A319
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Returned To Gate; Flight Crew Rejected Takeoff
Aircraft
I was the PF (Pilot Flying) when we initiated takeoff from Runway XXR at ZZZ.  Flex power was set and prior to the 80 knot call; we had an ECAM Caution for #1 Engine Bleed Vane Failure - or words to that effect.  CA (Captain) and I recognized the ECAM and CA called 'Reject; my aircraft;' I responded 'Your aircraft'; a positive transfer of control was made; the auto brakes engaged; and the aircraft was promptly stopped per SOP.  Of note is the fact that this ECAM Caution was not inhibited; but the auto brakes did activate; so our speed must have been below 80 knots at the time of the ECAM caution; but greater than 72 knots given auto brake activation.  During the stop; CA had difficulty advancing the thrust levers out of the reverse range and briefly pushed them significantly into the forward thrust range of travel.  As the engines accelerated in forward thrust; I advised CA of the position of the thrust levers and he promptly retarded them to the forward idle position.  We made a quick assessment of the situation and CA proceeded to exit the runway at the first available forward high-speed taxiway; with me advising ATC of the situation.  While doing this; CA advised the FAs to remain seated via the PA.  As we exited the runway; CA noticed the ECAM Caution directed us to place the #1 Engine Master in the 'Off' position.  CA instructed me to do this and I promptly complied.  CA then brought the aircraft to a complete stop and assessed brake temperatures and other factors.  Correctly judging that we were in a stable and safe situation; CA checked with the FAs to ensure they and the passengers were safe and to advise them that we had experienced a low speed rejected takeoff and he would contact them to advise of the next steps.  CA and I then consulted the QRH to see if there was an ECAM Exception or Follow-Up to our ECAM Caution.  There was no further guidance in the QRH; so CA advised me to inform ATC we would be contacting Maintenance and then getting back with ATC to advise them of our intentions.  CA contacted Maintenance; who said they definitely wanted us to return to the gate; I advised Operations and Ramp Tower of our need to return to the gate and they assigned us gate X.  I subsequently coordinated with Ground our return to the gate while CA advised the FA's and passengers of the situation.  We returned to the gate without mishap; deplaned; and continued the flight on a different airplane.I have no idea why the ECAM Caution appeared.  Other than a brief excursion into forward thrust due to the mechanical difficulty of moving the thrust levers out of the reverse thrust range; this rejected takeoff followed SOP and was unremarkable.Increased training and guidance for low speed rejected takeoffs would be helpful.  Perhaps a section in the QRH with emphasis that it is the sole source for immediate guidance following a low-speed reject.
A319 First Officer reported a rejected takeoff after receiving an ECAM Caution for Number 1 Engine bleed vane failure.