Start-Up Cycle
When the ignition is turned on, a popping sound and a slight brake pedal movement may be noticed. The ABS warning indicator lamp will also be on for up to 5 seconds after the ignition is turned on. These conditions occur as part of an ABS self-diagnosis test performed by the antilock brake system. The popping noise is the result of brief activation of the solenoids inside the integrated control unit (ICU).