2008 RENAULT SCENIC display

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-36
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-36V9 MR-372-J84-87B000$086.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
1.4.3.7 Automatic gearbox computer (if fitted):
The computer informs the UCH of the selector position (park, neutral, etc.) via the multiplex network.
2 AIR CONDITIONING FUNCTION
The type of air conditioning control can be displayed by configuration reading LC013 Air conditioning type and
configured using command CF019 Air conditioning type (can be configured during configuration of the UCH
by the SC008 UCH type command).
2.1 Sub-function: USER SELECTION (Non-regulated air conditioning only)
The UCH receives the signal from the air conditioning panel via cable connection for the air conditioning request, for
electric heated rear screen and the signal for passenger compartment blower operation.
The UCH sends the request to the Protection and Switching Unit to start electric heated rear screen de-icing.
The UCH sends the request to the injection system to activate the air conditioning compressor.
The following statuses can be displayed:
–ET029 Air conditioning button.
–ET028 Heated rear screen button.
–ET015 Passenger compartment fan.
Operation of the indicator lights on the air conditioning and electric heated rear screen request buttons can be
checked using the following actuator commands:
AC015 Air conditioning button indicator and AC019 Heated rear screen indicator.
2.2 Sub-function: HEATING
The UCH manages the passenger compartment heating resistors (RCHs) by controlling power relays according to
the request for ventilation in the passenger compartment, the engine coolant temperature, the external temperature,
the electrical power balance, engine loading and, for the cabriolet version, if the roof is open.
The following statuses and parameters produced by the UCH can be displayed:
–PR001 Battery voltage.
–PR002 External temperature.
–ET015 Passenger compartment blower only with non-regulated air conditioning.
–ET017 Number of RCH*s required.
–ET018 Number of RCH*s authorised by alternator alternator charge rate.
–ET019 Number of RCH*s authorised by injection system.
–ET020 Number of RCH*s activated.
–ET021 RCH* 1 control.
–ET022 RCH* 2 control.
–ET031 Fast idle request for RCH.
–ET169 Engine.
–ET025 Retractable roof for cabriolet version only.
–ET026 Heated rear screen switch.
*RCH = Passenger Compartment Heating Resistors

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-37
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-37V9 MR-372-J84-87B000$086.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
Relay 1 controls a passenger compartment heating resistor unit consisting of one resistor.
Relay 2 controls a passenger compartment heating resistor unit consisting of two resistors.
Check the operation of the passenger compartment heating resistors using actuator commands:
AC016 RCH relay 1, AC017 RCH relay 2 and AC018 RCH relay 3.
The configuration can be displayed using LC030 Heating resistor types.
2.3 Sub-function: COLD LOOP
The UCH requests the injection to switch on the compressor via the multiplex network, depending on the external
temperature, the passenger compartment blower activation signal and whether the engine is in operation. The
following statuses and parameters can be displayed:
–ET030 Air conditioning request 2.
–ET169 Engine.
–ET015 Passenger compartment fan.
–PR002 External temperature.Passenger compartment
heating resistor powerRelay 1 Relay 2
0 W 0 0
333 W 1 0
667 W 0 1
1000 W 1 1

