Throttle Body: Service and Repair

Removing And Installing/Sealing Throttle Assembly (S54)

Special tools required:
- 12 1 120


NOTE:
Interrogate fault memory of DME control unit.
Turn off ignition.


Remove intake air manifold.







Press lock of air hose together and detach air hose (1) from air pipe (2).







Release nuts, remove idle-speed control valve (1) together with holder from assembly and place to one side.







Detach wiring harness (1) for fuel injector rail from holder (2).
Detach hose (5) from air pipe (4).
Detach protective cap (3) from holder (2) towards top.


NOTE: For a better overview, this work step is shown on an engine that has been removed.







Release nut and remove cable (1) from holder.







Unlock plug (1) and detach from throttle potentiometer (2).







CAUTION: The connector strip (1) may break if it is removed without special tool 12 1 120







Unlock connector strip with special tool 12 1 120 in sequence 1 to 6.

Recycling
Fuel escapes when fuel lines are detached. Catch and dispose of escaping fuel.
Observe country-specific waste-disposal regulations.







Detach retainer (1).

Recycling:
Catch and dispose of escaping fuel.







Release screw connection of fuel injector rail and air pipe on left and right.
Pull out fuel injector rail towards top.

Recycling:
Catch and dispose of escaping fuel.







Installation:
Check O-rings, replace if necessary.
When fitting, coat all O-rings with lubricant SAE 90.

Remove pulse generator for inlet camshaft.







Unclip pull rod (1) for throttle actuator on throttle side.







Release screw connection of throttle assemblies.
Remove throttle assemblies.







Installation Note: Clean sealing surfaces (1). Note correct position of adapter sleeves (2).


NOTE: For a better overview, only a removed throttle assembly is shown.







Installation:
Clean sealing surfaces on cylinder head.
Replace all O-rings (1) in cylinder head.