Bosch IDS 2.0 - Atl Troubleshooting

Service Manual Bosch IDS 2.0 | 59
Bosch Thermotechnology Corp. | 07.2021
Data subject to change
12.3.18 AtL Troubleshooting
LED display output: AtL
Description: Ambient Temperature Limited Condition
Possible causes:
 Ambient temperature beyond operating range
 Incorrect O/B thermostat setting
 T4 sensor fault
Table 46
Procedure:
Figure 33
Restart system
Replace T4 sensor
Yes
No
Yes
No service required. Wait
for temperature to be within
range
Correct thermostat setting
No
Yes
Is the ambient
temperature
beyond operating
range? 
Is the thermostat
set to energize O/B
in heating mode?
No
Did the T4 sensor
fail? 
1) Cooling:15~125°F, Heating:-4~86°F
2) See Section 13.4