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-38
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-38V9 MR-372-J84-87B000$129.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
3 WIPER FUNCTION
3.1 Sub-function: WIPER CONTROL
The UCH receives the driver's request when the wiper stalk is used.
Windscreen wiper:
The UCH requests the Protection and Switching Unit via the CAN network to supply power to the windscreen wiper.
The park position is managed by the Protection and Switching Unit.
The wiper control stalk has four positions (neutral, intermittent wiping, slow speed and fast speed) and a wiper
intermittent speed ring which varies the time between each wipe.
Special notes:
If the windscreen wiper is set to low speed when the vehicle is moving and then the vehicle stops, the system switches
to intermittent wipe.
The requests made to the UCH by the wiper stalk can be displayed using statuses: ET077 Wiper stalk position and
ET096 Wiper intermittent speed ring.
If the vehicle is fitted with a rain sensor, (see special features of the rain and light sensor).
Rear screen wiper:
Rear wiper speed and power supply are also controlled by the UCH.
Windscreen wiper outside neutral position:
–The rear screen wiper starts to operate as soon as reverse gear is engaged and rain drops are detected on the
windscreen wiper.
–When the vehicle is stationary, the wipers operate intermittently every 7 seconds; over 36 mph (60 km/h) they
operate every 3 seconds. There is no continuous wiping function, except during the rear screen washer control.
The statuses corresponding to operation of the rear screen wiper can be displayed using statuses ET080 Rear
screen wiper request, ET097 Rear screen wiper park position and ET109 Reverse gear engaged or ET108
Automatic gearbox lever position, by configuration reading LC064 Rear screen wiper and by configuration
CF166 Rear screen wiper.
Windscreen washers:
The front and rear windscreen washers are controlled directly by the wiper control stalk, via a wire connection.
These connections are doubled up to the UCH to permit command status reading.
ET078 Windscreen washer request,
ET079 Rear screen washer request.
Special features of headlight washers
For vehicles fitted with xenon bulbs, the headlight washers are actuated at the same time as the windscreen washer,
only if the headlights are on.
Two cases are possible concerning the control of the headlight washers.
First case: (vehicles fitted with a SIEMENS Vdiag 44 UPC): the UCH sends the command by cable to two headlight
washer relays on a relay plate underneath the UPC.
Second case: (vehicles fitted with a LEAR Vdiag 48 or later): the UCH requests the UPC via the multiplex network to
activate the washer relays.
WARNING
If the UCH does not manage to determine the position of the control stalk, or inform the Protection and Switching
Unit of the control stalk's position, the Protection and Switching Unit will activate the windscreen wiper at low speed
(defect mode).
MR-372-J84-87B000$129.mif

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-39
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-39V9 MR-372-J84-87B000$129.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
3.2 Sub-function: WIPER POWER
The UCH controls the rear screen wiper's power (and that of the headlight washers if the vehicle is fitted with xenon
headlights and a SIEMENS Vdiag 44 UPC).
Their operation can be checked using commands AC007 Rear screen wiper, AC030 Headlight washer relay 1
and AC031 Headlight washer relay 2.
Rain and light sensor
Information displays Multiplex network
Steering column
control
UCH Protection and
Switching Unit
Rear screen wiper Rear screen wiper
Windscreen and rear
screen washers
Headlight
washers

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-40
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-40V9 MR-372-J84-87B000$129.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
3.3 Special features of the rain sensor (if fitted to the vehicle)
The rain and light sensor is a single sensor, connected to the UCH by a single connection. This sensor is installed on
the windscreen.
The rain sensor enables the windscreen wipers to be operated automatically and controls the wiper speeds according
to the quantity of water on the windscreen.
The sensor is activated by setting the wiper stalk to AUTO position.
Depending on the vehicle's bodywork, two cases are possible for the operation of the rain sensor:
a) Phase 1 bodywork:
Automatic operation of the rain sensor is inhibited following ignition switch-off with the wiper stalk in the Auto position.
To reactivate operation when next switching on the ignition, set the wiper control stalk in the neutral position then
return it to the Auto position.
b) Phase 2 bodywork:
Automatic operation of the rain sensor remains active following ignition switch-off with the wiper stalk in the Auto
position.
For a vehicle which is fitted with a rain sensor, with automatic detection activated, the rear screen wiper starts to
operate if reverse gear is engaged and if the sensor has detected rain for more than 1 minute.
The wiper intermittent speed ring is used to modify the sensor's sensitivity to rain and therefore the time
between wipes.
When the vehicle is not fitted with a rain sensor, the intermittent speed position on the control stalk takes the place of
the Auto position.
The status ET118 Rain sensor sensitivity ring position can be interpreted if the vehicle is configured with rain
sensor and inhibits status ET096 Intermittent wipe ring position.
The operation of the rain sensor can be displayed using status ET114 Wiper request by rain sensor, and by
configuration reading LC044 Rain/light sensor.
Configuration CF035 Rain/light sensor is available during UCH configuration (SC008 UCH type) (see
Configurations and programming). Information displays Rain and light sensor Multiplex network
Steering
column
control UCH Protection and Switching Unit
Side lights Windscreen wiper
Dipped headlights
Main beam headlights

