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Remove/Install Trailer Recognition Control Unit - AR31.19-P-1300ME

Model 167 

With Code 550 (Trailer coupling) 

MODIFICATION NOTES

02.04.2019 Function check added. Operation steps 8 and 9  
Fig 1: Trailer Recognition Control Unit Components Location - Model 167 With Code 550 (Shown On Model 167.1)
G14790563Courtesy of MERCEDES-BENZ USA

Shown On Model 167.1 

WARNING Risk of injury  caused by fingers being jammed or pinched when removing, installing or aligning hoods, doors, trunk lid/rear-end door or sliding roof. No parts of the body or limbs should be within the operating area when the components are moving. AS00.00-Z-0011-01A
Topical note  Information on preventing damage to electronic components due to electrostatic discharge   AH54.00-P-0001-01A
  Notes on HANDS-FREE ACCESS   AH80.61-P-0001-01A
  Notes on safety-relevant components   AH00.00-Z-0019-01A
REMOVINGINSTALLING Remove/install     
1 Carry out commissioning of trailer recognition control unit (N28/1). If the trailer recognition control unit (N28/1) is replaced.  
REFER TO SELF-DIAGNOSTIC SYSTEMS     AD00.00-P-2000-06ME
2 Switch off ignition and store transmitter key outside of transmitter range (min. 2 m).    
3.1 Remove right service flap in load compartment. Model 167.1  
3.2 Remove right load compartment cover. Model 167.3/9
Model 167.9 except code M036 (Maybach version)
AR68.30-P-1185MEX
    Model 167.3 AR68.30-P-1185MEC
4 Release and disconnect electrical connectors from trailer recognition control unit (N28/1). IMPORTANT The number of electrical connectors varies depending on the given national version.  
5 Remove nuts (1).    
6 Remove trailer recognition control unit (N28/1).    
7 Install in the reverse order.    
INSPECT Check     
8 Check function of electrically unlocked trailer coupling. Model 167 with code 550 (Trailer coupling)
except code 460 (Canada version)
except code 494 (US version)
except code 496 (Mexico version)
except code 625 (Australia specification)
AR31.19-P-1451ME 
9 Perform function check of light signals on trailer socket.