Bosch 19 SEER Series Operation Manual page 33

Installation & Operation Manual
Error Code Description
L0-L9 IPM module protection
Table 25
When error codes L0-L9 appears occasionally, no action is necessary. The
system will restart automatically after 6 minutes.
L0-L9 ( IPM module protection)
Diagnosis
Check whether the compressor
wiring is normal
Yes
Check whether compressor
insulation resistance is greater
than 100KΩ
Yes
Check whether the resistance of
compressor U/V/W are normal
Yes
Check whether there is the
same fault
Yes
Replace the board and
check whether there is the
same fault.
Yes
Replace the compressor and
Yes
check whether there is the
same faultt
Figure 46
BTC 761701105 A | 03.2019
Handling
No
Reseat the wiring according
to wiring diagram
No
Replace the compressor
No
Replace the compressor
No
Keep running
No
Keep running
No
Keep running
Bosch Inverter Ducted Packaged Heat Pump | 33
Error Code Description
AtL Ambient Temperature Limited
Table 26
When the ambient temperature returns to within the operating
range, the system will recover automatically.
AtL (Ambient Temperature Limited)
Diagnosis
Check whether the ambient
temperature is beyond the range
cooling: 23°F-125°F
heating: -4°F-86°F
No
Check whether sensor T4 is
seated and normal (T4 for
Heat Pump only)
Yes
Unplug the sensor, Check
whether the resistance of T4
is in the range of Table 27
Yes
No action is necessary.
Try to restart the system.
Figure 47
Handling
Yes
Normal
No
Reseat the sensor according
to wiring diagram
No Replace the fault T3/T4
sensor
Data subject to change