1993 Chevrolet Camaro Owner's Manual - Page 107

Voltmeter You can read battery voltage on your voltmeter. If it reads less than 1 I volts or more than 16 volts while your engine is running, and it stays there, you may have a problem with the electrical charging system. Have it checked right away. Driving with the voltmeter reading in a warning zone could drain your battery. If you idle your engine fora while, the voltmeter reading might move into the yellow zone. If the reading stays in the yellow zone while you are driving, you may have a problem with the electrical charging system. Have it checked. While the voltmeter reads in the yellow zone, your battery may not be able to power certain electrical accessories, like ABS. (If this happens, your ABS INOP light will come on, See "Anti-Lock Brake System Warning Light" in this part.) It' you must drive a short distance with the voltmeter reading in a warning zone. turn off all your accessories, including your comfort control and audio systems. Malfunction Ind-kator Lamp (Service Engine Soon Light) A computer monitors operationof your fuel, ignition and emission control systems. This light should come on when the ignition is on, but the engine is not running, as a check to show you il is working. If it does not come on at all, have it fixed right away. I f it stays on, or it comes on while you are driving, the computer is indicating that you have a problem. You should take your vehicle in for service soon.