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Steering -- Basic Knowledge -- 215 & 220 Chassis: Adjustments Mercedes-Benz Pullman W221

Manual & Power Steering 1 illustration ~1114 words

Entrance/exit aid steering column adjustment function - GF46.15-P-2001S

MODEL 215, 220

Entrance aid

Functional prerequisites

  1. Position measurement works perfectly
  2. Driver's door open (ignition/starter switch is removed) and
  3. Entrance/exit aid is switched on

Function

When the driver's door opens (ignition/starter switch is removed) the entrance/exit aid function is triggered with a message sent from the left front seat adjustment control module, with memory (M32/1) to the left front SAM control module (N10/6) . This control module actuates the tilt adjustment motor (up/down) (M20m2) via the left front fuse and relay module (K40/6) until the steering column has moved into the uppermost position. Positioning takes place at high speed until just before the end position. The last 2.5 mm are covered at low speed. Moving the steering column back to the driving position is triggered and takes place at low speed when the ignition/starter key is inserted in the ignition/starter switch when the door is closed. The steering column is moved into the driving position last stored for this key.

Exit aid

Functional prerequisites

  1. Position measurement works perfectly
  2. Ignition/starter switch is removed or
  3. Driver's door open with circuit 15R or circuit 15c ON and
  4. Entrance/exit aid is switched on

Function

(The exit aid function is identical to the entrance aid function)

The emergency running function is activated in the event of defective position recognition

Emergency running function, steering column adjustment, functionGF46.15-P-2002S
Position measurement, steering column adjustment motors, functionGF46.15-P-3000S
Driving position recognition, steering column adjustment, functionGF46.15-P-3001S
Steering column adjustment motor group, location/task/design/functionGF46.15-P-4101S
Left signal-acquisition and actuation module, location/task/design/functionGF54.21-P-4101S

Emergency running function steering column adjustment function - GF46.15-P-2002S

MODEL 215, 220

Functional prerequisites

  1. Steering column switch is operated
  2. Microswitch for steering column driving position (M20s1) signals: Steering column is outside the driving range

Function

The emergency running function ensures that the steering column can be moved into the driving position even in the event of a defect in position measurement and therefore the protective effect of the driver's airbag is not impaired when driving.

In emergency running mode the steering column can only be adjusted manually via the steering column switch for periods of approx. 2 seconds. For this the switch must be released after each actuation and then operated again.

In emergency running mode the steering column cannot be adjusted via the entrance/exit aid and memory (seat adjustment/mirror adjustment/steering column adjustment) functions.

Position measurement, steering column adjustment motors, functionGF46.15-P-3000S
Driving position recognition, steering column adjustment, functionGF46.15-P-3001S
Microswitch for driving position recognition, steering column, location/task/design/functionGF46.15-P-4102S

Position measurement, steering column adjustment motors, function - GF46.15-P-3000S

MODEL 215, 220

Function

For measuring the position of the steering column one Hall sensor is located at both the telescopic adjustment motor (in/out) (M20m1) and tilt adjustment motors (in/out) (M20m2) .

The Hall sensor signals are read in by the left front SAM control module (N10/6) , checked for plausibility and counted in the position counter for position measurement. The Hall pulses received are evaluated either positively or negatively depending on the actuation voltage of the motor.

Fault-free position measurement can only be carried out in the normalized condition.

Normalizing, steering column adjustment, functionGF46.15-P-3002S
Steering column adjustment motor group, location/task/design/functionGF46.15-P-4101S
Left signal-acquisition and actuation module, location/task/design/functionGF54.21-P-4101S

Drive position recognition steering column adjustment function - GF46.15-P-3001S

MODEL 215, 220

Functional prerequisites

  1. Circuit 15R ON or circuit 15 ON

Driving position recognition

To recognize the driving position of the steering column the switch status of the microswitch for steering column driving position (M20s1) is read in by the left front SAM control module (N10/6) and placed on the CAN bus as a message. If the steering column is not in the driving position and therefore the protective effect of the driver's airbag is no longer guaranteed in normal driving mode, the left front SAM control module (N10/6) sends a message to the instrument cluster (A1) via CAN. The following message appears in the multifunction display (A1p13) about this

"ENTRANCE POSITION - DO NOT DRIVE".

