You need to adjust your brake light switch. It should be located on the brake pedal. Unplug the switch and loosen the nuts to adjust the button closer to the brake pedal.
you do not adjust the brake lights check the bulbs or check switch top of brake pedal.
Adjust the brake switch which is above the brake pedal.
To adjust the brake pedal on a Citroën Picasso, first, ensure the vehicle is parked on a level surface and the ignition is off. Locate the brake pedal adjustment mechanism, usually found under the dashboard, near the brake booster. You can adjust the pedal height by turning the adjustment nut or bolt, ensuring it aligns with the manufacturer's specifications. After making adjustments, test the brake operation to ensure proper function and comfort.
To adjust the rod on a brake booster, first, ensure the vehicle is safely secured and the brake pedal is not depressed. Locate the adjustment nut on the pushrod connected to the brake pedal; loosen it to allow for length adjustments. Adjust the rod to achieve the proper clearance between the brake pedal and the pushrod, typically around 1/16 to 1/8 inch. Finally, tighten the adjustment nut securely and check the brake pedal feel before road testing.
Most brake light switches ratchet into position and self-adjust. To reset the adjustment, press the brake pedal part way down & pull the switch out toward the pedal until it clicks several times.
tighten brake switch located on top of brake pedal under dash adjust so lamps are out and come on with light pressure on pedal.
Adjust or replace the stoplight switch at the upper end of the brake pedal under dash area
Get down on the floor board and look up at the brake pedal arm. You will see a switch that the arm hits when no pressure is applied to the brake. Twist the switch and adjust so when you barely touch the pedal the brake lights come on.
adjust the rear brake by turning the self adjuster looks like a cog wheel you'll hear it click careful not to over adjust
look at the top of the brake pedal under dashboard you can usually adjust them so the brake lights dont stay on.
That one is self explanatory it is the pedal(Gas and Brake) button it adjust it like the automatic buttons for the drivers seats.