1995 GMC Sonoma Owner's Manual - Page 102

Normal operating range shows your engine speed during normal driving conditions. For example, when the needle points to 2, it means the engine is running at 2,000 revolutions per minute (rpm). The tachometer needle will vary all the timethat the engine is running. The red warning range tells you that your engine speed is reaching its upper limits. Don't drive very long with the tachometer in the red warning range. If you have a manual transmission, shift to a higher gear as soon as possible. If you have an automatic transmission, lift your foot off of the accelerator pedal. If you drive forvery long with the tachometer in the red danger range, engine damagewill result. NOTICE: Do not operate the engine with the tachometer in the red range, or engine damage will occur. The red danger range tells you that your engine speed is at its upper limits. You should immediately shift to a highergear, or lift your foot off of the accelerator pedal. If you drive forvery long with the tachometer in the red danger range, engine damage result. will Warning Lights and Indicators This part describesthe warning lights and gages that may be on your vehicle. The pictures will help you locate them. Warning lights and gages can signal that something is wrong before it becomes seriousenough to cause an expensive repair or replacement. Paying attention to your warning lights and gages could also save you or others from injury. Warning lights come on when there may be or is a problem with one of your vehicle's functions. As you will see in the details on the next few pages, some warninglights come on briefly when you start the engine just to let you know they're working. If you are familiarwith this section, you should not be alarmed when this happens. Gages can indicate when there may be or isa problem with one of your vehicle's functions. Often gages and warning lights work together to let you know when there's a problem with your vehicle. When one of the warning lights comes on and stays onwhen you are driving, or when one of the gages shows there may be a problem, check the section that tells you what to do about it. Please followthis manual's advice. Waiting to do repairs can be costly - and even dangerous.So please get to know your warning lights and gages. They're a big help. 2-56