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.
The Auto Field-Maintenance Unit can be used to repair almost any module installed on a ship. Exceptions include a ship's Power Plant, its hull, and the AFMU itself, but the latter limitation can be circumvented by installing at least two AFMUs on the same ship so that they can be used to repair each other. An AFMU can also repair damage to a Ship Canopy as long as it has not been breached.
To use an AFMU to repair a damaged module, enter the ship module list in the right-side panel of the HUD, scroll to the module, and select the "Repair" option. Only modules at less than 100% health are considered damaged and will display the "Repair" option. Once the AFMU is activated, the module chosen for repairs is automatically deactivated if it has not been already through use of the "Disable" option. Be warned that repairing Life Support will also deactivate it and switch the ship to emergency oxygen reserves, so the reserve timer should be monitored carefully during the repair process. After repairs are completed, modules must be reactivated manually by selecting the "Enable" option.
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. For example, repairing Thrusters mid-combat will leave a ship immobilized. However, it can be of great use to explorers who find themselves taking heat damage whilst Fuel Scooping, and can repair minor damage between combat engagements, such as heat damage caused by the use of Shield Cell Banks or rapidly firing Railguns and similar weapons.
AFMUs can be used to reduce repair expenses because the cost of replenishing AFMU repair material at a port is fixed at 100 CR per 100 units of material, while the cost of paying for repairs at a port can vary significantly depending on the purchase price of the module being repaired. As such, it is recommended to use AFMUs to repair any expensive modules, especially those that cost millions of credits, and use the repair service at ports to cover cheap modules.
In addition to replenishing AFMU repair material at ports, refills can also be Synthesised.
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.