear? Based on your description, I wonder if there is a bald spot on the front right tire's tread, from the hard stop you did 5 months ago. Maybe that bald spot is contributing to the issue (if there is a bald spot).
 
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2019 CX-5 GTR
My guess. Severe or several bumps in the road (uneven surface). ABS systems sense bumps in the road (tire leaves ground momentary) under hard braking the pulsing of ABS stops working effectively and there is a skid. My recommendation don't drive on bumpy roads and do hard braking :).
 
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2014 mazda cx-5 touring FWD
Regarding the ABS behavior,I'd clean any associated electrical connectors with a non residue type electronic/electrical cleaner in a spray can.Meaning wheel speed sensor connectors as well as any at the ABS module/valve assembly next to the windshield washer fluid bottle.Maybe consider having the brake system flushed with a power bleeder just for good measure.

The wheel spin is normal in my experience.Especially on a wet street.The ABS is for BRAKING not traction.The low gear is really geared low(notice how fast it winds out when in manual mode)which means lots of torque available to spin the wheel(s).I spin them sometimes on dry road as some roads are just worn smooth.Since the front wheels are not positraction,the right front is the drive wheel and will spin first as it does the pulling and gets the power.The traction is going to vary with road surface and your tires and how much power you put to the wheels.I wouldn't worry about it.
 
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Southwest Ohio
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'19 CX-5 diesel
Hard braking with an ABS equipped vehicle will still leave skid marks but they're usually pretty light. Your describing a dark 8 meter skid from right front tire which seems to indicate it was completely locked up skidding which seems abnormal to me. I also see that occurred "5 months in" so 3 or 4 years ago? If you've gone this far with little trouble, probably not much to worry about.
 
Since you seem to be able to recreate the issue, I would suggest that you buy a cheap OBD2 Bluetooth dongle. They are less than $20 on amazon. Connect it to the car and pair it with your phone, then download a free OBD2 scan app like Torque. Recreate the issue and scan for codes when it happens.

Alternatively, you can request that one of the dealership techs hop in the car so you can recreate the issue for the tech.

I'm a little unclear on what the issue is. Are you concerned about the front right wheel locking up? Reading your post again - how does the front right tire look? Any signs of uneven wear? Based on your description, I wonder if there is a bald spot on the front right tire's tread, from the hard stop you did 5 months ago. Maybe that bald spot is contributing to the issue (if there is a bald spot).
I can't reproduce it often. It has only happened about 6 times in the last 4 1/2 years since I owned it. But good idea on the OBD2 adapter, I will get one and see what comes up.

Yes I am concerned that it may lock in an actual emergency situation and make it uncontrollable. But I am more worried that now its coming up to 5 years old I am required to get the car looked at for road worthiness. One of the things they check is brake performance and if it locks and it shouldn't then the car is defected until the issue is rectified.

The tyres look ok. Unfortunately I got a new set on Continentals which are fantastic tyres but I haven't got any noticeable flat spots. I am only braking from 40 to 50km/h. The first time I had the issue was an actual emergency stop. At that point I had only owned the car for 5 months. Its now about 4 1/2 years old.
 
My guess. Severe or several bumps in the road (uneven surface). ABS systems sense bumps in the road (tire leaves ground momentary) under hard braking the pulsing of ABS stops working effectively and there is a skid. My recommendation don't drive on bumpy roads and do hard braking :).
That would be my first guess too but the road was resurfaced about 6 months earlier and is very smooth. No bumps, pot holes, debris, anything. I have been back to same spot and hit the brakes at the same place but so far there they have worked correctly. Seems totally random.
 
Regarding the ABS behavior,I'd clean any associated electrical connectors with a non residue type electronic/electrical cleaner in a spray can.Meaning wheel speed sensor connectors as well as any at the ABS module/valve assembly next to the windshield washer fluid bottle.Maybe consider having the brake system flushed with a power bleeder just for good measure.

The wheel spin is normal in my experience.Especially on a wet street.The ABS is for BRAKING not traction.The low gear is really geared low(notice how fast it winds out when in manual mode)which means lots of torque available to spin the wheel(s).I spin them sometimes on dry road as some roads are just worn smooth.Since the front wheels are not positraction,the right front is the drive wheel and will spin first as it does the pulling and gets the power.The traction is going to vary with road surface and your tires and how much power you put to the wheels.I wouldn't worry about it.
I don't want to touch anything around that area in case the dealer wants to use that as an excuse that I tampered with it and caused the accident to occur (if involved in a crash).

I understand ABS and TC are different. But for the car to determine wheel spin it would use the ABS sensors would it not? That is why I mentioned TC. One thing I have noticed is twice when the wheel has spun up it just kept spinning until I released the accelerator pedal or got up to speed. A few other times it spun up a little but the TC light came on and the engine cut power to stop the spin.
 
Hard braking with an ABS equipped vehicle will still leave skid marks but they're usually pretty light. Your describing a dark 8 meter skid from right front tire which seems to indicate it was completely locked up skidding which seems abnormal to me. I also see that occurred "5 months in" so 3 or 4 years ago? If you've gone this far with little trouble, probably not much to worry about.
When it first happened I didn't brake hard enough that some skid marks were left. The first time only a single solid black marks was left on the road. It is a very minor issue and to be honest I had more or less ignored it however next year the car has to go through a road worthiness check and if it fails with the braking test the car is defected and not registrable until the problem is fixed. If Mazda are not going to fix it because there is no fault found then I have pretty much got a car that is scrap value.