Throttle Body: Service and Repair

Removing And Installing/Sealing Throttle Assembly (M52TU)
- Turn off ignition.



Follow instructions for disconnecting and connecting battery, Disconnect battery negative lead from battery and lay to one side.




- Remove intake filter housing. Service and Repair
- Remove air-mass flow sensor. Service and Repair



- Pull throttle cable upwards out of retainer (1) and unhook from throttle actuator.

Installation:
Adjust throttle cable for throttle actuator,



- Release hose clamps (1).
- Detach intake hose piece from throttle assembly and idle-speed control valve.



Disconnect following plug connections:
(1) Resonance flap
(2) Idle-speed control valve



Disconnect following plug connections:
(1) Oil pressure switch
(2) Oil temperature switch



- Release screws (1) on cable duct mounting.



- Unclip fuel lines and cable of oil level sensor out of holder (1) on oil dipstick guide tube.
- Detach oil return line (2) from oil dipstick guide tube.
- Release screw (3) and remove oil dipstick guide tube.

Installation:
Replace sealing ring for oil dipstick guide tube.



- Press cable duct (1) to one side and disconnect plug connection (2) on throttle assembly.
- Release screws (3) and remove throttle assembly.




Installation:
Replace sealing ring (1) between throttle assembly and intake manifold.




Installation:
- Throttle assembly plug must be locked before connection.
- Hold receptacle housing and turn locking ring in direction of arrow until lock snaps audibly into place.
- Between arrow (1) and arrow (2) is an opening (3) through which red locking pin must be visible when plug is correctly locked.




Installation:
- For purposes of clarity, this work step is shown on a throttle assembly that has been removed.
- Align plug so that arrow (1) is flush with arrow on bush of throttle assembly.
- Push plug onto bush. Turn locking ring in direction of arrow until arrow (2) is flush with arrow on bush of throttle assembly.




NOTE:
A faulty throttle adjusts the adaptation values stored in the DME control unit. These adaptation values must be reset after the throttle assembly has been replaced.

Clearing adaptation values:
- Connect DIS Tester
- Select vehicle type
- Select "DME Motor Electronics MS42" carry out individual brief test
- Continue with bottom right arrow
- The "Fault pattern selection" window appears.
Select "Function selection" (bottom left)
- The "Function and component selection" window appears:
- Select "Service functions"
- Select "Drive"
- Select "Digital Motor Electronics"
- Select "Reset adaptations"
- Select "Test schedule" (bottom left)
- The "Test schedule" window appears.
Select "Reset adaptations"
- Continue with bottom right arrow
For subsequent procedure, follow DIS instructions. The new adaptation values are stored in the DME control unit after the engine is started for the first time.