Toyota Sienna Service Manual: Master cylinder pressure sensor check (when using sst check wire)

(a) Leave the vehicle in a stationary condition and release the brake pedal for 1 second or more, and quickly depress the brake pedal with a force of 98 N (10 kgf, 22 lbf) or more for 1 second or more.

(b) Check the ABS warning light stays on for 3 seconds.

HINT:

• At this time, the ABS warning light stays on for 3 seconds.
• While the ABS warning light stays on, continue to depress the brake pedal with a force of 98N (10 kgf) or more.
• The ABS warning light comes on for 3 seconds every time the brake pedal operation above is performed.
• If master cylinder pressure sensor check can not be completed, do not depress the brake pedal frequently. It may further reduce negative pressure and make the sensor check difficult to complete.
• If the negative pressure is insufficient, master cylinder pressure sensor check may not be completed. In this case, idle the engine to get enough negative pressure.
• If the brake pedal is depressed during engine stop, negative pressure may become insufficient and the BRL may come on. (It runs the motor and performs incorrect control.)