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Home >> Mercedes Benz >> 2021 >> A220 Base >> Repair and Diagnosis (Single Page) >> Steering >> Steering Control Systems >> Steering - 177 Chassis >> Testing & Repair >> Remove/Install Electrical Power Steering (ES) Control Unit Motor - AR46.20-P-0701MFA
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Remove/Install Electrical Power Steering (ES) Control Unit Motor - AR46.20-P-0701MFA

Model 118, 177, 247 

Shown on model 177.0 

Fig 1: Electrical Power Steering Actuator/Motor Components Location - Model 177 (Shown On Model 177.0)
G15491934Courtesy of MERCEDES-BENZ USA
G15491935Courtesy of MERCEDES-BENZ USA
WARNING Risk of injury  . Skin or eye injuries may result when handling hot or glowing objects. Wear protective gloves, protective clothing and safety glasses, if necessary. AS00.00-Z-0002-01A
WARNING Risk of injury  . Moving parts can pinch, crush or, in extreme cases even sever extremities. No parts of the body or limbs should be within the operating area of mechanical components when moving components. AS00.00-Z-0009-01A
CAUTION Risk of injury  caused by scraping or cutting body parts on sharp vehicle parts Always wear protective gloves when working on or near sharp and non-deburred vehicle parts.
Deburr repair panels.
AS00.00-Z-0017-01A
Notice  Information on preventing damage to electronic components due to electrostatic discharge   AH54.00-P-0001-01A
  Notes on repair work on suspension components   AH00.00-P-0100-01A
REMOVINGINSTALLING Remove/install     
1 Turn front wheels to straight-ahead position and fix steering wheel at center position. SPECIAL TOOL Retainer device Fig 2
2 Switch off ignition and store transmitter key outside of transmission range (min. 2 m).    
3 Remove lower engine compartment lining. Model 118, 177, 247 with engine 260
with code M016 (Uprated engine)
Model 118, 177, 247.7 with engine 139
AR61.20-P-1105MFR
    Model 118, 177, 247 with engine 260
except code M016 (Uprated engine)
Model 118, 177, 247 with engine 282
AR61.20-P-1105MFA
    Model 118, 177, 247 with engine 608, 654 AR61.20-P-1105MFE
4 Release and disconnect electrical connections (1).    
5 Remove screws (2). INSTALLATION IMPORTANT Replace screw/bolts (2).  
    TORQUE SPECIFICATION Bolt, motor controller unit (ES) to rack-and-pinion steering *BA46.20-P-1003-01T 
6 Remove electric power steering actuator motor (A91m1). INSTALLATION IMPORTANT Replace sealing ring (3).
Ensure that the sealing ring (3) is seated correctly.
 
7 Protect rack-and-pinion steering and electric power steering actuator motor (A91m1) against soiling using lint-free rags. IMPORTANT Soiling on the inside will result in destruction of the rack-and-pinion steering or the electric power steering actuator motor (A91m1).  
INSPECT Check     
8 Check damper coupling (4) for damage. INSTALLATION IMPORTANT Check that the damper coupling (4) is correctly seated.
If damage is found,

Replace electric power steering actuator motor (A91m1).
 
9 Install in the reverse order.    
  Initial startup     
10 Slowly turn steering wheel to and fro out of center position by 2°. IMPORTANT Release torsion bar in steering gear before calibration.  
11 Calibrate torque sensor of electric power steering actuator motor (A91m1). When replacing electric power steering actuator motor (A91m1).  
REFER TO SELF-DIAGNOSTIC SYSTEMS   NOTES
Do not perform any work on the vehicle during the adjustment process.
Otherwise, the adjustment may be negatively influenced.
AD00.00-P-2000-06MFA
STEERING GEAR

Number Designation Model 118, 177, 247
BA46.20-P-1003-01T Bolt, motor controller unit (ES) to rack-and-pinion steering Nm 19
Fig 2: Identifying Retainer Device (129 589 01 21 00)
G12078799Courtesy of MERCEDES-BENZ USA