ECU MERCEDES-BENZ EQC SUV 2021 Service Manual

The component parts in
theve hicle's high-
vo ltage on-board elect rical sy stem may be
damaged in an accident, although the dam‐
age is not visible. #
Never car ryout changes on the high-
vo ltage on-board elect rical sy stem. #
Neverto uch co mponent parts in the
high-voltage on-board electrical sy stem. #
After an accident, do not touch any
high-voltage co mponents. #
After an accident, ha vetheve hicle
transpor tedaw ay. #
Have the high-voltage on-board electri‐
cal sy stem checked at a qualified spe‐
cialist workshop. Re
quirements:
Only disconnect the drive sy stem manually in
th efo llowing situations:
R The 6 restra int sy stem warning lamp
lights up in the instrument clus ter,e.g. af ter
an accident. R
The vehicle is badly damaged, e.g. af ter an
accident, and there stra int sy stem compo‐
nents ha venot been trig gered.
Operating the high-voltage disconnect
device
Only disconnect the drive sy stem manually in
th e abo ve-mentioned situations. #
Switch the ignition off. #
Shift the transmission toposition j. #
Apply the electric parking brake. #
Secure theve hicle against rolling away. #
Open the bonn et. #
Press release tab1 inthe direction of the
ar row and pull it out. #
Pull high-voltage disconnect device 2inthe
direction of the ar row until it en gage s.
The drive sy stem is disconnected.
All workon the drive sy stem (including af ter dis‐
connecting manually) may only be car ried out by
a qu alified specialist workshop. 14 8
Driving and pa rking

Calling up
the energy flow displ ay Multimedia sy
stem:
4 © 5
EQ #
Select Energy flow.
The visualisation of the energy flow inthe
ve hicle is displa yed.
In addition tothe energy flow ,th e cur rent charge
le ve l of the high-voltage battery is also dis‐
pla yed. Fu
nctions of the energy flow displ ay 1
Char geleve l of the high-voltage battery
2 Elect ric mo tors (drive sy stem)
3 Energy flow
4 High-voltage battery
The active components of the drive sy stem are
highlighted in the energy flow displa y.The
energy flow between the individual components
is shown in colour.
The energy flow is shown in dif fere nt colou rs
depending on the operating status:
R white: strong accele ration (boo steffect) R
copper: driving at cons tant speed or wi th
moderate accele ration
R blue: recuperation (cha rging the high-voltage
battery) or overru n mode Re
generative brake sy stem Fu
nction of there ge nerative brake sy stem
Depending on the selected recuperation le vel,
th e electric mo tor is operated as an alternator
when in overrun mode and during braking in
order tocharge the high-voltage battery while
driving. As soon as youre lease the accelerator
pedal when theve hicle is in motion, recupera‐
tion in overrun mode is initiated.
The higher there cuperation, the more sharply
th eve hicle is braked when coasting and the
more electrical energy is fed into the high-volt‐
age batter y.
The rege nerati vebrake sy stem has thefo llowing
ch aracteristics:
R suppo rts braking with electronically contro l‐
led brake forc e boosting Driving and parking
14 9

R
con verts th e kinetic energy of theve hicle
into electric energy
% Ifyo u brake hard, the mechanical brake is
also used. This means that the maximum
re cuperati veenergy cann otbe reco vered.
The more you drive and brake in an anticipa‐
to ry manner, the more ef ficiently there cu‐
perati veenergy can be used.
Sy stem limits
The braking ef fect of the electric mo tor during
re cuperation in overru n mode may be reduced or
may not be available at all in thefo llowing situa‐
tions:
R when the high-voltage battery charge level
inc reases
R ifth e high-voltage battery is not yet at a nor‐
mal operating temp erature
R when driving at speeds close tozero
R in transmission position i
R during and af ter ESP ®
inter venes In
these cases, the desired deceleration is set by
th e brake control sy stem. Also brake with the
service brake if necessar y.
Manually setting recuperative deceleration
%
Yo u can use thesteering wheel gearshift paddles
to manually adju st the intensity of recuperation
in ove rrun mode. %
When theve hicle is star ted again or trans‐
mission position his engaged again, the
st andard setting is automatically set. The
following recuperation le vels are available:
R hà Inte lligent and anticipatory recuper‐
ation wi thECO Assi st (/ page 155)
R hq Norecuperation: theve hicle coasts,
ro lls freely
R h Normal recuperation (s tandard setting)
R h± Increased recuperation: increased
decele ration in overrun mode
R h±± Maximum recuperation: maximum
decele ration in overrun mode #
Toincrease recuperation: briefly pull gear‐
shift paddle 1. #
Toreduce recuperation: briefly pull gear‐
shift paddle 2. #
Select hÃ: pull and hold gearshift pad‐
dle 1or2. 15 0
Driving and pa rking

