C013 Is a height position error.

There is a round magnet secured with a small screw that is attached to the end of the shaft where the pulleys sit on the end of the free lift ram.

When you lift this swipes past a magnetic sensor attached near the bottom of the mast via a pair of rubber buffers fixed on a bracket - make sure there is no damage to the sensor & its wiring as they can get smacked if the truck is run in to pallets / objects while the mast is lifted up.

Also remove & check the magnet, if its cracked it wont work correctly.

For the main lift:

Early Reflex use a mechanical sensor at the top of the mast that tells the truck of the main lift is activated, later Reflex use metallic sensors.
Mechanical sensors can get damaged.
The metallic sensors need to be within 5mm of the mast beam to sense correctly.

Has any electrical work been carried out inside the reach carriage lately as sometimes the wiring connectors for this sensor can be put back in the wrong place as there are spare connectors for options in there.