2008 RENAULT SCENIC light

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Introduction87B
87B-2
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Introduction87B
87B-2V9 MR-372-J84-87B000$043.mif
187B
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Introduction
1. SCOPE OF THIS DOCUMENT
This document presents the fault finding procedure applicable to all computers with the following specifications:
2. PREREQUISITES FOR FAULT FINDING
Documentation type:
Fault finding procedures (this document):
–Assisted fault finding (integrated into the diagnostic tool), Dialogys.
Wiring Diagrams:
–Visu-Schéma (CD-ROM), paper.
Type of diagnostic tools:
–CLIP
Special tooling required:
3. REMINDERS
Procedure
To run fault finding on the vehicle computers, switch on the forced + after ignition feed.
Proceed as follows: Vehicle(s): Mégane II, Scénic II
Function concerned: UCHName of computer: UCH
Vdiag No.: 44, 48, 4C, 4D, 4F, 50.
Special tooling required
Multimeter
Elé. 1681 Universal bornier
Switch on the forced + after ignition feed:
–with the vehicle card in the card reader,
–press and hold start button (longer than 5 seconds) with start-up conditions not fulfilled,
–connect the diagnostic tool and perform the required operations.
Switching off the forced + after ignition feed:
Press the Start button twice briefly (less than 3 seconds).
ensure that the + after ignition feed has been cut off by checking that the computer indicator lights on the instrument
panel have gone out.
UCH_V44_PRELI /UCH_V48_PRELI/UCH_V4C_PRELI/
UCH_V4D_PRELI/UCH_V4F_PRELI/UCH_V50_PRELI
MR-372-J84-87B000$043.mif

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Introduction87B
87B-5
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Introduction87B
87B-5V9 MR-372-J84-87B000$043.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
4. FAULT FINDING PROCEDURE (continued)
Wiring check
Fault finding problems
Disconnecting the connectors and/or manipulating the wiring harness may temporarily remove the cause of a fault.
Electrical measurements of voltage, resistance and insulation are generally correct, especially if the fault is not
present when the analysis is made (stored fault).
Visual inspection
Look for damage under the bonnet and in the passenger compartment.
Carefully check the fuses, insulators and wiring harness routing.
Look for signs of oxidation.
Physical inspection
While manipulating the wiring harness, use the diagnostic tool to note any change in fault status from stored to
present.
Make sure that the connectors are properly locked.
Apply light pressure to the connectors.
Twist the wiring harness.
If there is a change in status, try to locate the source of the fault.
Inspection of each component
Disconnect the connectors and check the appearance of the clips and tabs, as well as the crimping (no crimping on
the insulating section).
Make sure that the clips and tabs are properly locked in the sockets.
Check that no clips or tabs have been dislodged during connection.
Check the clip contact pressure using an appropriate model of tab.
Continuity, insulation and resistance check
Check the continuity of entire lines, then section by section.
Look for a short circuit to earth, to + 12 V or with another wire.
If a fault is detected, repair or replace the wiring harness.

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-7
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-7V9 MR-372-J84-87B000$086.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
General operation:
The UCH is involved in the following five functions (shared between several computers):
1/ Access-safety function
This function is divided into three sub-functions: Access, Protection and Starting.
2/ Air-conditioning function
This function is divided into three sub-functions, which are: User selection, Heating and Cold loop (see: 62A, Air
conditioning).
In this function, the UCH manages the triggering of the passenger compartment heating resistor control relays, as
well as the heated rear screen and air conditioning indicator lights.
3/ Wiping function
This function is divided into two sub-functions, which are: Wiper control and Wiper power.
4/ Lighting function
This function is divided into two sub-functions, which are: Lighting control and Lighting power.
5/ Tyre function
This function is divided into three sub-functions which are: Tyre reception, Tyre management and Tyre display.
MR-372-J84-87B000$086.mif
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-11
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-11V9 MR-372-J84-87B000$086.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
f/ Display:
Unlocking is indicated by 1 flash of the direction indicators.
Locking is indicated by 2 flashes of the direction indicators.
When using the "boot status toggle" switch, display is not performed if a toggle request is made when the vehicle is
completely unlocked. In fact, in this case, the vehicle is not locked as only the boot is locked.
If one of the opening elements is detected as open when the request for locking the vehicle is made, the UCH will not
authorise vehicle locking and no indicators will flash to warn the user.
1.1.2 procedure of locking/unlocking by pressing the central door locking button:
This button is used to lock/unlock the vehicle while stationary or moving.
This button has no effect if the vehicle has been locked using the card in hands-free or manual mode.
Pressing the electric central door locking button when a door is unlocked will lock all the doors and the electric
central door locking indicator light will light up. Status ET044 CPE* button may be used to check that the button is
operating correctly.
The operation of the electric central door locking indicator light can be checked using command mode AC020 CPE*
button indicator light.
1.1.3 Principle of automatic locking when driving (RAID* system):
The Automatic Locking when Driving (RAID) function locks the vehicle as soon as the speed signal is above
approximately 4 mph (7 km/h).
Activation or deactivation of the RAID function can be viewed using ET043 RAID* function authorisation by CPE*.
The RAID function can be activated or deactivated by pressing and holding the electric door locking button for
approximately 5 seconds while the engine is running. Acknowledgement is indicated by a buzzer.
1.1.4 Principle of automatic relocking:
Automatic relocking takes place 2 minutes after hands-free or card unlocking if unlocking is not followed by the
opening of a door.
CPE*: Electric central door locking
RAID*: Renault Anti-Intruder Device Note:
Unlocking can be performed by the UCH if the airbag computer has detected an impact or if it is faulty (not
recognised on the multiplex network, internal fault, etc.). (see 88B, Multiplexing).

