7.6.12 Inverter compressor drive error diagnosis and solution (PC 04)
Error Code
Malfunction decision conditions
Supposed causes
Table 41
Troubleshooting:
Check the wiring between main PCB
and compressor
Check the outdoor fan and the
Check the compressor resistance
Replace the outdoor main PCB
Figure 59
Bosch Wall Mounted Ductless Split Air Conditioner / Heat Pump IDU-ODU - BTC 769102301 A (11.2022)
PC 04
An abnormal inverter compressor drive is detected by a special detection circuit, including
communication signal detection, voltage detection, compressor rotation speed signal detection and so
on.
Wiring mistake
IPM malfunction
Outdoor fan assembly faulty
Compressor malfunction
Outdoor PCB faulty
No
Check the IPM
Yes
outdoor unit ventilation
Yes
values
Yes
Correct the connection or replace
Yes
the wires and connectors.
Replace the IPM board or replace
No
the main PCB
Please refer to the solution of
No
Fan Speed malfunction
No
Replace the compressor.
For certain models, outdoor PCB could not be
removed separately. In this case, the outdoor
electric control box should be replaced as a whole.
Service Manual
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