I-ABS (both lights) alternating 1KZ flash

[Twinsig]

Quick back story.

Rear brake excessive drag, cleaned pistons and flushed rear ckt,filled res to about full.

No more excessive drag.

Flashing initiates after 70-80 maybe 85 mph.

ABS still functions from front AND rear, no wheel lock up on gravel.

ABS ring looks good.

Sound like rear ABS pick up or cable?

What does the collective say? Thanks yall.

 

PS. I'm prepping for a 5k mile round trip to MT on 16 July.

[dirtrider]

Afternoon Twinsig

 

With the problem being speed sensitive it sounds like speed sensor (speed input) related but without a dealer computer or GS-911 failure codes it is just guessing.

 

Start by checking your rear crown bearing for looseness (grab rear wheel & twist/shake it.

 

Then look for a bent tooth on one of your wheel tone rings (look closely), then check the tone rings for wobble or being bent.

 

Then check the front speed sensor cable for rubbing on the front brake rotor (or signs of past rubbing).

 

Then check rear wheel sensor cable for being stretched tight or connector pulled partially apart.

 

Otherwise we will probably need failure code(s).

[Twinsig]

Then check rear wheel sensor cable for being stretched tight or connector pulled partially apart.

 

Roger that!

I got a bit dodgy with it changing out the drive shaft! And sort of hung up on it.

There's a local guy/shop with a 911, I'll go see him this week.

Thanks bro.

[Twinsig]

What's the test criteria for the sensor?

Fluke has 4.20 Meg ohms with no change/activity spinning the wheel.

 

[dirtrider]

Morning Twinsig

 

The best way is using a GS-911 & look at failure codes.

 

Lacking a GS-911 the next best way is to compare the rear wheel speed sensor to the front wheel speed sensor. I have the (ballpark) resistances written down in my shop but am nowhere near my shop for a couple of days.(BMW doesn't give any wheel speed sensor resistance check data)

 

As to "no change/activity spinning the wheel"-- put your meter on the mv A/C scale then give the wheel a spin.

[Twinsig]

"put your meter on the mv A/C scale then give the wheel a spin"

 

I was expecting to see something happen...irrelevant though, going to the shop for a diagnostic. Thnks.

Ill finish up here with an update for future reference.

[Twinsig]

i checked the front & rear sensors with my meter

 

front: AC voltage was around 2-3mv sometimes 4-5 just spinning the wheel with my hand of course.

 

rear: no voltage spinning by hand, certainly has more resistance cant spin as fast. So, I cranked the engine went to 1st gear at idle, the AC jumped around all over the place between 6 and 19mv

 

results are inconclusive (to me)

[dirtrider]

i checked the front & rear sensors with my meter

 

front: AC voltage was around 2-3mv sometimes 4-5 just spinning the wheel with my hand of course.

 

rear: no voltage spinning by hand, certainly has more resistance cant spin as fast. So, I cranked the engine went to 1st gear at idle, the AC jumped around all over the place between 6 and 19mv

 

results are inconclusive (to me)

 

Morning Twinsig

 

 

Yes, me too. Maybe you can ride the bike with your meter hooked up as that will give you a content wheel spin rate so you can positively compare front speed sensor output to rear speed sensor output.

[Twinsig]

Low fluid!

Thought I had that correct and it was the sensor when I wanked the rear cable.