1. Be aware that many of the warning and indicator lamps found on today's vehicles are triggered by a PCM or BCM. Often, they are part of the multiplexed system. With this in mind, always refer to the testing methods recommended by the manufacturer before testing these systems. Why must you follow methods recommended by the manufacturer?

1. Using conventional testing methods on a computerized system won't destroy any part or all of the system.
2. Using conventional testing methods on a computerized system may destroy part or all of the system.
3. Using conventional testing methods on a computerized system will enhance any part or all of the system.
4. All these answers are correct.