Husqvarna Automower Technical Manual page 120

6. Trouble shooting
Table 11: Fault messages
Fault message
Rear loop sensor defect
Trapped
Upside down
120 Automower from
Cause
The cabling to the rear loop sensor is
defective or has come loose.
The rear loop sensor card is defective.
The Automower has become caught in
something.
Both, or one of, the rear screws on the
body has not been tightened correctly.
The magnet in the collision sensor pillar
is loose, twisted or missing.
The collision sensor card or the cabling
is defective.
The Automower has been lifted or has
turned over and the tilt sensor has
tripped.
The tilt sensor is defective.
™
Action
Check the levels for Af and Ar via Tools - Test - Loop
(shortcut 5-2-4). Switch between Af and Ar with the
help of Arrow up. When Ar is 0 and Af is higher than
70 (the mower is outside the charging plate, but
inside the loop) or when Quality is lower than 100%,
the cabling to the rear loop sensor is defective or has
come loose.
Check the levels for Af and Ar via Tools - Test - Loop
(shortcut 5-2-4). Switch between Af and Ar with the
help of Arrow up. When Ar is 0 and Af is higher than
70 (the mower is outside the charging plate, but
inside the loop) or when Quality is lower than 100%
and the cabling to the rear loop sensor is
undamaged, it is the rear loop sensor card that is
defective and must be replaced.
Free the Automower and rectify the reason for it
becoming trapped.
Lift the body from the rear section and feel whether it
is secured correctly. If not, tighten the screws.
Check the collision sensors via Tools - Test -
Sensors (shortcut 5-2-5). Check whether the
magnets on the mower, without contact, indicate a
collision.
Check the collision sensors via Tools - Test -
Sensors (shortcut 5-2-5). Check the collision sensors
and the cabling to see whether the magnet is seated
correctly and that the mower, without contact,
indicates a collision.
Correct the mower.
Check the values for Tilt X and Tilt Y via Tools - Test
- Sensors shortcut 5-2-5). When any value is higher
than 20 or when the mower indicates Upside down:
Calibrate the tilt sensor (shortcut 5-6-3). When no
changes are made the control box is defective and
must be replaced. When the fault recurs within a
month after calibration, the control box is defective
and must be replaced.