Brake Failure Warning Light + Error codes 5DA0 & 5DA1

[crimsondelo]

R1200 GS 2010 (K25)

TL;DR: Brake Failure light appeared and motoscan presented the following error code: 5DA0 & 5DA1. Where do I start?

Hello all,
Looking for a little wisdom from you knowledgeable folk.

I was riding to work the other day. I was about 30 mins into a very wet ride and I suddenly had a warning light and the brake failure light illuminated. The brakes were working fine (though I wasn't about to test the ABS on the M25 in heavy traffic)

I pulled over (when it was safe to do so) and turned the ignition off and then back on again. The lights were no longer present, so I carried on my merry way.
20 mins later the lights appeared again. Ignition off and on again and the lights cleared.
They have subsequently not come back on again on my ride home.

I've grabbed the error codes (using motoscan) and I can see they are related to the "Wheel-Speed Sensor, Rear" and give me the error codes 5DA0 & 5DA1.
I'm struggling to find any useful documentation on these error codes beyond this:

• 5dA0 Right front wheel speed sensor; accident recognition
• 5dA1 Right front wheel speed sensor; Extrapolation

My thoughts:

1. Buy a replacement rear wheel sensor
2. Bury my head in the sand and assume it will all be fine
3. Clear the fault codes and see if they come back
4. Worry that the rear sensor was impeded by a foreign body in the final drive, drain the oil and strain it with a magnet/sieve to see if I was right

 

[DJ123]

1st step is clear the fault codes and see if they return. Best case, it was a fleeting error caused by all the water, some road debris or other thing that caused the reading error.

On the Motoscan app you can (if i remember right) test the sensors, front & rear to detect if they are working.

 

[Bem]

Not too sure why you would think of buying a rear wheel sensor when the front is indicated?
And clean out the front sensor - it might be a bit of metallic muck in there.

 

[Santa-2512]

Not too sure why you would think of buying a rear wheel sensor when the front is indicated?
And clean out the front sensor - it might be a bit of metallic muck in there.

Unlikely, the sensor sits just proud of the caliper

The rear, possibly, it sits in the Cardon drive casing, and has oil and other stuff in very close proximity

if it does have loads of crap on it, it may be worth checking for freeplay in the cardon unit

 

[crimsondelo]

Not too sure why you would think of buying a rear wheel sensor when the front is indicated?
And clean out the front sensor - it might be a bit of metallic muck in there.

Motoscan said rear sensor, however looking up the code online it said front sensor.

I made the assumption that the motoscan app was probably more accurate than my ability to search online.

Ill give the front a good clean out.

 

[crimsondelo]

Unlikely, the sensor sits just proud of the caliper

The rear, possibly, it sits in the Cardon drive casing, and has oil and other stuff in very close proximity

if it does have loads of crap on it, it may be worth checking for freeplay in the cardon unit

I really hope it's fine as this was a replacement final drive, (second hand), only done 1000 miles on it.

 

[crimsondelo]

1st step is clear the fault codes and see if they return. Best case, it was a fleeting error caused by all the water, some road debris or other thing that caused the reading error.

On the Motoscan app you can (if i remember right) test the sensors, front & rear to detect if they are working.

Thanks for this. Didn't realise you could test the sensors. Will give that a go.

 

[crimsondelo]

Update: I cleared the errors and they have not come back.
Also changed the oil in the final drive which was a lovely grey colour. I'm assuming the recent flooding and general awful weather is responsible.

The magnet on the final drive plug was clean, so that's positive.

 

[Santa-2512]

But didn't you just say you replaced the rear cardon drive as well?

if your rear cardon drive was fubarred, the reluctor ring could have had a too big a gap = error code

Glad it's cleared for now

 

[crimsondelo]

Error codes have come back, in both instances I've been riding for more than an hour in poor conditions (wet and muddy).

I reckon one of the sensors is on the way out.

Sent from my Pixel 8 Pro using Tapatalk

 

[Santa-2512]

Hmm, the rear unit is enclosed, so road conditions unlikely to effect it

Have you actually been off roading ? or just in crap weather ( which shouldn't make a difference tbh)

i'd check to see if you dont have a broken wire or damage to the wiring which may be the issue

 

[crimsondelo]

Hmm, the rear unit is enclosed, so road conditions unlikely to effect it

Have you actually been off roading ? or just in crap weather ( which shouldn't make a difference tbh)

i'd check to see if you dont have a broken wire or damage to the wiring which may be the issue

No off roading, though the state of the roads in Hampshire you may as well be.

 

[TLSgazza]

But didn't you just say you replaced the rear cardon drive as well?

if your rear cardon drive was fubarred, the reluctor ring could have had a too big a gap = error code

Glad it's cleared for now

What's this here "cardon" drive you speak of? I've never heard that term before. Just wondering.

 

[Santa-2512]

What's this here "cardon" drive you speak of? I've never heard that term before. Just wondering.

its actually the cardan shaft - which runs between gearbox and rear hub / drive

 

[botus]

its most likely the brushes in the ABS pump motor - its normal on ALL BMW cars and Bikes - they design it with the fault - fit a ford motor from a focus and it goes away forever

the same fault afflicts all VAG cars but they weren't sop clever at paying off the courts - and a class action lawsuit means they have to supply a cheap repair kit

 

[TLSgazza]

its actually the cardan shaft - which runs between gearbox and rear hub / drive

I'm still none the wiser
So your cardon drive quote was wrong then

 

[crimsondelo]

Update: I've replaced the rear wheel sensor, the previous one did have damaged to the cable so I'm hopeful this will fix it.
Reading on another forum they have also stated the following potential causes:
1. ABS pump motor (as mentioned by Botus above)
2. Air bubble in the brake line somewhere
3. Dying battery.

 

[crimsondelo]

Update: Rode to work this morning, if anything the situation is worse, before the fault would appear periodically, this morning, it popped up 3 or 4 times just riding (without touching the brake).
I tested the ABS pump yesterday using motoscan app and it kicked in with no issues; these two points taken into consideration I am now thinking either:
1. there is an issue in the final drive somewhere, though I drained the oil and checked the contents which was pretty clean and the sump plug magnet was clean, there is also no free play.
2. there is a fault with the connector under the seat or further up the wiring loom.

 

[crimsondelo]

Update: I've tested the connector and there is voltage to the pins 11.70v (not sure if this is right, but it's stable).

The brake failure light is now constant. Turn the ignition on and it cycles through the check and will illuminate (not the usual flashing). I get the same symptoms if I unplug the sensor entirely.

Someone on another forum suggested that the vehicle needs to be in motion for at least 5mins before the light will go out? Perhaps some recalibration is being done.

I also noticed that I'd somehow missed the metal washer when reinstalling the sensor, that's now been replaced with a fresh o-ring.

 

[botus]

Do you have ASC ? if the sensors are the issue ASC should be going utterly mental

individual wheels locking up and doing odd things is why ABS exists - so its logic expects random weirdness from each wheel, So when a ABS sensors IPC chip or the wires start snapping the ABS just thinks its random road conditions - But the ASC is looking for beautifully aligned readings from both or it backs off the power

well worth knowing how to kill ASC, as sometimes you can't ride the bike (till its off then everything is normal)