MTU 12V4000C*5 series, Operating Instructions Manual

Page: 114 / 305

960 – AL NOx p5 min BOI max active
Cause Corrective action
Emission-related alarm. The
charge-air pressure has reached
the minimum value defined in the
performance map. The advanced
start of injection has reached its
maximum value. 1. Check operation of the bypass flap (→ Page 195).
2. Contact Service.
961 – AL NOx p5 max BOI min active
Cause Corrective action
Emission-related alarm. This fault
is a strong indication of serious
soot contamination in the EGR
cooler (sooting). The charge-air
pressure has reached the
maximum value defined in the
performance map. The retardation
of the start of injection (BOI) has
reached its maximum value. u Contact Service.
962 – AL GPS Lambda ctrlvar max active
Cause Corrective action
This fault message indicates a
heavily sooted EGR cooler. The
lambda regulator attempts to
adjust its set value but has
reached its upper limit. The EGR
shutoff flap (M53) is fully opened.
The dispenser flap (M55) is fully
closed. 1. Check operation of the EGR shutoff flap, dispenser flap and bypass
flap (→ Page 195).
2. Contact Service.
963 – AL GPS p5 ctrlvar max active
Cause Corrective action
The required charge-air pressure
could not be reached. 1. Clean air filter (→ Contact Service).
2. Check operation of the bypass flap (→ Page 195).
3. Check exhaust turbocharger (LP) – turbine housing (→ Contact
Service).
4. Check exhaust turbocharger (HP) – turbine housing (→ Contact
Service).
5. Contact Service.
964 – AL GPS p5 ctrlvar min active
Cause Corrective action
The required charge-air pressure
could not be reached. 1. Check operation of the bypass flap (→ Page 195).
2. Contact Service.
112 | Troubleshooting | MS15041/03E 2018-08
TIM-ID: 0000065298 - 004