MTU 12 V 4000 M23F Operating Instructions Manual page 144

440 – AL L1 P-Aux 1
Limit value 1
Cause
Pressure signal of Aux 1 has
exceeded / not attained limit
value 1, depending on
configuration.
442 – AL L2 P-Aux 1
Limit value 2
Cause
Pressure signal of Aux 1 has
exceeded / not attained limit
value 2, depending on
configuration.
444 – SD U-PDU
Injector power stage supply voltage fault
Yellow alarm; warning
Cause
Sensor defect of injector power
stage, or internal fault of engine
governor.
445 – SD P-Ambient Air
Signal error, ambient air pressure sensor
Yellow alarm; warning
Cause
Ambient air pressure sensor
faulty.
144 | Troubleshooting | MS150068/01E 2014-01
ZKP-Number: 2.0110.921
Corrective action
u Determine cause of limit value violation and rectify fault.
ZKP-Number: 2.0110.931
Corrective action
u Determine cause of limit value violation and rectify fault.
ZKP-Number: 1.8004.578
Corrective action
u Replace Engine Control Unit.
ZKP-Number: 1.8004.580
Corrective action
u Replace Engine Control Unit.