I am suprised that there are no codes. You have an electronic throttle, which means that the pedal position sensor communicates with the throttle without a cable. Either the throttle position sensor has gone bad or the Electronic Throttle Module is kaput.

You could check the throttle body and look for a yellow or white tag. If it is white, the ETM is probably dead and needs to be repaired (see www.xemodex.com). If it is yellow (most likely after all of these years) look for a bad wire connection at the throttle body or the brake pedal.

A yellow tagged ETM does not mean it is good, it needs to be checked out with a good scanner.
--
Klausc, a Volvoholic