For 1990-2009 cars

The EBCM performs the initialization test at the beginning of each drive cycle. The initialization sequence briefly turns ON the electronic brake control relay, and cycles the solenoids and pump motor to check component operation. When an error is detected, the EBCM sets the applicable DTC. The initialization sequence may be heard and felt while it is taking place, and is considered part of normal system operation.

If a brake input is not seen (foot off the brake) by the EBCM, the initialization will occur immediately after start up. If the brake switch input is seen (foot on the brake) during start up, the initialization test will not occur until either the brake switch input is not seen (foot off the brake), or the vehicle speed reaches 8 km/h (5 mph). This interruption of initialization is used since brake pedal feedback on start up may cause an unwarranted complaint of brake pedal feedback upon start up.