MTU 12 V 4000 M23F Operating Instructions Manual page 143

419 – SD T-Coolant b.Engine
Cause
Coolant inlet temperature
sensor faulty. Short circuit or
wire break
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.
ZKP-Number: 18.004.604
Corrective action
u Check sensor and wiring (B3), replace as necessary.
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.
MS150068/01E 2014-01 | Troubleshooting | 143