2008 RENAULT SCENIC ESP

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Introduction87B
87B-3
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Introduction87B
87B-3V9 MR-372-J84-87B000$043.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
Faults
Faults are declared present or stored (depending on whether they appeared in a certain context and have
disappeared since, or whether they remain present but are not diagnosed within the current context).
The present or stored status of faults should be taken into consideration when the diagnostic tool is used after the
forced + after ignition feed is switched on (without acting on the system components).
For a present fault, apply the procedure described in the Interpretation of faults section.
For a stored fault, note the faults displayed and apply the instructions in the Notes section.
If the fault is confirmed when the instructions in the Notes section are applied, the fault is present. Deal with the
fault.
If the fault is not confirmed, check:
–The electric lines on which there is a fault;
–The connectors on those lines (corrosion, bent pins, etc.);
–The resistance of the faulty component;
–The condition of the wires (insulation melted or split, chafing, etc.).
Conformity check
The aim of the conformity check is to check data that does not produce a fault on the diagnostic tool because the
data is inconsistent. Therefore, this stage is used to:
–carry out fault finding on faults that do not have a fault display, and which may correspond to a customer complaint.
–check that the system is operating correctly and that there is no risk of a fault recurring after repairs.
This section gives the fault finding procedures for statuses and parameters and the conditions for checking them.
If a status is not behaving normally or a parameter is outside the permitted tolerance values, consult the
corresponding fault finding page.
Customer complaints - Fault finding chart
If the test with the diagnostic tool is OK but the customer complaint is still present, the fault should be processed by
customer complaints.
A summary of the overall procedure to follow is provided on the following page in
the form of a flow chart.

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-12
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-12V9 MR-372-J84-87B000$086.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
1.1.5 Principle of hands-free locking/unlocking:
1Passenger side optical sensors.
2Driver side optical sensors.
3Door handle and boot locking switches.
4Boot/rear screen opening switch.
5Access aerials.
6Opening element locking motors.
7Renault card.
a/ Main components of the hands-free function:
–Renault card,
–UCH,
–optical presence sensors located in the door handles,
–access aerials integrated in the door handles and the tailgate, *
–the locking switches incorporated in the door handles,
–opening element locking motors.
b/ Hands-free unlocking:
When a hand is detected inside a handle (interruption of one of the optical beams) or a press on the boot opening
switch is detected, the UCH sends a 125 kHz signal to the access aerials and interrogates the access zone (driver-
side aerial interrogated first). If the Renault card is in the access zone, it responds to the UCH at 433 MHz. If the
UCH authenticates the Renault card, it requests unlocking of the opening elements or boot-only locking motors.
Hands-free unlocking of the entire vehicle by stage:
1The user places his/her hand around one of the door handles and the optical sensor detects a presence.
2If the Renault card is not disabled in hands-free, the UCH sends a 125 kHz encrypted signal over the access
aerials (initial interrogation is of the aerials on the side of the handle activated).
3If the Renault card recognises the code, it responds to the UCH using a 433 MHz encrypted signal.
4The UCH confirms that the Renault card code is correct and activates the locking motors.
* (3 or 5 access aerials depending on the number of doors and the fabrication date of the vehicle)

