servo assist, for example, if
running without the
combustion engine.
Advise the customer that this
protects the separating clutch
between the combustion
engine and electric motor.

All comfort functions provided
by the ancillary consumers
need to be maintained for the
customer.

Advise the customer that this
aids fault-free running of the
combustion engine.

Advise the customer that this
protects the battery.

If the battery is fully charged
by a lengthy recuperation
phase, for example, no more
electric thrust (simulation of
Deceleration takeover active
the combustion engine's thrust
by the electric motor) can be
set. To ensure a consistent
driving feel, the engine is then
activated and set at this thrust.
The engine must be run at
certain interval for a defined
Motor protection active
time in order to protect the
engine components.
To prevent the fuel from
clogging, due to inappropriate
consistency (cold), the fuel
Fuel clogging protection active
must be used up and
intermingled with topped-up
fuel.
A component of the exhaust
system requires a defined
Exhaust system diagnosis
temperature/exhaust gas flow
for self-diagnosis.
A component of the exhaust
Exhaust emission control
gas cleaning system requires a
diagnosis
defined temperature/exhaust
gas flow for self-diagnosis.
A component of the air system
in the engine requires a
Diagnosis of air system
defined air flow/air pressure
for self-diagnosis.
A thermostat in the engine
Test of thermostat not
requires a defined temperature
complete
for self-diagnosis.
The temperature of one or
more component(s) of the
Cat. heater
catalytic converter system
is/are outside the regular
operating range.
The engine needs to be
Intermittent function
running for adaptations and
restriction
diagnostics, as well as for
component protection
Event memory entry in engine
.
control module
Restriction in start system
.

Advise the driver of this
comfort feature. The vehicle
would otherwise disable
"engine braking" when driving
downhill.

Advise the customer that this
protects the engine
components.
Advise the customer that this
protects the engine
components and vehicle.
Advise the customer that for
assured diagnosis the engine
must not be stopped.
Advise the customer that for
assured diagnosis the engine
must not be stopped.
Advise the customer that for
assured diagnosis the engine
must not be stopped.
Advise the customer that for
assured diagnosis the engine
must not be stopped.
Advise the customer that the
operational readiness of
emissions-related components
must always be ensured as a
legal requirement.
Advise the customer that for
safe execution the engine must
not be stopped.
.
.

Start prevention
Reason

Cause:

Engine hood open

Engine hood open

Function locked due to
excessive stalling

If excessively frequent stalling
is detected, the coordinator
disables start/stop mode in
order to protect components

Brake pedal information,
plausibility

Start prohibition due to lack of
brake plausibility.

Handling
Advise the customer that
start/stop is disabled for his
safety when the bonnet is open
(also in hybrid vehicle).
Advise the customer that this
will help protect the engine
As long as the brake has not
yet been initialised, starting of
the combustion engine is
inhibited.

02 - Gearbox electronics
Start requests
Reason
Driver intention

Vehicle speed too high

Auxiliary hydraulic pump for
transmission error

Stop prohibitions
Reason
Temperature condition not met

Pressure sensor failure

Emergency running /
Restricted function

Cause:
Gear P engaged; P can only be
disengaged when engine
running (oil pressure)
Without the engine running,
the necessary lubrication of the
gearbox is lacking at high
speed
The gear oil auxiliary
hydraulic pump has a
malfunction.

Cause:
The gear oil temperature was
below -10°C

Handling
Advise the customer that
placing the selector lever in P
starts the engine.
Advise the customer that at
high speed the engine must be
running in order to lubricate
the gearbox.
Check gear oil auxiliary
hydraulic pump by final
control diagnosis and repair
possible faults.

Handling
Advise the customer that at
very low temperatures the
gearbox needs to be warmed
up first

When the sensor fails, the
hydraulic pump motor -V401
operates continuously
providing hydraulic pressure;
Repair gearbox
during the “stop phase” this
would overload the vehicle
electrical system
In the event of a fault only a
partial gearbox is used. So stop Repair gearbox
function cannot be

implemented
Software/application error
Gear actuator in wrong
position

Data record error, stop
function permanently off
While the gear actuator is
being moved to the correct
position, the engine must be
running to maintain the
pressure supply

Transmission fluid
temperature too high

Excessive gear oil temperature
permits no stop function

Adaption procedure active

The mechatronics unit is
continuously being adapted in
operation

Brake acceleration too great
Pressure accumulator filling
not completed

Excessive braking was applied
in operation and the gear oil
level has fallen
Sufficient pressure has not
been produced in the pressure
accumulator for operation

Oil temperature too low

Too low gear oil temperature
permits no stop function

Gear 1 or 2 not selected

The gear engaged by the
automatic gearbox at standstill
must be 1 or max 2!

Clutch temperature load too
high

Excessively high clutch
temperature permits no stop
function.

Hydraulic fluid, pressure
supply not assured

The gear oil auxiliary
hydraulic pump has a
malfunction.

