Switch Sequence

When a normal brake apply is made, the following sequence of events should take place:

1. As soon as the pedal is depressed, the brake light switch should close, providing a 12 volt signal to EBCM pin 29.
2. As the booster piston continues to move, switch S2A opens, forcing EBCM pin 28 to 2.5 volts.
3. As the brake is applied further, the control pressure switch (S1) opens, holding EBCM pin 13 at 5 volts.
4. As full pedal travel is reached, switch S2B opens forcing EBCM pin 28 to 5 volts.