must be located in
the mar ked space 2on
th e symbol 3during the entire journe y. #
Have theke y1 checked at a qualified spe‐
cialist workshop.
If th eve hicle does not star t: #
Place theke y1 inthe mar ked space 2
and lea veitth ere. #
Depress the brake pedal and start theve hi‐
cle using thest art/ stop button.
% You can also swit chon the po wer supp lyor
th e ignition with thest art/ stop button.
Obser veany information rega rding display mes‐
sages that can be displa yed on the multifunction
displa y. Ru
nning-in no tes R
in cer tain driving and driving saf ety sy stems,
th e sensors adjust automatically while a cer‐
tai n di stance is being driven af terth eve hicle
has been delivered or af terre pairs. Full sys‐
te m ef fectiveness is not reached until the
end of this teach-in process. R
brakepads, brake discs and tyres that are
either new or ha vebeen replaced only ach‐
ie ve optimum braking ef fect and grip af ter
se veral hundred kilom etre s of driving. Com‐
pensate forth ere duced braking ef fect by
applying greaterfo rc eto the brake pedal. Note
s on driving &
WARNING Risk of accident due to
objects in the driver's foot we ll
Objects in the driver's foot we ll may impede
pedal tra vel or block a depressed pedal.
This jeopardises the operating and road
saf ety of theve hicle. #
Stow all objects in theve hicle securely
so that they cannot getinto the driver's
fo ot we ll. #
Alw aysfit th efloor mats securely and
as prescribed in order toensure that
th ere is alw ays suf ficient room forthe
pedals. #
Do not use loose floor mats and do not
place floor mats on top of one ano ther. &
WARNING Risk of accident due toincor‐
re ct foot we ar
Incor rect foot we ar includes, forex ample:
R shoes with plat form soles
R shoes with high heels
R slippers
There is a risk of an accident. #
Alw ayswe ar suitable foot we ar so that
yo u can operate the pedals safel y. &
WARNING Risk of accident if the ignition
is switched off while driving
If yo u swit choff the ignition while driving,
saf ety functions are restricted or no longer
av ailable.
This may af fect the po werst eering sy stem
and the brake forc e boosting, forex ample. Driving and parking
15 3

ECO Assi
stanal yses data forth eve hicle's expec‐
te dro ute. This allo wsthe sy stem tooptimally
adjust the driving style fo rth ero ute ahead, use
minimal energy and recuperate.
ECO Assi stis displa yed on theAssistance
menu(/ page 250). 1
Event ahead, e.g. roundabout
2 Distance displ ayforth eev ent ahead
3 "Foot off the accelerator" prom pt Displ
ayable pr evious events 1
The following events 1can be de tected and
displ ayed forth ero ute section ahead:
R Vehicle in front
R Speed limit
R Downhill and uphill gradients
R Junctions and roundabouts
R Bends
The segments of dis tance displ ay2 show the
dis tance totheeve nt ahead as follo ws:
R Afew segments light up: theeve nt ahead is
nea r. R
Many segments light up: theeve nt ahead is
fur ther aw ay.
If ECO Assist is active, "Foot off the accelerator"
symbol 3will appear on theAssistance menu
on the multifunction displa y,on the head-up dis‐
play and next tothe transmission position dis‐
pla y.
When theve hicle nears an event, ECO Assi stwill
calculate the optimal speed for minimal energy
consum ption based on the dis tance and speed.
"Foot off the accelerator" recommendation 3
will appear on the multifunction displa y.
If yo uta ke your foot off the accelerator pedal in
good time, there maining segments on the dis‐
play will successively turn green until theeve nt
shown is reached. The driv etra in will be set for
minimal energy consum ption. The vehicle will
re cuperate au tonomous lyand thus charge the
high-voltage batter y.
% You can also manually inc rease or reduce
re cuperation. Ho wever,ECO Assi stisavaila‐
ble on ly inthehà setting
(/ page 150). 15 6
Driving and pa rking

