1999 Cadillac DeVille Owner's Manual - Page 249

yellowblue If you get the overheat warning with no sign of steam, try this for a minute or so: 1. If your air conditioner is on, turn it off. 2. Dial temperature control to the highest heat setting and open the windows, as necessary. 3. If you're in a traffic jam, shift to NEUTRAL (N); otherwise, shift to the highest gear while driving -- OVERDRIVE ( ) or THIRD (3). Cooling System When you decide it's safe to lift the hood, here's what you'll see: B If you no longer have the overheat warning, you can drive. Just to be safe, drive slower for about 10 minutes. If the warning doesn't come back on, you can drive normally. If the warning continues, pull over, stop, and park your vehicle right away. If there's still no sign of steam, idle the engine for three minutes while you're parked. If you still have the warning, turn off the engine and get everyone out of the vehicle until it cools down. Also, see "Overheated Engine Protection Operating Mode" listed previously in this section. You may decide not to lift the hood but to get service help right away. A. Coolant Surge Tank with Pressure Cap B. Electric Engine Fans 5-11