NOT the trifecta red BRAKE light question

[caposto]

This is not a trifecta question (although I do have the trifecta problem) I'm trying to understand what the red BRAKE light means. For me, in the past, it was for low brake fluid or when the brake linings wore down and 'CHECK BRAKE LININGS' message appeared.


My brake linings did wear down and as they did the red BRAKE light came on along with the 'CHECK BRAKE LININGS' message. I've replaced the brake pads and the brake pad sensor. The 'CHECK BRAKE LININGS' is now gone but the red BRAKE light persists.


To be specific, when I turn the ignition on, it starts as yellow for a second and then goes to red like its running a check and getting tripped at some point.


I suspect the brake pad sensor I installed might be bad but if so, I should also get the 'CHECK BRAKE LININGS' message I would think. My brake fluid level is almost at max and I tried manually pinning the float up and also tried disconnecting and jumping the connector but that did nothing. There are no other perceived braking issues.


I read somewhere there is also a timed or mileage type warning that can trip the light but that did not specify the E53.


Any thoughts?


I've had the trifecta for a long time but never this persistent red BRAKE light so just trying to get back to yellow only!




2002 BMW X5 (E53) 3.0i

[andrewwynn]

After replacing brake pads and sensor you need to reset the system.

I believe the process is to simply turn the key to the run position and wait a full minute without turning the key to the start position.

I have the low cluster so I don't get words just the (•) icon for brake pads.

That said I don't recall the BRAKE light coming on red or yellow when the pads wore out.

Trifecta with RED brake I've only seen once and that's when the xdrive transfer case failed.

You need to pull codes and see if you have a transfer case error. Do you have a model with xdrive?

[caposto]

iDrive. Thanks, yes, it needs to be reset and that's what makes the 'CHECK BRAKE LININGS' message go away which it has so pretty sure that's done. I will try again though for longer.


The fact that it starts yellow for a second then goes red is telling me something else it going on.

[andrewwynn]

Originally Posted by caposto

iDrive. Thanks, yes, it needs to be reset and that's what makes the 'CHECK BRAKE LININGS' message go away which it has so pretty sure that's done. I will try again though for longer.


The fact that it starts yellow for a second then goes red is telling me something else it going on.

If the check pads message doesn't come up you already reset the warning.

The other main reason the red brake comes on is from the hand brake lever.

You need to pull codes. Do you have a proper BMW scan tool? I am guessing that worn oil in the transfer case will bring up the red brake

[caposto]

Originally Posted by andrewwynn

If the check pads message doesn't come up you already reset the warning.

The other main reason the red brake comes on is from the hand brake lever.

You need to pull codes. Do you have a proper BMW scan tool? I am guessing that worn oil in the transfer case will bring up the red brake

Unfortunately I do not have a BMW scan tool. I bought INPA+cable awhile back but never got it to work on my Windows 7 machine. I'm hoping someone with the same red BRAKE issue can give me some options though. Worn transfer case oil seems unlikely to cause a BRAKE light warning but I'll keep that on the list!

I have a separate light for the parking brake.

[wpoll]

Originally Posted by andrewwynn

If the check pads message doesn't come up you already reset the warning.

The other main reason the red brake comes on is from the hand brake lever.

You need to pull codes. Do you have a proper BMW scan tool? I am guessing that worn oil in the transfer case will bring up the red brake

The car in question is a pre-facelift, so no xDrive.

And no, worn transfer case oil doesn't light up anything - just sets a code in the VTG module (54C6).

[caposto]

So I had another suspicion as to what was causing this and I just confirmed it today... As part of my ABS speed sensors issue (trifecta), my speedo does cut out. It had been out for the last few drives but today when I took a drive, it was working and the red BRAKE light was back to yellow. As I drove 3-4 miles the speedo went out again and the yellow BRAKE light turned red at the same time. Confirmed.


So, if you have the persistent red BRAKE light and the 'normal' causes (brake fluid, fluid cap, brake linnings) are fine, you could have a bad left rear ABS speed sensor or one that is going bad.


Also, change your transfer case fluid just in case!!