R
pressure point in the haptic accelerator
pedal
% In drive prog rams ; andÍ, an addi‐
tional pressu repoint is activated in the hap‐
tic accelera tor pedal.
R 1st pressu repoint: at appr ox. 50% pedal
tr ave l (only in ;andÍ)
R 2nd pressure point: transition tokick‐
down (alw aysav ailable)
Av ailable drive prog rams
= Individual
R The following vehicle characteristics are indi‐
vidually adjus table:
- drive
- suspension
- steering
C Sport
R maximum po werav ailability
R stability but with a sporty, dynamic setup
R only suit ablefor good road conditions, a dry
ro ad sur face and a clear stre tch of road A
Comfort
R com fortable driving style
R balance between traction and stability
R best balance between ef ficiency and per‐
fo rm ance for all driving situations
R recommended for all road conditions
; Eco
R economical setting of vehicle functions
R balance between traction and stability
R recommended for all road conditions
R 1st pressure point in the haptic accelerator
pedal indicates an ef ficient, economical driv‐
ing style.
R when thero ute option Electric Intelligence is
swit ched on and route guidance is active, a
ch equered flag in the speedome ter indica tes
th e maximum permissible speed recommen‐
ded byactive range moni toring . It is the driv‐
er's ownre sponsibility tocomply wi th them
in order toreach the next scheduled charging
st ation . Í
Í (MaxRange)
R maximum range and consu mption optimisa‐
tion
R particular lyefficient overrun mode and maxi‐
mum ef ficient recuperation in hÃ
R 1st pressure point in the haptic accelerator
pedal:
- automatically limits the speed tothe max‐
imum permissible speed de tected bythe
Tr af fic Sign Assi st
- additionally limits the speed tothe maxi‐
mum permissible speed recommended by
active range moni toring when thero ute
option Electric Intelligence is on andthe
ro ute guidance is active, in order toreach
th e next scheduled charging station.
% Ifth eTr af fic Sign Assi stdoes not de tect a
maximum permissible speed and range mon‐
itoring is inactive, the last specified maxi‐
mum permissible speed is used as the limit
speed. The maximum limit speed set bythe
1st pressu repoint is 140 km/h. 15 8
Driving and pa rking

