Electrical system

Chapter overview

• Technical data
  1
• 1 Safety information
  1
• 1.1 Application notes and safety information for LED headlights
  1
• 1.2 Safety measures when working on vehicles with start/stop system
  1
• 2 Repair instructions
  3
• 2.1 Rules for cleanliness
  3
• 2.2 General information
  3
• 2.3 Contact corrosion
  3
• 2.4 ESD workplace
  3
• 2.5 Routing and attachment of lines
  4
• 3 Battery
  5
• 3.1 Battery - general notes
  5
• 3.2 Types of battery
  5
• Starter, current supply, CCS
  6
• 1 Battery
  6
• 1.1 Assembly overview – battery
  6
• 1.2 Removing and installing battery
  8
• 1.3 Disconnecting and connecting battery
  11
• 1.4 Removing and installing battery tray
  13
• 1.5 Checking battery
  14
• 1.6 Charging battery
  14
• 1.7 Removing and installing earth wire with battery monitor control unit J367
  15
• 1.8 Adapting battery monitor control unit J367
  16
• 2 Alternator
  17
• 2.1 Assembly overview - alternator
  17
• 2.2 Removing and installing alternator
  18
• 2.3 Checking alternator
  23
• 2.4 Removing and installing poly V-belt pulley
  23
• 2.5 Removing and installing voltage regulator
  29
• 3 Starter motor
  32
• 3.1 Assembly overview – starter
  32
• 3.2 Removing and installing starter
  35
• 4 Cruise control system (CCS)
  45
• 5 Start/stop system
  46
• 5.1 General description - start/stop system
  46
• 5.2 Overview of fitting locations - start/stop system
  46
• Gauges, instruments
  47
• 1 Dash panel insert
  47
• 1.1 Assembly overview - dash panel insert
  47
• 1.2 Assembly overview - head-up display
  48
• 1.3 Removing and installing dash panel insert KX2
  49
• 1.4 Removing and installing control unit for head-up display
  53
• 2 Horn
  55
• 2.1 Assembly overview - horn
  55
• 2.2 Removing and installing treble horn H2 and bass horn H7
  55
• Windscreen wash/wipe system
  58
• 1 Windscreen wiper system
  58
• 1.1 Assembly overview - windscreen wiper system
  58
• 1.2 Moving wipers to service position
  61
• 1.3 Removing and installing wiper blade
  61
• 1.4 Removing and installing wiper arms
  62
• 1.5 Adjusting wiper arms
  64
• 1.6 Removing and installing wiper motor V
  65
• 1.7 Renewing wiper motor
  67
• 1.8 Deactivating APP function of wiper motor
  69
• 1.9 Removing and installing rain and light sensor
  70
• 1.10 Repairing rain and light sensor
  73
• 2 Windscreen washer system
  77
• 2.1 Assembly overview - windscreen washer system
  77
• 2.2 Removing and installing washer fluid reservoir
  80
• 2.3 Removing and installing windscreen washer fluid level sender
  83
• 2.4 Removing and installing windscreen washer pump
  84
• 2.5 Removing and installing spray jets
  86
• 2.6 Adjusting spray jets
  87
• 3 Rear window wiper system
  88
• 3.1 Assembly overview - rear window wiper system
  88
• 3.2 Removing and installing wiper blade
  88
• 3.3 Removing and installing wiper arm
  89
• 3.4 Adjusting wiper arm
  90
• 3.5 Removing and installing rear window wiper motor V12
  91
• 4 Rear window washer system
  93
• 4.1 Assembly overview - rear window washer system
  93
• 4.2 Removing and installing washer fluid reservoir
  95
• 4.3 Removing and installing rear window washer pump
  96
• 4.4 Removing and installing spray jet
  96
• 4.5 Adjusting spray jet
  96
• 5 Washer fluid lines
  97
• 5.1 Repairing washer fluid lines
  97
• Lights, bulbs, switches - exterior
  98
• 1 Headlights
  98
• 1.1 Assembly overview – headlight
  98
• 1.2 Removing and installing headlight
  103
• 1.3 Adjusting headlights
  103
• 1.4 Removing and installing front turn signal bulb M5/M7
  104
• 1.5 Installing repair kit for headlight housing
  105
• 1.6 Removing and installing headlight range control motor V48/V49
  106
• 1.8 Removing and installing LED module for daytime running light L377/L378
  115
• 1.9 Removing and installing output module 1 for LED headlight A27/A31
