Bosch BMS500-AAU009-0AHXXA Service Manual page 41

Service Manual
8.3.10 High temperature protection of IPM module or compressor top
diagnosis and solution(P2)
Error Code
Malfunction decision conditions
Supposed causes
Table 25
Troubleshooting:
For 18K,24K,
Check if the Fastening screws
on the PCB and IPM radiator
are fixed tightly.
Tighten the screws and apply
Tighten the screws and apply
silicon grease.
silicon grease.
For other models,
Check if the air flow systems
of indoor and outdoor units
are obstructed?
Turn off the power supply and turn
it on 10 minutes later.
Yes
Check if the temperature
of compressor Top
Is more than 90°C？
Check if the refrigerant
system
is normal?
Replace the outdoor control PCB.
Figure 38
Bosch Thermotechnology Corp. | 02.2018
P2
If the sampling voltage is not 5V, the LED will display the failure.
No
Replace the outdoor control PCB.
eplace the outdoor control PCB.
Yes
No
Check if all the connections,especially
No
Yes
No
Yes
Repair the refrigerant
Bosch Climate 5000 AA Series Split Type Ductless Air Conditioner / Heat Pump | 41
Installation mistake
Power supply problems.
System leakage or block
PCB faulty
Yes
Clear up the air inlet and outlet or the heat
exchanger of indoor and outdoor units.
the connection of OLP (Over Load
Protector) sensor is good.
Yes
Measure the resistance
between the two ports of
the OLP. Is it zero?
Yes
system .
No Correct the connection.
No Replace the OLP.
Replace the outdoor control PCB.
Data subject to change