The limit speed set
bythe 1st pressure point is
shown in the speedome ter.The segments
between the cur rently driven speed and the limit
speed light up in green. For ef ficiency reasons,
small deviations between the cur rently driven
speed and the limit speed are permitted.
If yo ustep on the accelera tor pedal be yond the
1st pressu repoint, the limit speed is deactiva‐
te d. The green segments in the speedome ter are
not shown. When the accelera tor pedal is posi‐
tioned in front of the 1st pressure point again,
th e limit speed is reactivated, thus making sure
th at the maximum permissible speed is main‐
ta ined again.
If a vehicle in front is de tected, the speed is
re duced in order tofollow theve hicle in front at
an adjus ted dis tance.
If th eve hicle de tects road and traf fic conditions
th at requ ire decele ration, theve hicle is no lon‐
ge r driven and coasts. Todecelerate theve hicle,
re lease the accelerator pedal. How much the
ve hicle automatically decelerates when the
accelerator pedal is released depends on the set
re cuperation le vel (/ page 150). In hÃ,
deceleration is auto matic wherethere are vehi‐ cles in front, traf
fic signs, roundabouts and
bends. In all other recuperation le vels, a perma‐
nently defined overrunto rque is se t. Ifthe situa‐
tion calls for it, you must also depress the brake
pedal rega rdless of the selected recuperation
le ve l.
If yo u activate theAc tive Dis tance Assi st
DISTRONIC or the cruise control in drive pro‐
gram Í, the limit speed is deactivated bythe
1st pressu repoint. If you deactivate the function
again, the limit speed set bythe pressure point
is switched on again.
If yo u also activate the limiter in drive program
Í, the speed is limited byboth Í andthe
limiter:
R ifth e speed stored in the limiter is higher
th an the limit speed of Í,theve hicle
accelerates up tothe speed stored in the lim‐
iter when you depress the accelera tor pedal
be yond the 1st pressure point. If you depress
th e accelerator pedal be yond the 2nd pres‐
sure point (kickdown), theve hicle continues
to accelerate without any limitation. R
ifth e speed stored bythe limiter is lo wer
th an or equal tothe limit speed of Í,then
th e speed is limited byboth th e 1st and the
2nd pressu repoints tothe speed stored by
th e limiter. If you depress the accelera tor
pedal be yond the 2nd pressure point (kick‐
down), theve hicle continues toaccelerate
without any limitation.
The functions of the drive program are only
to ols. The driver is responsible for maintaining a
suf ficiently safe di stance totheve hicle in front,
ve hicle speed and for braking in good time.
The function of the drive program may be restric‐
te d in thefo llowing situations:
R if visibility is poor, e.g. due toinsuf ficient illu‐
mination of thero ad, high lyvariable shade
conditions, rain, sno w,fog or heavy spr ay.
R ifth ere is glare, e.g. from oncoming traf fic,
di re ct sunlight or reflections.
R Ifth ere is dirt on the windscreen in the area
of the multifunction camera or the camera is
mis ted up, damaged or obscured. Driving and parking
15 9

j
Park position
k Reversege ar
i Neut ral
h Drive position
En gaging reve rsege ar R #
Depress the brake pedal and push the
DIRECT SELECT le ver upwards past thefirst
point of resis tance. En
gaging neutral N #
Depress the brake pedal and push the
DIRECT SELECT le ver up or down tothefirst
point of resis tance.
Subsequently releasing the brake pedal will
allow youto mo vetheve hicle freel y,e.g. topush
it or tow it away.
If yo uwa ntthe transmission toremain in
neutral N even if the ignition is switched off: #
start theve hicle. #
depress the brake pedal and engage neutral
i. #
release the brake pedal. #
switch the ignition off.
% ifyo uth en exitth eve hicle leaving theke y in
th eve hicle, the transmission remains in neu‐
tral i.
Engaging park position P #
Obser vethe no tes on parking theve hicle
(/ page 181). #
Depress the brake pedal until theve hicle
comes toast andstill. #
When theve hicle is stationar y,press button
j.
Pa rk position is only engaged when the
transmission position display jis shown in
th e driver displa y.If no transmission position
display jappears, secure theve hicle to
pr eve nt it from rolling away.
Pa rk position jis engaged automatically if one
of thefo llowing conditions is me t:
R You swit ch theve hicle off with the transmis‐
sion in position hork.
R You open the driver's door when theve hicle
is at a standstill or when driving at a very low
speed and the transmission is in position h
or k.
% Tomanoeuvre with an open driver's door,
open the driver's door while stationary and
engage transmission position hork
again.
% Ifyo u ha veengaged park position jor
switched off the drive sy stem and no trans‐
mission position display is displa yed, secure
th eve hicle from rolling away ( /page 186). 16 2
Driving and pa rking

