Three problems related to brake antilock control unit/module have been reported for the 1999 Volvo S80. The most recently reported issues are listed below.
1999 S80 stalled/surged at 20,000 miles at the time. The consumer stated whenever the stalling occurred, the cruise control would go out, and at highway speeds the engine would start to run in an uneven/hesitation mode. The problem was much worse at lower speeds. The dealer installed two software updates at different times which did not fix the problem. Finally, the problem was fixed when the airflow sensor and the abs control unit was replaced.
: the contact stated while driving various speeds (15-75 mph) on normal road conditions with the cruise control engaged and after an extended ride from 45 to 90 minutes, all warning lights illuminated. The cruise control disengaged by it self and the engine hesitated. The vehicle was taken to the dealership twice, who performed a NHTSA recall #06v41000 which entailed upgrading the current software. However, the problem was not corrected either time, the lurch/stall problem continued. The dealership and the manufacturer coincided the replacement of the air flow control and the abs control unit was not covered by the vehicle's extended warranty, eventhough those replacement corrected the problem. The contact was very concerned because the recall did not solve the dangerous problem. Updated 12/28/2006 -.
: the contact stated while driving 30 mph, a brake failure warning, power steering warning, check engine warning light, abs warning light, and stability traction control failure warning messages illuminated intermittently. The vehicle was taken to a service dealer where it was determined that the abs module was worn out and sending a false signal to the warning message readout. There were no repairs made.