E4 Troubleshooting - Bosch IDS 2.0 Service Manual

Service Manual

12.3.2 E4 Troubleshooting

LED display output:
Description:
Possible causes:
Table 30
Procedure:
Figure 17
1) See Section 13.4
Bosch Thermotechnology Corp. | 07.2021
E4
Temperature sensor fault (T3, T4, T5, Th, T3L, TF)
 Temperature sensors failed – shorted or open (common cause)
 Wrong wire connections of sensor
 Ambient temperature beyond our operation range
No
Is the control board
wiring correct?
Yes
Yes
Is the T4 (ambient
temperature) <-4 °F?
No
Are temp. sensors Yes
(T3/T4/T5/TH/T3L/
Tf) open or did it
short circuit?1
No
Restart system
Correct the connection
No service required
Replace sensor
Bosch IDS 2.0 | 43
Data subject to change