MTU 12V4000M*3 series Operating Instructions Manual page 211

420 – AL L1 Aux 1
Limit value 1
Cause
Input signal of Aux 1 has
exceeded/not attained limit value
1, depending on configuration.
421 – AL L2 Aux 1
Limit value 2
Cause
Input signal of Aux 1 has
exceeded/not attained limit value
2, depending on configuration.
428 – AL L1 T-Aux 1
Limit value 1
Cause
Temperature signal of Aux 1 has
exceeded / not attained limit
value 1, depending on
configuration.
434 – AL L2 P-Aux 1
Limit value 1
Cause
Coolant temperature too high.
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.
ZKP-Number: 2.0160.921
Corrective action
u Determine cause of limit value violation and rectify fault.
ZKP-Number: 2.0160.922
Corrective action
u Determine cause of limit value violation and rectify fault.
ZKP-Number: 2.0130.921
Corrective action
u Determine cause of limit value violation and rectify fault.
ZKP-Number: 2.0173.931
Corrective action
u Check coolant circuit.
ZKP-Number: 2.0110.921
Corrective action
u Determine cause of limit value violation and rectify fault.
MS15036/00E 2018-08 | Troubleshooting | 209