  117
• 2 Lights in exterior mirror
  122
• 2.1 Assembly overview - lights in exterior mirror
  122
• 2.2 Removing and installing turn signal
  123
• 2.3 Removing and installing entry light in exterior mirror
  126
• 3 Tail lights
  127
• 3.1 Assembly overview - tail light cluster in body
  127
• 3.2 Assembly overview - tail lights in rear lid
  127
• 3.3 Removing and installing tail light in rear lid
  128
• 3.4 Removing and installing tail light cluster
  130
• 3.5 Removing and installing turn signal bulb
  131
• 4 High-level brake light
  133
• 4.1 Assembly overview – high-level brake light
  133
• 4.2 Removing and installing high-level brake light
  133
• 5 Number plate light
  136
• 5.1 Assembly overview – number plate lights
  136
• 5.2 Removing and installing number plate light X4/X5
  136
• 6 Entry and start authorisation system
  138
• 6.1 Overview of fitting locations - entry and start authorisation system
  138
• 6.2 Overview of fitting locations - keyless entry system
  141
• 6.3 Removing and installing interface for entry and start system J965
  145
• 6.4 Removing and installing door exterior handle contact sensor G415/G416
  148
• 6.5 Removing and installing interior aerial 1 for entry and start system R138
  148
• 6.6 Removing and installing interior aerial 2 for entry and start system R139
  149
• 6.7 Removing and installing driver side aerial for entry and start system R134
  150
• 6.9 Removing and installing rear bumper aerial for entry and start system R136
  150
• 6.11 Removing and installing rear lid power opening control unit J938
  152
• 6.12 Removing and installing rear lid power opening sender G750/G760
  152
• 7 Steering column switch module
  154
• 7.1 Assembly overview - steering column switch module
  154
• 7.2 Removing and installing lock cylinder
  156
• 7.3 Removing and installing ignition key withdrawal lock solenoid N376
  158
• 7.4 Removing and installing ignition/starter switch
  159
• 7.5 Removing and installing steering column switch module
  160
• 7.6 Removing and installing steering column combination switch
  163
• 7.7 Removing and installing immobiliser reader coil D2
  165
• 7.8 Removing and installing base for steering column combination switch
  166
• 7.9 Removing and installing steering lock housing
  166
• 8 Automatic headlight range control
  169
• 8.1 Assembly overview - automatic headlight range control
  169
• 8.2 Removing and installing cornering light and headlight range control unit J745
  170
• 9 Towing bracket
  173
• 9.1 Assembly overview - towing bracket socket
  173
• 9.2 Removing and installing trailer socket U10
  173
• 9.3 Removing and installing trailer detector control unit J345
  174
• Lights, bulbs, switches - interior
  176
• 1 Lights
  176
• 1.1 Overview of fitting locations - lights in dash panel
  176
• 1.2 Overview of fitting locations - lights in front doors
  177
• 1.3 Overview of fitting locations - lights in rear doors
  178
• 1.4 Overview of fitting locations - lights in centre console
  179
• 1.5 Overview of fitting locations - lights in luggage compartment
  180
• 1.6 Overview of fitting locations - lights in roof trim
  181
• 1.7 Removing and installing glove compartment light W6
  183
• 1.8 Removing and installing front footwell light K268/K269
  184
• 1.9 Removing and installing Central locking SAFELOCK function warning lamp K133
  186
• 1.10 Removing and installing reflectors in door
  187
• 1.11 Removing and installing entry light W92/W93
  188
• 1.13 Removing and installing luggage compartment light W3
  189
• 1.14 Removing and installing electric torch R280
  190
• 1.15 Removing and installing surround lighting 1 in rear lid W61
  191
• 1.16 Removing and installing illuminated vanity mirror W20/W14
  191
• 1.17 Removing and installing bulb for front interior light W1
  193
