brake warning light

hi all,

when i start my audi a4 avant everyrthing is fine, but as soon as i drive off the brake warning light comes on

any ideas??

sometimes i might turn the ignition on and the brake warning light comes straight on before firig the engine up

Check your brake-fluid level

Regards
Jim

When the light comes on press the check button, this will show low fluid.
This is not the fault
The fault is caused buy battery voltage drop/spiking when cranking
Search the forum I posted the modification to remove the dash circuit from X relief cranking
You must also ensure battery is in good order
The mod involves installing a relay to the dash circuit.
Attachment 9881
Point No.
Assignment on the relay
Assignment on the relay plate (Part No.: 443,937,527)
Vehicle connection point
electric function

1
terminal 86
pin 4
near light switch, pin 2
terminal 75

2
terminal 85
pin 6
right A pillar earth point
earth

3
terminal 87
pin 8
yellow/blue cable in the wiring loom to the socket box of the right A pillar (T10c / pin 10)
signal cable of brake fluid switch, engine compartment side

4
terminal 30
pin 2
right socket box A pillar, plug T10c pin 10 (yellow/blue cable)
signal cable for brake fluid switch, dash insert side



Quantity
Part number
Designation

1
1H5.951.253
relay number 143

1
443,937,527
9 pin relay plate

2
000.979.114
Single wire of flat push-on contact with lug 6.3

2
000.979.135
Single wire of flat contact with lug 4.8

1
000.979.137
Single wire with connector A6.0

1
111.971.939.B
blue crimp connector; cross section 1.5 - 2.5mm2

3
111.971.940.A
red crimp connector; cross section 0.5 - 1mm2