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-13
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-13V9 MR-372-J84-87B000$086.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
Conditions required:
–Interruption of one of the optical beams in one of the handles or pressing the boot or rear screen opening switch.
–A vehicle card detected by the access aerials.
–No + after ignition feed on the vehicle.
–The card must not be hands-free disabled (a Renault card is disabled for hands-free starting and access if it was
present in the vehicle when it was locked; the card is no longer disabled if it is detected by any aerial during
unlocking).
Statuses available for the unlocking function:
The UCH receives the unlocking request when an optical beam is cut on one of the handles. The sensors' power
supply can be displayed using the ET054 Optical sensors supplied status.
Operation of the sensors can be viewed using statuses ET055 Driver's side front optical sensor, ET056 Driver's
side rear optical sensor, ET057 Passenger side front/rear optical sensors and boot switch status ET060 Tailgate
locking button. The status of the tailgate opening request is visible using status ET061 Tailgate opening request.
The status of the request to open the rear screen can be checked using status ET062 Rear screen opening request.
The power supply level on the vehicle can be viewed using ET014 Power supply level requested.
The AC037 Transmitting aerials fault finding command interrogates the aerials for an update of potential faults.
Commands AC032 Test driver's side external aerials, AC033 Test passenger side external aerials and AC034
Test boot external aerials are used to check each zone separately. When the card is in the interrogated zone, the
card reader flashes. The interrogation lasts 1 minute.
These commands are used to check the hands-free access zones around the vehicle and will operate even if the
hands-free card does not belong to the vehicle.
c/ Hands-free unlocking of the boot only:
When a press on the boot opening switch is detected, the UCH receives the signal requesting opening (ET061
Tailgate opening request). The UCH sends a 125 kHz signal to the access aerials.
If the Renault card is in the access zone (initial interrogation on the boot side, then interrogation of both sides of the
vehicle), it responds to the UCH at 433 MHz.
If the UCH authenticates the card, the UCH orders unlocking of the boot only.
d) Hands-free locking:
When a press on a door handle closing switch is detected, the UCH sends a 125 kHz signal to the access aerials. If
the Renault card is in the access zone, it responds to the UCH at 433 MHz. If the UCH authenticates the card (and if
the UCH cannot be detected in the hands-free starting zone), the UCH requests the locking motors to lock.
If, however, there is another card in the vehicle, locking will be possible, but the card left in the vehicle will
temporarily lose its hands-free access and hands-free starting functions until the next unlocking operation
(inhibition).

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-14
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-14V9 MR-372-J84-87B000$086.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
Conditions required:
–At least one vehicle card detected by the access aerials and not detected by the starting aerials.
–No doors open.
–No Renault card in the card reader.
–No + after ignition feed on the vehicle.
–The card must not be hands-free disabled (a Renault card is disabled for hands-free starting and access if it was
present in the vehicle when it was locked; the card is no longer disabled if it is detected by any aerial during
unlocking).
Statuses available for the locking function:
The UCH receives the locking request in the form of an earth, when one of the locking buttons on the door handles
or in the centre of the boot badge is pressed.
The locking requests can be viewed using statuses ET058 Driver's side handle locking switch, ET059
Passenger's side handle locking switch and ET060 Tailgate locking switch. The statuses of the doors detected
by the UCH as open or closed are displayed using statuses ET053 Driver's door, ET042 Passenger's door, ET051
Rear left-hand door, ET052 Rear right-hand door, ET050 Tailgate/boot and ET041 Opening rear screen (if fitted
to the vehicle).
The power supply level on the vehicle can be viewed using ET014 Power supply level requested.
The AC037 Transmitting aerials fault finding command interrogates the aerials for an update of potential faults.
Commands AC032 Test driver's side external aerials, AC033 Test passenger side external aerials and AC034
Test boot external aerials are used to check each zone separately. When the card is in the interrogated zone, the
card reader flashes. The interrogation lasts 1 minute.
These commands are used to check the hands-free access zones around the vehicle and will operate even if the
hands-free card does not belong to the vehicle.
e/ Display
Unlocking is indicated by 1 flash of the direction indicators.
Locking is indicated by 2 flashes of the direction indicators.Hands-free locking of the entire vehicle by stage:
1) The user presses one of the locking switches on the door handle or tailgate (located in the badge).
2) If the Renault card is not disabled for hands-free operation, the UCH sends a 125 kHz encrypted signal to
the access aerials (interrogation of the aerials on the side of the activated handle is performed first), and to
the starting aerials.
3) If the Renault card authenticates the code, it responds to the UCH using a 433 MHz encrypted signal.
4)If the UCH detects at least one Renault card in the access zone and this is authenticated (at least one Renault
card detected by the external aerials and not detected by the starting aerials; this is necessary to avoid the
vehicle being locked with the card inside), the UCH activates the locking motors.
5) If the UCH detects other cards inside the vehicle, it disables these cards for hands-free functions (access
and starting) until the next time the vehicle is unlocked.