Engaging drive position D
#
Dep ress the brake pedal and push the
DIRECT SELECT le ver down past thefirst
point of resis tance. Fu
nction of flexible all-wheel distribution
The flex ible all-wheel distribution means the
drive is alw ays ideally distributed between the
two axles. Depending on the situation, only the
front axle or only there ar axle can be driven, or
th e drive can be distributed continuously
between bo thaxles.
This allo ws the maximum recur rent delay tobe
achie ved (/ page149). The resulting recupera‐
tion increases theve hicle's range.
To get her with ESP ®
and 4ETS, theflex ible all-
wheel distribution impr ovesth e traction of your
ve hicle whene ver a driven wheel spins due to
insuf ficient traction.
If yo ufa ilto adapt your driving style, theflex ible
all-wheel distribution can neither reduce therisk
of accident nor override the la wsof ph ysics. It
cannot take into account road, weather or traf fic
conditions. The flex ible all-wheel distribution is only an aid.
You are responsible especially for
maintaining a safe dis tance from theve hicle in
front, forve hicle speed, for braking in good time
and forst ay ing in lane.
% In wint ryroad conditions, the maximum
ef fect of theflex ible all-wheel distribution
can be achie ved only if you use winter tyres
(M+S tyres), with sn ow chains if necessar y. Cha
rging the high-voltage bat tery Note
s oncharging the high-voltage bat tery *
NO
TEHigh-vol tage battery damage due
to leaving theve hicle idle for lengt hy
periods of time Lithium-ion batteries
experience a natural
self-dis charge.
Exhaustive discha rging can therefore occur if
th eve hicle is idle for se veral mon ths. This
can damage the high-voltage batter y. #
Toavo id damage, please obser vethe
fo llowing recommendations when han‐
dling the high-voltage batter y. *
NO
TEAccelerated ageing of the high-
vo ltage battery As a
result of its basic characteristics, the
st orage capacity of and the amount of energy
av ailable from the high-voltage battery
decreases overth e course of its life. There‐
fo re , bo th th e maximum electrical range that
can be achie vedby theve hicle and its maxi‐
mum electrical output can be impaired.
The following factors can accele rate the age‐
ing of the high-voltage battery:
R frequently fully charging (char gelevel
10 0%) the high-voltage batter y,especially
when this process is not directly follo wed
by a journey
R frequent rapid charging with direct cur‐
re nt (mode 4)
R leav ing theve hicle non-operational for
long periods at high ambient temp era‐
tures #
Toavo id accelerated ageing, please
obser vethefo llowing recommendations
when handling the high-voltage batter y. Driving and pa
rking 16 3

Combo 2
vehicle soc ket
1 Type 1 or type 2 connection forch arging
with alternating cur rent
2 Socketex tension forch arging with direct
cur rent
% When using a CCS (Combined Charging Sys‐
tem) charging cable tocharge with direct
cur rent at a combo vehicle soc ket, bo thvehi‐ cle soc
ket connections 1and 2are used
fo rch arging.
Charging options forth e high-voltage battery
(mode 2, 3 or 4):
R Charging thro ugh recuperation while the
ve hicle is in motion
R Charging with alternating cur rent when sta‐
tionary:
- Ata mains outlet (mode 2)
- Atawa llbox or charging station (mode 3)
R Charging with direct cur rent when stationary:
- Atafa st charging station (mode 4)
Depending on the count ry-specific vehicle equip‐
ment and your vehicle's charging cable, sin gle
phase ACcharging is also possible.
Obse rveth e dif fere nt grid requirements of your
cur rent location when charging. On lyuse charg‐
ing cables which con form tothe grid require‐
ments. Consult a qualified electrician or your
local grid operator if you ha veany questions.
It is recommended that youch arge the high-volt‐
age battery at a wallbox or charging station due to
the impr ovedch arging per form ance and bet‐
te rch arging ef ficiency of fere d.
Sy stem limits
The po wer output of the high-voltage battery
may be impaired bythefo llowing:
R High or low outside temp eratures
R Elect rical auxilia ryconsumers in theve hicle
being switched on, e.g. operating the air con‐
ditioning sy stem
R Exte nded pe riods without charging
The charging time of the high-voltage battery
may be increased bythefo llowing:
R High or low outside temp eratures
R Exte nded pe riods without charging
R The maximum available charge cur rent of the
ch arging facility
R The settings of thech arging process in the
multimedia sy stem (/ page180) Driving and parking
16 5