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It usually means that the computer has detected a fault in that subsystem. If a light is flashing you should be able to use a diagnostic code scanner to figure out what's wrong.
Newer vehicles (Starting around 1999) use the OBD2 code scanners. Older vehicles use code scanners that are specific for the vehicle manufacturer.
Code scanners may be purchased at most auto parts retailers and often borrowed or rented from some of the more cooperative auto parts retailers.
First answer by Redbeard. Last edit by Redbeard. Contributor trust: 1838 [recommend contributor]. Question popularity: 38 [recommend question]