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-43
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-43V9 MR-372-J84-87B000$129.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
4FUNCTION: LIGHTING
4.1 Sub-function: LIGHTING CONTROL
The UCH receives the request from the driver, from the lighting stalk, from the hazard warning lights button and, if
fitted to the vehicle, from the light detector.
The UCH requests the Protection and Switching Unit, via the multiplex network, to provide power to the side lights,
dipped headlights, main beam headlights and fog lights (front).
If a request to activate the lighting is made, the UPC provides power to the xenon bulb computers.
The dipped headlights are still supplied when the main beam headlights are activated.
The following statuses can be displayed:
ET081 Lighting stalk position.
ET082 Rear fog lights request.
ET085 Hazard warning lights switch.
ET083 Left-hand direction indicator request.
ET084 Right-hand indicator request.
If the UCH cannot determine the position of the control stalk, or inform the Protection and Switching Unit of the
control stalk's position, the Protection and Switching Unit will activate the dipped headlights.
4.2 Sub-function: LIGHTING POWER
The UCH controls the power supply for the rear fog light (a single one), direction indicators and interior lighting (roof
lights and footwell/floor lights).
The interior lighting request can be displayed using the ET112 Interior lighting control status.
Operation of the lights powered by the UCH can be checked using the actuator commands AC009 Rear fog lights,
AC022 Left-hand direction indicator, AC023 Right-hand direction indicator, AC021 Interior lights and AC027
Footwell/floor lighting.
Information displays Rain and light sensor Multiplex network
Steering column
controlUCHProtection and Switching
Unit
Rear fog light
Direction indicators
Interior lighting
Side lightsMain beam
headlights
Dipped
headlightsFront fog lights

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-45
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-45V9 MR-372-J84-87B000$129.mif
4.4 Special features of the light sensor (if fitted to the vehicle).
Information displays Rain and light sensor Multiplex network
Steering column
controlUCHProtection and Switching
Unit
The rain and light sensor is a single sensor, connected to the UCH by a single connection. This sensor is installed on
the windscreen.
The light sensor enables the side lights and dipped headlights to be operated automatically as soon as the vehicle is
in a dark place (tunnel, night, gloomy weather conditions, etc.).
The status of the light sensor can be displayed using ET115 Lights on request by light sensor, and by configuration
reading LC044 Rain/light sensor.
Configuration CF035 Rain/light sensor is available during UCH configuration SC008 UCH type (see
Configurations and programming).
To activate the automatic lighting function, press the AUTO button on the lighting stalk for at least 4 seconds. This
action is confirmed by two beeps.
To deactivate the automatic lighting function, switch the engine off and press the AUTO button on the lighting stalk
for at least 4 seconds. A beep confirms this action and the message Automatic lighting OFF appears on the
instrument panel.
Any other operation on the lighting stalk overrides and cancels automatic operation.
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
Side lightsWindscreen
wiper
Dipped
headlights
Main beam
headlights

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-46
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-46V9 MR-372-J84-87B000$129.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
5. TYRE FUNCTION
SYSTEM COMPOSITION
The tyre pressure monitor system consists of the following components:
–four sensors (one on each wheel but not on the spare wheel),
–a computer (UCH),
–an instrument panel display for the driver.
WARNING:
It is forbidden to install PAX System tyres on a vehicle without PAX System tyres as standard.
In the MEGANE II family, PAX System tyres can only be installed on the 5-seat SCENIC II.