Microswitch for driving position recognition, steering column, location/task/design/functionGF46.15-P-4102S
Left signal-acquisition and actuation module, location/task/design/functionGF54.21-P-4101S

Normalizing steering column adjustment function - GF46.15-P-3002S

MODEL 215, 220

Functional prerequisites

  1. CAN must be activated, e.g. by switching on the side lights.

Function

For normalizing the associated software stops are stored in the left front SAM control module (N10/6) by approaching the mechanical stops of the steering column adjustment motor group (M20) . The switching point of the microswitch for steering column driving position (M20s1) is also stored. The switching point also serves as a reference point. If it is overshot, error compensation takes place in the position counter of the control module and any position error is corrected.

Normalizing is required during initial commissioning or after replacing an assembly.

The left front SAM control module (N10/6) has a non-volatile memory so that the set position values are retained even after the vehicle battery is disconnected

Normalizing tilt adjustment

The steering column is moved manually against the front stop by operating the steering column switch.

Normalizing fore/aft adjustment

The steering column is moved manually against the front stop by operating the steering column switch.

If the steering column is stiff or locked the left front SAM control module (N10/6) recognizes the current position as a new software stop. Emergency running mode is possible in spite of this.

Steering column adjustment motor group, location/task/design/functionGF46.15-P-4101S
Microswitch for driving position recognition, steering column, location/task/design/functionGF46.15-P-4102S
Left signal-acquisition and actuation module, location/task/design/functionGF54.21-P-4101S

Blocking steering column adjustment function - GF46.15-P-3003S

MODEL 215, 220

Function

The left front SAM control module (N10/6) constantly receives signals from the Hall sensors of the steering column adjustment motor group (M20) actuated. The signals are evaluated for position measurement . If the time intervals at which they enter the control module are too long or are missing altogether, locking is recognized and the actuation is terminated.

If the steering column is adjusted towards the top or rear stop, the control module cannot distinguish whether locking has occurred or whether only the mechanical stop has been reached and therefore carries out normalizing

Position measurement of steering column adjustment motors, functionGF46.15-P-3000S
Normalizing steering column adjustment, functionGF46.15-P-3002S
Left signal-acquisition and actuation module, location/task/design/functionGF54.21-P-4101S

Motor group steering column adjustment arrangement/purpose/design/function - GF46.15-P-4101S

MODEL 215, 220

Steering column adjustment motor group, locationGF46.15-P-4101-01S
Steering column adjustment motor group, taskTilt and fore/aft adjustment of steering column
Steering column adjustment motor group, designThe telescopic adjustment motor (in/out) (M20m1) and tilt adjustment motor (up/ down) (M20m2) are direct current motors the speed of which depends on the level of actuation voltage. They have one Hall sensor each for positioning.
Steering column adjustment motor group, functionGF46.15-P-4101-02S

Motor group steering column adjustment - GF46.15-P-4101-01S

The telescopic adjustment motor (in/out) (M20m1) and tilt adjustment motor (up/down) (M20m2) are located on the steering column.

Identifying Telescopic Adjustment Motor (In/Out) And Tilt Adjustment Motor (Up/Down). Scheme 17

Scheme 17: Identifying Telescopic Adjustment Motor (In/Out) And Tilt Adjustment Motor (Up/Down)

Motor group steering column adjustment function - GF46.15-P-4101-02S

Fore/aft adjustment

The telescopic adjustment motor (in/out) (M20m1) moves the steering column towards the driver or away from him.

It is actuated by the left front SAM control module (N10/6) via two relays in the left front fuse and relay module (K40/6) . Depending on the desired direction of rotation of the motor either jacket tube horizontal adjustment relay 1 (K40/6kD) or jacket tube horizontal adjustment relay 2 (K40/6kE) is actuated.

Vertical adjustment

The tilt adjustment motor (up/down) (M20m2) enables the adjustment of the steering column tilt. It is actuated by the left front SAM control module (N10/6) via two relays in the left front fuse and relay module (K40/6) . Depending on the desired direction of rotation of the motor either the jacket tube vertical adjustment relay 1 (K40/6kI) or jacket tube vertical adjustment relay 2 (K40/6kJ) is actuated.

When the steering column is adjusted automatically (memory function) both motors are actuated in parallel .