03 - Brake Electronics
Start requests
Reason

Cause:

Hill descent control HDC /
HDC button pressed

Activation of hill descent
control

Check software version
(SVM)
Inform the customer that
improper motions on the
selector lever and result in
unnecessary gear selector
motions
Advise the customer that if the
gearbox is overheated the stop
function is not possible
Advise the customer that the
gearbox continuously
improves its gear-shifting
comfort autonomously, and in
this cycle the engine cannot be
stopped
Advise the customer that
excessive braking may prevent
an engine stop
Advise the customer that the
gearbox must build up
pressure for restarting
Advise the customer that if the
gearbox is too cold the stop
function is not possible
Repair gearbox.
Advise the customer that
driving under high load will
result in high clutch
temperatures
Check gear oil auxiliary
hydraulic pump by means of
final control diagnosis and
repair possible faults.

Handling
Explain to the customer that
when hill descent control is
active start-stop is not possible
in certain driving situations

AUTO HOLD slip detection /
slipping vehicle detected

Sliding vehicle detected.

Roll-back detected

Rolling back vehicle detected

System malfunction

A system error is entered if the
control unit detects
undervoltage or if the vacuum
sensor of the brake servo unit
is faulty

Offroad mode active

At low speeds it may be that
not enough vacuum is
generated

Road surface incline too high

Road gradient too great

ASR and ESP button operated

ESC-Off button pressed to
activate ESC driving modes

Stop prohibitions
Reason

Emergency braking / Hard
deceleration to standstill

AUTO HOLD slip detection /
slipping vehicle detected

Cause:
If the ABS cuts in, in the event
of heavy braking, or if the
electronic parking brake (EPB)
is operated down to a
standstill, the ESP is intended
to prevent the engine stopping
for a certain time
Sliding vehicle detected

Explain to the customer that if
the vehicle is sliding it should
be immediately started up (as
servo and braking force
assistance is provided only
with the engine running).
Explain to the customer that if
the vehicle is rolling back it
should be immediately started
up (as servo and braking force
assistance is provided only
with the engine running)
Advise the customer that if
there is undervoltage the
engine needs to be running
Advise the customer that there
must be brake vacuum when
driving off-road even at low
speeds in order to maintain
braking response
Explain to the customer that in
order to ensure comfortable
start-stop driving (e.g. engine
running for fast drive-off,
brake assistance) the
permissible road gradient is
limited
Explain to the customer that
pressing the ESC OFF button
selects a specific ESC driving
mode (e.g. ESC Off, offroad),
so start-stop is not possible for
operational reasons

Handling
Explain to the customer that
the vehicle should be
maintained ready to drive after
emergency braking
Explain to the customer that if
the vehicle is sliding it should
be immediately started up (as
servo and braking force

assistance is provided only
with the engine running)

Roll-back detected

Rolling back vehicle detected

System malfunction

A system error is entered if the
control unit detects
undervoltage or if the vacuum
sensor of the brake servo unit
is faulty.

Hill descent control HDC /
HDC button pressed

Activation of hill descent
control

Brake control unit pump
operation

Brake control unit pump
running.

Offroad mode active

At low speeds it may be that
not enough vacuum is
generated

Deactivation of start/stop
function in brake control unit

The start/stop function was
deactivated by the adaption

Road surface incline too high

Road gradients too great

ASR and ESP button operated

ESC-Off button pressed to
activate ESC driving modes

Explain to the customer that if
the vehicle is rolling back it
should be immediately started
up (as servo and braking force
assistance is provided only
with the engine running)
Advise the customer that if
there is undervoltage the
engine needs to be running
Explain to the customer that
when hill descent control is
active start-stop is not possible
for operational reasons
Explain to the customer that if
the brake control unit pump is
running, start-stop is not
possible in order to safeguard
key driving dynamics
characteristics.
Advise the customer that there
must be brake vacuum when
driving off-road even at low
speeds in order to maintain
braking response
.
Explain to the customer that in
order to ensure comfortable
start-stop driving (e.g. engine
running for fast drive-off,
brake assistance) the
permissible road gradient is
limited in discrete increments
Explain to the customer that
pressing the ESC OFF button
selects a specific ESC driving
mode (e.g. ESC Off, offroad),
so start-stop is not possible for
operational reasons

08 - Air conditioner/heater electronics
Start requests
Reason
Cause:
PSD (permissible stop
There is a fault in the AC.
duration) emergency running
Therefore only a permissible
elapsed / PSD with active
stop duration of approx. 45
DTC
seconds is specified.

Epsilon (output) blow-out
temperature too low or too
high

Air conditioner not yet at
steady state

Defrost active

Customer has pressed the
Defrost button.

Ambient temperature too low
or too high

Ambient temperature outside
nominal range

Epsilon (output) interior
temperature too low or too
high

Customer temperature request
too low/high

Gradient dew point interior too The rise in air humidity is too
high
high
Risk of misting

Risk of windscreen misting

At least one specified
temperature is High or Low

Customer AC setting High or
Low

Comfort humidity

Interior humidity ideally 50...
60%

PSD (permissible stop
duration) "Epsilon_Fog"
elapsed *)

Risk of windscreen misting

PSD (permissible stop
duration) "Manual air

Customer setting manual air
recirculation