Warning light on instrument panel

After starting my 1999 Volvo S80, the triangular warning light on the instrument panel turns orange (indicating Warning!–not red, which would indicate Danger;stop immediately!). The owner’s manual states that when the orange triangle comes on, an explanatory message will appear in the message box, but no message appears. After driving for perhaps 10 or 15 minutes, the light sputters briefly and then goes out and stays out. Curiously, this sequence happens only in cold weather; on warm days, the light doesn’t come on at all. Two different mechanics have been unable to come up with an answer.

It might be the “possible ice on the road” warning light, it’s supposed to come on at temperatures below 36 degrees. My stepfather’s V70’s and my mom’s C70 have this feature.

Thanks very much for a quick reply. The light comes on at temperatures well above 36 degrees, probably as high as 55-60. Also, it’s a relatively new development–only in the past year.