A320 Captain experienced multiple ECAM faults and warnings as the second engine was shut down at the gate and power shifted to the APU generator. First Officer complied with ECAM actions while the Captain believes a computer glitch is causing false warnings.

Narrative

At gate with APU powering aircraft at second engine shutdown (no GPU available or attached) ECAM started issuing faults and warnings. Captain felt faults were generated due to power shift. First Officer wanted to immediately start running Flight Manual and/or ECAM directed procedures. First Officer very technically orientated. In between steps he was selecting and displaying alternate FMGC modes and pages as well as reviewing system status and circuit breaker status. Captain was trying to get GPU power since the APU source change seemed to generate the issues. First Officer was moving and changing things so rapidly that system stability between steps would be impossible. Captain stopped the First Officer from additional changes and established a slower pace. Captain did not trust that the displayed faults were in fact real. We were on the ground and parked which seems a low threat environment. First Officer was rushing through procedural steps and trying to confirm/verify faults via other pages and system displays. Both crew members displayed a lack of trust in the aircraft fault and warning systems. Too often we see the sole repair step performed by maintenance is to cycle power to a system to clear a fault. That re-enforces to the crews that the aircraft is subject to system glitches and sensitive to power changes.