MTU 8V4000Lx4 Operating Instructions Manual page 127

431 – SS P-Coolant before Engine
Red alarm. Engine stop.
Associated parameter 2.0168.922
Cause
Coolant pressure before engine
too low (limit value 2). Flow too
low, static pressure too low.
434 – HI T-Coolant Before Engine
Yellow alarm.
Associated parameter 2.0173.931
Cause
Coolant temperature before
engine too high (limit value 1).
Engine coolant pump failure,
flow too low, air in engine
cooling system.
435 – SS T-Coolant Before Engine
Red alarm. Engine stop.
Associated parameter 2.0173.932
Cause
Coolant temperature before
engine too high (limit value 2).
Engine coolant pump failure,
flow too low, air in engine
cooling system.
443 – HI P-Charge Mix Diff.
Yellow alarm.
Associated parameter 2.0183.931
Cause
Difference in mixture pressures
sensed on A- and B-side is too
high (limit value 1).
445 – SD P-Ambient Air
Yellow alarm.
Associated parameter 1.8004.580
Cause
Ambient air pressure sensor on
ECU defective.
Corrective action
u Check engine coolant circuit (pressure and flow).
Corrective action
u Check engine coolant circuit (pressure and flow).
Corrective action
u Check engine coolant circuit (pressure and flow).
Corrective action
1. Check throttles for varying positions and malfunction.
2. Check mixture lines for leakage.
3. Check sensors and cabling (B79.22, B79.21).
Corrective action
u Check sensor and cabling, replace as necessary. Fault is
rectified following engine restart.
MS15026/00E 2015-05 | Troubleshooting | 127