ABS Brake Failure Light flashing

[gthorpe]

After bleeding my brakes I'm now getting the "Brake Failure" light flashing, alternating with the flashing red light below.

 

I everything I did and made sure the control module cable was properly installed. Saw a little brake fluid dripping from the control module overflow hose so I drew some off and the level of both are OK. Can't see any loose ABS sensors on the fron or read.

 

Also, I can hear the switch's click when pressing the front and rear brakes so that seems OK.

 

Still getting the "Brake Failure" light

 

I hope I didn't screw something up, can't see how since I took my time and followed the procedure closely.

 

Does anyone have a suggestion on what to do next ?

 

Thanks

[T__]

After bleeding my brakes I'm now getting the "Brake Failure" light flashing, alternating with the flashing red light below.

 

I everything I did and made sure the control module cable was properly installed. Saw a little brake fluid dripping from the control module overflow hose so I drew some off and the level of both are OK. Can't see any loose ABS sensors on the fron or read.

 

Also, I can hear the switch's click when pressing the front and rear brakes so that seems OK.

 

Still getting the "Brake Failure" light

 

I hope I didn't screw something up, can't see how since I took my time and followed the procedure closely.

 

Does anyone have a suggestion on what to do next ?

 

Thanks

 

 

gthorpe, does you brake light work?

 

Do you any power assist or just residual braking?

 

Can you hear an ABS pump running with just the key on no brake applied?

 

Try disconnecting the battery for a minute or so then re-connect & see if you still have a problem..

 

If you can’t find anything maybe need the dealer to pull the ABS codes for you..

 

Usually with ALTERNATLY flashing lights it means low brake fluid level in the ABS system (in the controller itself)

 

Twisty

 

[gthorpe]

Twisty,

 

Thanks for the suggestions, I checked each out:

 

1). The brake light works.

 

2). Do you any power assist or just residual braking? => I have power assist, it seems to work fine.

 

3). Can you hear an ABS pump running with just the key on no brake applied? => When I first turn the ignition on I hear what sounds like the ABS pump just momentarily (like it always did before). When Apply either front or rear brake I hear the pump.

 

4). Try disconnecting the battery for a minute or so then re-connect & see if you still have a problem.. => Did that, still have the problem.

 

I read that the 1Hz alternating lights indicate either low presure (like you say) or low voltage,

 

I read that BMW ABS requires higher voltage (12.6-12.8V) . I measured my battery and its putting out 12.3 Volts. I wonder if thats enough difference to cause a failure ?

 

[T__]

gthorpe, not low fluid pressure,, low brake fluid LEVEL in the ABS reservoir(s).. Low fluid level can cause alternating flashing lights but still allow brake assist.. Have you visually verified fluid level in the ABS reservoirs? If the fluid level is up to snuff any chance you damaged a float if you used something hard to suck any old fluid out?.

 

As for battery voltage that should be much higher than 12.2 with engine ruining at above idle (should be high 13 volt range to low 14 volt range after it runs for a while & stabilizes..

 

That pump noise you hear at key on is probably the fuel pump..

 

Twisty

 

[gthorpe]

Twisty,

 

I checked the fluid level in the ABS reservoirs and it looks fine. I use a turkey baster to suck out the old fluid when bleeding them, I was careful but its possible I could have pushed it in too far.

 

I'll look into the reservoirs and see if I can detect any damage.

 

Thanks

[Ken H.]

12.3 volts is way low. When the engine is cranking, at the same time the ABS is initializing, it will drop even lower. Time for either a charge or a new one.

[gthorpe]

I opened both reservoir caps and looked in. I can't see anything that looks like a level float, So I don't think I damaged it during bleeding. Maybe the sensor failed...

 

My battery is the original and 4 years old so I'll go ahead a replace it to see if that clears up the ploblem.

 

Thanks for your advice, I appreciate it.