My 2000 Volvo S80 2.9 vehicle started surging then hesitating, back & forth, at all speeds up to 70 mph interstate speeds while cruise control was on and off. When cruise control is on, after about 5-10 miles, cruise control turns itself off & car suddenly starts decelerating. After about 1 week of this, on 6/30/06 performance reduced message appeared. On 6-24-06 engine service required message appeared for a short time. After stopping and turning motor off for about 30 minutes to read owner's manual, started motor again & message has not reappeared. When cruise turns itself off, you cannot turn cruise back on until motor is stopped & restarted, then you can turn cruise control back on for about 5-10 miles then it will go back off. Surging and hesitation continues with steady pressure on accelerator (trying to maintain constant speed) and cruise control off.

- Raleigh, NC, USA