I have had a couple of fwd GMCs and on both had a digi panel device that would give me a visual indication (leds) along with a can't miss audio alarm, when something bad is about to happen to your engine. Saved me a couple of times.

www.digipanel.com

The parameters can be set at the factory for your particular needs - and the guy who sells them is a "good guy"

Chuckd
Stillwater MN

Edited by Rusty to fix link