Exhaust Flaps - Checking Operation Of Actuators - MTU 12V4000T94 Operating Instructions Manual

7.13.2 Exhaust flaps – Checking operation of actuators
Preconditions
☑Engine is stopped and starting disabled.
☑Operating voltage is not applied.
WARNING
Actuation mechanism in the exhaust and intake area closes automatically.
Risk of crushing hands!
• To carry out the teach-in routine, keep clear of the safety zone of the actuation mechanism in
the intake and exhaust area.
• Switch off the operating voltage of the engine governor before starting the mechanical test.
• Wear protective goggles.
WARNING
Hot components/surfaces.
Risk of burns!
• Allow the engine to cool down to below 50 °C before beginning work.
• Wear suitable protective equipment/thermal gloves.
• Avoid unprotected contact with hot surfaces.
Checking operation of actuators
– mechanically
Note: For installation position of exhaust flaps,
refer to overview (→ Page 120).
1. Remove guard plates of exhaust flaps.
2. Check operability and ease of movement of
exhaust flaps and control linkage by mov-
ing the assembly at the points (arrows) and
make sure that there is no excessive play.
Result: If exhaust flap is jamming, sluggish or has
too much play, contact Service.
3. Check whether the internal spring pulls the
flap into the F-position:
• Fail-safe position for bypass flap and
EGR shutoff flap: opened.
• Fail-safe position for donor cylinder flap:
closed.
Result: If the bypass flap/EGR shutoff flap is
closed or the donor cylinder flap is opened,
contact Service.
Checking operation of actuators – electrically
Note: For installation position of exhaust flaps, refer to overview (→ Page 120).
1. Switch on ECU.
2. Teaching run is carried out.
Result: If the exhaust flaps do not move, contact Service.
122 | Task Description | MS150096/03E 2015-04