• 1.18 Removing and installing bulb for rear interior light W43
  194
• 2 Controls
  196
• 2.1 Overview of fitting locations - controls in dash panel
  196
• 2.2 Overview of fitting locations - controls in front doors
  197
• 2.3 Overview of fitting locations - controls in rear doors
  198
• 2.4 Overview of fitting locations - controls in centre console
  199
• 2.5 Overview of fitting locations - controls in luggage compartment
  200
• 2.6 Overview of fitting locations - controls in roof trim
  201
• 2.7 Removing and installing rotary light switch EX1
  204
• 2.8 Removing and installing switch for head-up display E736
  204
• 2.9 Removing and installing switch module 1 in centre console EX23
  205
• 2.10 Removing and installing switch module 2 in centre console EX30
  206
• 2.11 Removing and installing operating unit for driving mode selection E881
  208
• 2.12 Removing and installing hazard warning light switch EX3
  209
• 2.13 Removing and installing glove compartment light switch E26
  210
• 2.14 Removing and installing exterior mirror adjuster EX11
  211
• 2.15 Removing and installing operating unit for window regulator in driver door E512
  212
• 2.16 Removing and installing front passenger side window regulator button E716
  213
• 2.18 Removing and installing rear lid remote release button E233
  214
• 2.19 Removing and installing rear window regulator button E711/E713
  215
• 2.21 Removing and installing the starter button E378
  216
• 2.22 Removing and installing rear lid warning buzzer H32
  217
• 2.23 Removing and installing rear lid contact switch
  217
• 2.24 Removing and installing rear lid closure button E574
  218
• 2.25 Removing and installing electric hinged tow coupling attachment button E474
  219
• 2.26 Removing and installing vanity mirror contact switch F147/F148
  220
• 2.27 Removing and installing sunroof button E325
  220
• 2.28 Removing and installing front interior light/reading light
  221
• 2.29 Removing and installing rear interior light/reading light
  222
• 2.30 Removing and installing front reading light button E633/E634
  226
• 3 Anti-theft alarm
  227
• 3.1 Assembly overview - interior monitor
  227
• 3.2 Removing and installing alarm horn H12
  227
• 3.3 Removing and installing anti-theft alarm sensor G578
  229
• 4 Cigarette lighter, socket
  232
• 4.1 Assembly overview - DC/AC converter with socket, 12 V-230 V
  232
• 4.2 Removing and installing cigarette lighter U1
  233
• 4.3 Removing and installing socket illumination bulb L42
  233
• 4.4 Removing and installing rear cigarette lighter illumination bulb L32
  233
• 4.5 Removing and installing 12 V socket 3 U19
  233
• 4.6 Removing and installing DC/AC converter with socket, 12 V-230 V U13
  233
• Wiring
  235
• 1 Relay carriers, fuse holders, electronics boxes
  235
• 1.1 Overview of fitting locations - relay carriers, fuse holders, E-boxes
  235
• 1.2 Removing and installing electronics box (E-box)
  238
• 1.3 Removing and installing relay and fuse holder in electronics box
  239
• 1.4 Removing and installing relay and fuse holder behind dash panel on driver side
  242
• 2 Select Control units
  245
• 2.1 Overview of fitting locations - control units
  245
• 2.2 Assembly overview - onboard supply control unit
  247
• 2.3 Assembly overview - data bus diagnostic interface
  249
• 2.4 Removing and installing onboard supply control unit J519
  251
• 2.5 Removing and installing data bus diagnostic interface J533
  254
• 2.6 Removing and installing bracket for onboard supply control unit J519
  255
• 2.7 Removing and installing rear lid control unit J605
  258
• 3 Connectors
  260
• 3.1 Repairing electrical wiring harnesses and plug-in connections
  260
• 4 Releasing and dismantling connector housings
  261
• 5 Repairing aerial wires
  262
• 6 Fibre optic cables
  263
• 7 Vehicle diagnosis, testing and information systems
  264