There is a definition of good order in the index.
Good Order (a Personnel unit or vehicular inherent crew which is neither broken, berserk, captured, stunned, shocked, or held in Melee; or a SW which is fully manned by a Good Order Personnel unit, and is not malfunctioned, or restricted by an Ammunition Shortage):
A.7
The vehicle is never in good order, it is the crew which is. The crew cannot be berserk or held in melee as neither apply to armoured vehicular crews. All other cases coukd apply.
Merely having a malfunctioned weapon does not affect too order status.