Bosch Climate 5000 Series Service Manual page 70

Service Manual
7.6.13 Low pressure protection diagnosis and solution (PC 03)
Error Code
Malfunction decision conditions
Supposed causes
Table 43
Troubleshooting:
Figure 92
7 0 |
PC 03
Outdoor pressure switch cut off the system because low pressure is lower than 0.13 MPa, the LED
displays the failure code.

Wiring mistake

Pressure protector faulty

Indoor fan motor faulty

Outdoor PCB faulty

Refrigerant leak
Check wiring between the
low pressure protector
and ODU PCB
Yes
Disconnect the low pressure
protector and measure the
resistance of it. If the
protector is okay, the
value should be 0.
Yes
Check if the outdoor ambient
temperature is lower than low
end of operation range.
No
Check if high pressure valve
core is fully open
Yes
Check if the indoor fan runs
Check if the indoor fan runs
properly in cooling mode
properly in cooling mode
Yes
Replace outdoor PCB
No
Check whether the
Check whether the
refrigerant system is ok
refrigerant system is ok
Bosch Climate 5000 Series Ducted Type (Medium & High Static) Air Conditioner / Heat Pump (11.2022)
No
Connect it well
No
Replace low pressure protector
Replace low pressure protector
Yes Stop the unit
Stop the unit
Open high pressure valve
No
core fully
please refer to the solution of [fan
please refer to the solution of [fan
speed has been out of control
speed has been out of control
No
malfunction]. Find out the cause and
malfunction]. Find out the cause and
have it solved.
have it solved.
For certain models, outdoor PCB could not be
removed separately. In this case, the outdoor
electric control box should be replaced as a whole.