Editing Built-in self-test (section)

===Automotive===
{{main|On-board diagnostics}}

Automotive tests itself to enhance safety and reliability.  For example, most vehicles with antilock brakes test them once per safety interval.  If the [[antilock brake system]] has a broken wire or other fault, the brake system reverts to operating as a normal brake system.  Most automotive engine controllers incorporate a "limp mode" for each sensor, so that the engine will continue to operate if the sensor or its wiring fails.  Another, more trivial example of a limp mode is that some cars test door switches, and automatically turn lights on using seat-belt occupancy sensors if the door switches fail.