How To Erase Diagnostic Trouble Codes

Use special tool MB991529 to ground number 1 terminal of the data link connector.

Fig 1: Using Special Tool MB991529 To Ground Number 1 Terminal Of The Data Link Connector
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Depress the brake pedal and hold it.
Turn the ignition switch to the "ON" position.
After turning the ignition switch to the "ON" position, release the brake pedal within three seconds. Repeat this process of pressing and releasing the brake pedal 10 continuous times.

Fig 2: Erasing Diagnostic Trouble Codes
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Turn the ignition switch to the "LOOK" (OFF) position.
Disconnect special tool MB991529.