2006 X5 M54 138K with RED Brake Light---SOLVED (LF Sensor)
 

Hi any Brake guru can help?

2006 X5 M54 138K with RED Brake Light...

Not the famous Trifecta, but ONLY one RED light is on as shown.
I have INPA, but I don't know which section of INPA to open to look.
Hopefully this is not the DSC Module.

- How do you approach the RED Brake light?
- What software, what trick?
- What is the usual culprit?

Thanks...

- FRONT Brake Pads: 8mm.

- REAR Brake Pads: brand-new. Stupid me, no message on the dash but I replaced the REAR brake pads only to find out the pads were 5mm and the sensor was still OK.
Anyway, the REAR brake pads are new, also a new sensor. RED light is still on...this is why I suspect a hydraulic system problem...

- Brake fluid full at Max.

I believe the arrows in the message box ( > <) indicate a message of some kind.
Is your message system functioning.

From the pic the car is running. Was there ANY message at startup (other than seat belt)?

It looks to me like a brake pad sensor malfunction, but without the message.

Red brake means two things:

1) hand brake applied
2) low brake fluid.

(I've also seen on x-drive but only when the TC was damaged).

- No message on the dash.

- No message at startup before cranking engine.

- Brake fluid is at Max.

- I thought it was REAR Brake pads, but once I replaced them, I realized that the REAR pad = 5 mm, and sensor was still OK.

- Anyway, I now have brand-new REAR Pads and sensor...

Brake sensor has their own icon. Oddly the icon represents drum brakes


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There must be *some* message on the dash - hence the two arrows ( >...< ) - what does the Control Check say when you push the right-hand button on the cluster?

On my '05 3.0, where I am currently battling an ongoing brake pad sensor fault,

The fault indicator for brake pad sensor is:

The red brake light and a message in the display that says "Check Brake linings"

Maybe cn90 has a malfunctioning message display. I agree the arrows indicate the presence of a message.

My goof. Hi vs. Low closure
Cluster.

If you have new pads and old sensor or forgot to reset your sensor you'll get that set of symptoms.

If you want to test the system with a worn sensor, cut the wires and short them out and then reset the sensor by turning key to run position wo starting for 60 seconds.