249
8 CO/O
2
Control
8.11.4 O
2
Trim Faults
NOTICE
Depending on the parameter settings, either O
2
trim is deactivated or a fault switching of the
burner is triggered (P 142).
Factory setting: P 142 = 0 (CO/O
2
control is inactive, burner is not switched off)
O
2
fault example:
Fig. 8-40 Display of an O
2
monitoring fault
O
2
measured value at pre-purge is too large
24%
No. CO faults -
information
Fault description
0001 O
2
fault
od O
2
measured value during pre-purge is too low (P104).
O
2
actual value at pre-purge too low.
Setpoint: > 16.0% O
2
– Check the probe.
– Perform an offset calibration
0002 O
2
fault
od O
2
measured value during pre-purge is too high (P103).
O
2
actual value at pre-purge too high
Setpoint: <24.5 vol. % O
2
Probe is too cold or the offset calibration is not performed.
– Check the probe’s internal resistor.
– Perform an offset calibration.
0003 O
2
fault od
O
2
measured value after ignition is too high (P105).
The probe dynamics cannot be detected.
Setpoint: <14.0 vol. % O
2
(factory setting)
The fault occurs after a timeout if no O
2
value is transmitted by
LSB.
– Check if Lambda Transmitter is in adjustment mode.
If yes: Finish adjustment mode.
– No value is indicated:
Check LSB.
– Is the probe hot enough?
0004 O
2
fault
ot
od
No probe dynamics - O
2
trim is deactivated (P118)
No probe dynamics can be detected.
–Correction range in CMS too small or set to ’0’
0 = Default setting. The value must be set by the customer
for each specific system.
– Set the correction range.
– Is the servomotor at the upper range limit?
Reprogram the electronic ratio control.