2008 RENAULT SCENIC Passenger Comparment Connection Unit Workshop Manual

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-33
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-33V9 MR-372-J84-87B000$086.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
1.4.1.6 The door locking motors:
These are direct current motors (12 V supply). The door locking motors are controlled by the UCH.
The deadlocking function requires a second motor per door.
1.4.2 Main components of the PROTECTION sub-function:
The protection sub-function is based on 4 main coded components:
–The Renault cards.
–The UCH.
–The electric steering column lock.
–The injection computer.
These parts are coded definitively: a part coded for one vehicle may not be used on another vehicle.
It is possible to replace a coded part with an uncoded part using special procedures in the CLIP tool and the vehicle
repair code (See Configuration and programming).
1.4.2.1 The Renault card:
The Renault card enables the vehicle to be started in two modes:
–starting by inserting the card into the reader:
–hands-free starting without insertion of the card into the card reader (hands-free vehicles).
The Renault card is powered by a 3 V battery. This battery is necessary to operate in standard and hands-free mode.
If the battery is too old, or if the vehicle is in an area of frequency interference, hands-free starting is not possible, but
always possible by inserting the Renault card into the reader.
1.4.2.2 The UCH:
a) The UCH detects the starting request (Start button pressed under starting conditions).
b) The UCH authenticates the Renault card via the starting aerials for hands-free mode, or via the card reader for
transponder mode.
c) The UCH manages the exchange with the steering column lock:
The UCH sends an unlocking request to the steering column via the vehicle's multiplex network, and the steering
column responds with the status of the lock bolt.
d) The UCH requests activation of the + after ignition feed from the Protection and Switching Unit.
e) The UCH manages the exchange with the injection computer:
The UCH and the injection computer exchange their codes via the vehicle's multiplex network to deactivate protection
and unlock the immobiliser.
f) The UCH requests the Protection and Switching Unit to supply the starter motor.

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-34
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-34V9 MR-372-J84-87B000$086.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
1.4.2.3 The electric steering column lock:
The electric steering column lock is controlled by the UCH. The steering column lock works by inserting and
removing a lock bolt. It replaces the Neimann type lock.
The steering column lock is powered outside + after ignition feed. The steering column lock supply is via the after
ignition relay (located in the Protection and Switching Unit) in its rest position, from where it is distributed to the
column lock by the UCH.
The UCH sends an unlocking request and a code to the steering column lock, via the vehicle's multiplex network.
The multiplex network unlocks the steering column lock if the code is recognised.
A sensor located on the column lock bolt informs the UCH, via the multiplex network and by wire connection, that it
is unlocked.
When unlocking is confirmed, the UCH activates the + after ignition feed via the Protection and Switching Unit. The
column lock is no longer supplied.
The column lock has a "+ after ignition feed present on vehicle" wire signal which inhibits locking while the feed is
active.
1.4.2.4 The injection computer:
The injection computer is coded and unlocks following the encrypted challenge exchange with the UCH.
1.4.2.5 The starting aerials (hands-free vehicles):
There are 3 transmitter aerials located in the passenger compartment. They are controlled by the UCH to interrogate
the card during a starting request or in confirming the presence of the card in the vehicle (e.g. after a door is
opened).
The power used allows the whole passenger compartment to be covered, including the boot. Overspill outside the
passenger compartment is minimal.
1.4.2.6 The card reader:
The card reader is connected to the UCH by a wire connection. It provides the transponder function (like a key
recognition ring). It therefore allows authentication of a Renault card without a battery.
If the card is not detected or recognised during hands-free starting, the card reader flashes to tell the customer to
insert the Renault card.IMPORTANT IMPORTANT
The steering column lock is:
–not removable when the bolt is disengaged,
–fitted with a left-hand thread self-shearing mounting bolt.

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-35
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-35V9 MR-372-J84-87B000$086.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
1.4.3 Main components of the STARTING sub-function:
The starting sub-function is based on the following main factors:
–The starting conditions being present.
–Passenger Compartment Control Unit (UCH).
–The automatic gearbox computer (if fitted on the vehicle).
–The Protection and Switching Unit.
1.4.3.1 Start button:
The start button transmits the driver's requests to start or stop the engine to the UCH.
1.4.3.2 The UCH:
The UCH ensures that the starting conditions are met, and that no other computer on the multiplex network is
inhibiting starting of the vehicle.
If the conditions are met, it requests control of the starter from the UPC.
1.4.3.3 The Protection and Switching Unit (UPC):
The Protection and Switching Unit activates the starter motor following a request from the UCH via the multiplex
network.
1.4.3.4 Neutral sensor (manual gearbox):
Informs the UCH of the position of the gearbox (neutral or gear engaged).
1.4.3.5 Clutch switch (manual gearbox):
Sends clutch pedal depressed signal (end of travel) to the UCH.
1.4.3.6 Brake switch:
Sends brake pedal depressed signal to the UCH.
Operation:
The unknown status does not automatically require the brake pedal to be replaced, because it is a temporary
operating status between released pedal status and depressed pedal status (see diagram above).

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