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-15
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-15V9 MR-372-J84-87B000$086.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
1.1.6 Principle of Electric Childproof Locking:
The UCH controls the rear door locks to prevent them from being opened by means of the interior door handles and
inhibits operation of the rear electric window switches.
The switch statuses and the activation of electric childproof locks can be viewed using the following statuses:
–ET233 Child safety lock switch,
–ET159 Rear left-hand door child safety lock,
–ET160 Rear right-hand door child safety lock.
The configuration Child safety lock can be read using configuration LC035 Child safety lock and modified (see
Configurations and programming) using the specific command SC016 Child safety lock (Vdiag 4C, 4D, 4F and
50).
Fault finding can be performed on the child safety lock switch indicator light using command AC076 Child safety
lock indicator light.
1.1.7 Principle of Deadlocking:
The UCH controls the door locks to prevent unlocking via the interior handles. This function is activated by pressing
and holding (+ 2 seconds) the Renault card's locking button or by pressing the door locking button twice.
The direction indicators flash rapidly three times for deadlocking (in addition to the two flashes for locking).
For this function to operate, the vehicle must have deadlocking (2 motors) and configuration LC003 Deadlocking
must be WITH (see Configurations and programming). Deadlocking is configured using CF009 Deadlocking.
The source of the last deadlocking activation/deactivation can be viewed using statuses ET088 Deadlocking
activation source and ET090 Deadlocking deactivation source.
It is impossible to deadlock the vehicle if the + accessories feed is active, if the lights are switched on or if the hazard
warning lights are activated.
1.1.8 The valet card function, specific to certain countries (e.g. Mexico):
This function controls the valet card option which enables vehicles fitted with it to separately control unlocking of the
driver's door, the boot, or the passenger doors and the glovebox.
When the vehicle is electrically pre-equipped with the valet option and this option has been configured, the cards can
be used in two different customer modes. The "master" cards can unlock all the opening elements, but the "valet"
cards cannot unlock the glovebox, the boot and the passenger opening elements. They can only start the vehicle,
lock the whole vehicle, and unlock the driver's door. The function is configured with CF085 Valet card function
using the specific command SC008 UCH type. To access CF085, configure CF036 Selective opening element
opening to WITH.
To check that this function has been configured correctly, use LC016 Card valet function.

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-22
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-22V9 MR-372-J84-87B000$086.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
1.1.13 Principle of automatic window relift:
When the doors are locked, and the lock button on the card is pressed twice in succession (or the door or boot if
the vehicle is fitted with hands-free function), the windows close automatically (as well as the sunroof, if fitted to
the vehicle).
The function is available on certain vehicles (see table below) depending on the number of one touch windows on
the vehicle and depending on the bodywork phases.
The automatic window relift function cannot be configured separately; it is automatically configured during special
command SC008 UCH type according to the vehicle type, number of one-touch windows and the production number
type.
1.1.14 Principle of new vehicle storage mode:
The vehicle is configured in this mode when it leaves the factory to optimise its power consumption:
–The immobiliser warning light is inhibited.
–The direction indicator warning lights are lit continuously on the instrument panel.
Before delivering the vehicle to the customer, deactivate this mode:
–By flipping down the steering column controls with the after ignition feed off.
–Or using command VP016 Deactivate new vehicle storage mode.
This function can only be activated in the factory with UCH Vdiag 4F or 50.If Then
Vehicle type One-touch window(s)Production
number typeFunction of automatic
window relift:
All except cabriolet phase 1 and 2
bodyworkWITHOUT WITHOUT
4-door phase 1 bodywork 1 driver OTW Jxxxxxx WITHOUT
4-door phase 1 bodywork 1 driver OTW OTHERS WITH
All except cabriolet and 4-door phase
1 bodywork1 driver OTW WITH
All except cabriolet phase 2 bodywork 1 driver OTW WITHOUT
All except cabriolet phase 1 and 2
bodywork2 or 4 OTW WITH
Cabriolet phase 1 and 2 bodywork WITHOUT WITHOUT

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-27
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-27V9 MR-372-J84-87B000$086.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
1.2.4 Renault card check by the UCH:
a/ Card check:
When the engine is running, the UCH checks for the presence of the Renault card in the passenger compartment (if
vehicle is hands-free) or in the card-reader when a door is opened then closed. If the Renault card is not detected, a
message on the instrument panel and a buzzer warn the driver.
Command AC036 Internal aerial test is used to check the area covered by the starting aerials inside the passenger
compartment (hands-free vehicles). The card reader flashes when the card is detected.
This command allows a hands-free card to be recognised even if it does not belong to the vehicle.
b/ Low battery warning:
If the Renault card battery is faulty or flat, the change card battery message is displayed on the instrument panel
when the vehicle is started, if there have been 5 attempts to authenticate the Renault card since the battery fault.
c/ Storing information on the card:
A device allowing information relating to the vehicle to be read from the card is available.
Information available: – VIN (Vehicle Identification Number).
–Mileage.
–Fuel level.
–Mileage before oil change.
–Tyre pressure (if vehicle fitted with SSPP).
–Status of OBD warning light.
–Oil level.
2.5 Immobiliser warning light programs
Immobiliser warning light Vehicle protection status
Ignition
offWarning light flashes slowlyVehicle protected (immobiliser active or fault with
steering lock)
Warning light not lit New vehicle or blank UCH storage mode
Ignition
onWarning light flashes slowly Renault card not recognised
Warning light continuously lit Injection authentication fault
Warning light not lit Vehicle unprotected (immobiliser inactive)

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