12 72 010 Removing and installing/replacing throttle actuator (S62)
Switch off ignition.
Remove and install intake air manifold, refer to 11 61 050 REMOVING AND INSTALLING INTAKE AIR MANIFOLD (S62) .
Disconnect plug connections (1).
Unclip cables (2) from cable guides.
Disconnect plug connections (1) on left knock sensor pair.
Disconnect plug connection (1) on throttle actuator.
Unhook cable duct (2) from mounts and raise approx. 2 cm.
Installation:
Check seating of rubber grommet on ignition coil cable.
Unclip cable strip (3) from injector valves, push upwards and tie back with cable ties (e.g. to engine hood).
Unhook pull rods (1) at ball heads on servomotor side.
Release screws (2).
Lift out injection pipe (3).
Installation:
Check sealing rings on fuel injectors for damage, replace if necessary.
Coat sealing rings with anti-friction rubber coating (e.g. petroleum jelly).
Release screws (1).
Unclip plug (2).
Lift out throttle actuator (3).
If it is assured that the basic setting of the throttles has not been altered, it is sufficient to synchronize the two cylinder banks with each other as described below.
Synchronizing cylinder banks with each other:
- pull rod has been replaced
- throttle actuator has been replaced
Remove and install sealing flange for left intake air manifold. Refer to 11 61 056 REPLACING SEALING FLANGE FOR LEFT OR RIGHT INTAKE AIR MANIFOLD (S62) .
Prepare special tool kit 13 0 150:
Insert extension pin (1) into dial gauges.
Position dial gauge plates on throttle body of cylinders 2 and 3 and throttle body of cylinders 6 and 7. Mount dial gauges with inserted extension pins in dial gauge plate supports for measuring at throttle bodies 3 and 6.
If necessary, press pull rods off ball heads on servomotor side.
Turn dials on both dial gauges so that large needles point to zero.
Gently open and close each throttle bank several times to check if the large needles are always pointing to zero.
If necessary, correct dials.
Open throttles to do so.
Initial adjustment of pull rod length (center distance of ball sockets):
- Non-adjustable pull rod (cylinder bank 1-4): 131.7 +/- 0.4 mm
- Adjustable pull rod (cylinder bank 5-8): 133 +/- 0.8 mm
Further procedure for such vehicles, refer to 13 54 ... SUPPLEMENTARY WORK FOR BASIC THROTTLE SETTING (S62) .
Clip in non-adjustable pull rod (1) on throttle and servomotor sides.
Clip in adjustable pull rod (2) on throttle side and rest against ball head on servomotor side. If necessary, correct length of adjustable pull rod by turning hexagon head so that ball socket is centrally aligned to ball head.
Then clip in adjustable pull rod (2) on ball head on servomotor side.
Connect servomotor to engine wiring harness.
Activate servomotor by means of DIS Tester or MoDiC to specified value 1 %.
Servomotor shaft with twin lever would thus receive a different radial position. This would result in an incorrect measurement result and incorrect throttle setting.
When the servomotor is activated at 1 %, throttles 3 and 6 are opened to such an extent that the dial gauges indicate a change between 0.2 mm and 0.4 mm. Check whether both dial gauges indicate the same value.
If necessary, turn hexagon head (1) on adjustable pull rod slightly until both dial gauges indicate the same opening value for throttles 3 and 6.
Enter specified value of 0 % and re-enter specified value of 1 %. Check whether both dial gauges indicate the same opening value for throttles 3 and 6.
Deviation between both dial gauges must be less than 0.03 mm.
Adjusting full-load adaptation stop:
Activate servomotor until throttles are fully open and stop screw (1) rests against stop lug.
Turn stop screw to set measurement (A) of 24.2 mm +/- 0.5 mm.
Carry out measurement on all throttles on cylinder bank 5-8.
Activate servomotor and check whether measurement (A) is in tolerance range on all 4 throttles 5-8.
Throttles 1 to 4 open noticeably less. Do not correct.
Check stored fault messages.
Rectify faults.
Now clear the fault memory.