Bosch Climate 5000 Series Service Manual page 43

7.6.1 EEPROM parameter error diagnosis and solution (EH 00/EH 0R/EC 51)
Error Code
Malfunction decision conditions
Supposed causes
Table 21
Troubleshooting:
Power off, then restart the
unit 2 minutes later.
If error continues
Replace the outdoor
main PCB.
If error continues
Replace the indoor
main PCB.
Figure 35
EEPROM: a read-only memory whose contents can be erased and reprogrammed
using a pulsed voltage. For the location of EEPROM chip, please refer to
the below photos.
Indoor PCB
Figure 36
The two photos above are for reference only, they may not be identical to
the PCBs shipped with your equipment.
Bosch Wall Mounted Ductless Split Air Conditioner / Heat Pump IDU-ODU - BTC 769102301 A (11.2022)
EH 00/EH 0R (Indoor)
EC 51 (Outdoor)
Indoor or outdoor PCB main chip does not receive feedback from EEPROM chip.

Incorrect installation of indoor to outdoor control wire or line voltage wiring

PCB faulty
Outdoor PCB
Service Manual
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