pbr relates to one of the motor actuators i think.
there is one behind the glove box (small black box) and
two under the drivers foot well by the clutch pedal.
iput the air con into diag mode and then flap mode and
watched to see if these motors worked ,found the one
by the clutch pedal not moving.took it apart put it back
together and it seems to have cured the fault .i now get
hot and cold again.
hope this helps...