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-23
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-23V9 MR-372-J84-87B000$086.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
1.2 SUB-FUNCTION: PROTECTION
1Steering column lock
2Injection computer
3Card reader
4Start button
5Starter aerials
6Renault Card
7Multiplex network
8Wire connection
The UCH shares control of the vehicle's immobiliser protection system with other computers.
De-protection of the vehicle is performed in three consecutive stages:
–a) Authentication of the card (hands-free or card reader).
–Unlocking of the steering column lock (to allow after ignition feed to be established).
–Unlocking the injection computer.
1.2.1 Authentication of the Renault card:
Authentication is performed differently depending on whether the vehicle is fitted with the hands-free option or not.
a) Authentication of the Renault card when the vehicle is fitted with the hands-free option:
When the user presses the start button, the UCH activates its starting aerials and authenticates a card in the
following way:
1/ The UCH activates its three starting aerials which generate a 125 kHz radio frequency signal. This signal is sent
to the Renault card.
2/ If the Renault card is located in the zone covered by the starting aerials and recognises its UCH, it responds
directly to the UCH with a 433 MHz signal giving its identifier.

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-24
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-24V9 MR-372-J84-87B000$086.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
3) The UCH decrypts the response and compares it with that stored in its memory. If the result is correct, it continues
the starting procedure. The aerials stop transmitting once the card is authenticated.
If no Renault card responds in hands-free mode, the UCH interrogates the card reader. If the Renault card is in the
card reader, authentication is via transponder.
The card reader must be used to start in hands-free mode in the following situations:
–flat card battery,
–vehicle in an area of frequency interference,
–boot open (indication on instrument panel).
The statuses and commands available on the card authentication function:
–ET035 Radio frequency signal received.
–ET070 Start button.
–ET046 Immobiliser.
–ET014 Power supply level requested.
–AC036 Internal aerial testing.
b) Authentication of the Renault card when the vehicle is not fitted with the hands-free option:
When the user presses the start button, the UCH authenticates the card in the card reader using the transponder
mode (short-range data exchange at 125 KHz). The transponder mode does not require a battery in the card.
1Wire connection
2Card reader
3Short range TRANSPONDER connection
4Renault Card
The statuses and commands available on the card authentication function:
–ET070 Start button
–ET046 Immobiliser
–ET014 Power supply level requested

PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-29
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - System operation
87B
87B-29V9 MR-372-J84-87B000$086.mif
UCH
Vdiag No.: 44, 48,
4C, 4D, 4F, 50
1.4.1.2 The UCH:
1.4.1.3 The optical presence sensors built into the door handles (hands-free vehicles):
The optical presence sensors inform the UCH of the hands-free unlocking request for the entire vehicle when the
infrared beam is cut in one of the handles (by a hand).
This presence detection starts the hands-free access procedure.
To limit battery use, the optical sensors are powered at 12 V only for 72 hours after the last change of vehicle
locked-unlocked status. After this period, the handle must be pulled to operate a switch* which "wakes up" the UCH
to resupply the optical sensors. In this case, pull the handle a second time to open the door once the card has been
authenticated.
The switch signal* is parallel to the optical sensor signal: activation of the optical sensor or the switch* earths the
signal going to the UCH. Although it is a switch*, the signal is not constant when pulling and holding the handle.
switch*: Switch.a) In hands-free mode, the UCH receives the unlocking request through the optical sensors, and the
locking request through the locking switches.
b) The UCH manages the exchanges with the Renault card.
In hands-free mode:
The UCH interrogates and authenticates the Renault card via the access aerials located in the door
handles and the tailgate, at a frequency of 125 KHz.
After authentication from the UCH, the Renault card responds directly to it at 433 MHz.
Outside hands-free mode:
The UCH receives the access requests coming from card presses at 433 MHz (315 MHz in Japan).
The 433 MHz reception aerial is incorporated in the UCH (except Scénic II fitted with the SSPP function).
The signals are encrypted.
c) The UCH activates the locking motors.
If the exchanges between the Renault card and the UCH are correct, the UCH activates the locking
motors.