7.12.5 Exhaust flaps – Actuator function check
Preconditions
☑Engine is stopped and starting disabled.
☑Operating voltage is not applied.
WARNING
Exhaust flaps close rapidly.
Risk of crushing hands!
• Using a suitable tool, check exhaust flaps by pressing the actuating linkage to its limit several
times and releasing it.
WARNING
Component is hot.
Risk of burning!
• Wear protective gloves.
Checking actuator function – mechanical
Note: For installation position of exhaust flaps, refer to overview (→ Page 144).
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 144).
1. Switch on ECU.
2. Learning cycle is carried out.
Result: If the exhaust flaps don't move, contact Service.
MS150112/01E 2014-10
| Task Description | 145
TIM-ID: 0000027108 - 005
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