When the AFM is powered other modules can be set to repair by toggling their state in the module list. Modules will cycle from On to Off and finally to Repair. The AFM will slowly repair module that are set to repair but will consume resources to do so as indicated in the module list. The AFM can be resupplied at starports and outposts from the munitions interface.
— In-Game Description
The Auto Field-Maintenance Unit (AFMU) is a module that can be used to repair other modules. The AFMU draws from a special pool of repair "ammunition" as it repairs modules, and modules must be turned off to be repaired. This means that an AFMU can repair any module excluding itself and the ship's Power Plant, as the AFMU must be powered in order to function. Modules must be manually repowered after repairs are completed.
Given its very slow rate of repair and the fact the module to be repaired must be powered down, the AFMU is generally considered to be ineffective or even dangerous to use for in-combat attrition; repairing your thrusters mid-combat would leave you immobilized, for instance. However, it can be of great use to Explorers who find themselves taking heat damage whilst Fuel Scooping, to repair minor damage between engagements, such as heat damage from the use of Shield Cell Banks or rapidly firing Railguns and similar weapons.
Because the cost to repair a module at a Station, Starport, or Outpost is based on its purchase price, it is usually more cost effective to repair expensive modules with an AFMU than it is to repair cheaper modules, as the AFMU ammunition will cost more to replenish than the repair would cost for small, inexpensive modules. An example of this is that using an AFMU to repair a Multi-Million Credit module (High Rating Grade A Thrusters, for instance) will generally cost less than repairing it in dock, while it will cost more to repair a several thousand credit module with an AFMU compared to repairing it at a port.
NOTE: The AFMU module cannot repair the ship's power plant, itself, or the hull, but equipping more than one AFMU module will allow them to repair each other. The AFMU also cannot repair a breached Ship Canopy, but it can repair regular canopy damage.
To use, go to your module list, and the repairable modules will now have a third state - Enabled (Solid square), Repair (Slash through empty square), and Disabled (Empty Square)
Modules will be offline while in the repair state, and must be manually repowered. This means that care should be taken when repairing Life Support, as repairing it will switch you over to the Emergency Life Support Timer until you manually repower Life Support.
When replenishing by Synthesis, higher tiers of ammo provide faster repair rate.
The following modification can be applied to this module by Engineers to enhance its abilities:
- It is possible to equip two of these modules and have them repair each other or to increase the repair speed of another module.
- Due to the targeted module needing to be offline whilst being repaired, the AFMU cannot repair itself.
- Prior to Version 1.1 the AFMU was unable to repair thrusters.
- A ship power plant cannot be repaired by an AFMU, as the power plant cannot be toggled offline.
- An unbreached cockpit canopy can be repaired despite being unable to toggle it offline. A fully broken canopy cannot be repaired, though.
- Care should be taken when repairing life support, as repaired units are offline whilst under repair and remain offline afterward, needing to be manually re-enabled.
- Trying to repair thrusters or FSD while at supercruise will cause the ship to drop to normal space and take damage.