RENAULT TWINGO 2009 2.G Engine And Peripherals Passenger Compartment Connection Unit OBD Workshop Manual

8Electrical equipment
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"The repair procedures given by the manufacturer in this document are based on the
technical specifications current when it was prepared.
The procedures may be modified as a result of changes introduced by the
manufacturer in the production of the various component units and accessories from
which his vehicles are constructed."
V5
All rights reserved by Renault s.a.s.
Edition Anglaise
Copying or translating, in part or in full, of this document or use of the service part
reference numbering system is forbidden without the prior written authority of
Renault s.a.s.
© Renault s.a.s. 2008
PASSENGER COMPARTMENT CONNECTION
UNIT
UCH
Vdiag No.: 44
Fault finding - Introduction 87B - 2
Fault finding - List and location of components 87B - 7
Fault finding - Operating diagram 87B - 8
Fault finding - Role of components 87B - 9
Fault finding - Replacement of components 87B - 13
Fault finding - Configurations and programming 87B - 14
Fault finding - Fault summary table 87B - 24
Fault finding - Interpretation of faults 87B - 25
Fault finding - Conformity check 87B - 68
Fault finding - Status summary table 87B - 84
Fault finding - Interpretation of statuses 87B - 86
Fault finding - Parameter summary table 87B - 144
Fault finding - Interpretation of parameters 87B - 145
Fault finding - Command summary table 87B - 151
Fault finding - Interpretation of commands 87B - 152
Fault finding - Customer complaints 87B - 164
Fault finding - Fault Finding Chart 87B - 167
Fault finding - Tests 87B - 177

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PASSENGER 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 manual):
–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. REMINDER
To run fault finding on the vehicle computers, switch on the ignition.
To cut off the + after ignition feed, proceed as follows:Vehicle(s): New Twingo
Function concerned: Passenger compartment
connection unitName of computer: UCH
Vdiag No.: 44
Special tooling required
Multimeter
Elé. 1681 Universal bornier
–Switch on the ignition with the key.
–Connect the diagnostic tool and perform the required operations.
–Switch off the ignition with the key.
–Disconnect the diagnostic tool.
–Switch off the ignition.
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Vdiag No.: 44PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Introduction87B
Faults
Faults are declared as either present or stored (depending on whether they appeared in a certain context and have
disappeared since, or whether they remain present but have not been diagnosed within the current context).
The present or stored status of faults should be taken into consideration when the diagnostic tool is used following
the + after ignition supply being switched on (without operating 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 electrical lines which correspond to the fault,
–the connectors for these lines (for oxidation, bent pins, etc.),
–the resistance of the component detected as faulty,
–the condition of the wires (melted or split insulation, wear).
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 dealt with by
Customer complaints.
A summary of the overall procedure to follow is provided on the following page in the
form of a flow chart.

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Vdiag No.: 44PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Introduction87B
4. FAULT FINDING PROCEDURE
Perform a pre-diagnostic on the
system
Print the system fault finding log
(available on CLIP and in the
Workshop Repair Manual or
Technical Note)
Connect CLIP
no
Dialogue with
computer?
yes
Read the faults
no
Faults
present
yes
Deal with present faults
Deal with stored faults
no
The cause is
still presentFault
solved
yes
See ALP no. 1
Conformity check
no
The cause is
still presentFault
solved
yes
Use fault finding charts
(ALPs)
no
The cause is
still presentFault
solved
yes
Contact the Techline with the
completed fault finding log

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Fault finding - Introduction87B
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.
Tactile 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 to another wire.
If a fault is detected, repair or replace the wiring harness.

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Fault finding - Introduction87B
5. FAULT FINDING LOG
You will always be asked for this log:
–when requesting technical assistance from the Techline,
–for approval requests when replacing parts for which approval is obligatory
–to be attached to monitored parts for which reimbursement is requested. The log is needed for warranty
reimbursement, and enables better analysis of the parts removed.
6. SAFETY ADVICE
Safety rules must be observed during any work on a component to prevent any damage or injury:
–check the battery voltage to avoid incorrect operation of computer functions,
–Use the proper tools. IMPORTANTIMPORTANT
Any fault on a complex system requires thorough fault finding with the appropriate tools. The
FAULT FINDING LOG, which should be completed during the procedure, enables you to keep
track of the procedure which is carried out. It is an essential document when consulting the
manufacturer.
IT IS THEREFORE ESSENTIAL THAT THE FAULT FINDING LOG IS FILLED OUT EVERY TIME IT IS
REQUESTED BY TECHLINE OR THE WARRANTY RETURNS DEPARTMENT

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ENGINE HARNESS
FRONT ENGINE WIRING & ADDITIONAL HEADLIGHTS
DOOR WIRING
CEILING WIRING
PASSENGER COMPARTMENT WIRING
REAR BUMPER WIRING
TAILGATE WIRING
1UCH
2Passenger Compartment Relay/Fuse Box
3Electric power-assisted steering.
4Transponder ring.
5Air conditioning panel.
6One touch window/anti-pinch module.
7Exterior temperature sensor.
8Rain/light sensor & interior temperature sensor.
9Anti-pinch/sunroof.
2ABS computer.
2Injection computer.
3Preheating unit.
4Sequential gearbox computer.
5Engine fuse and relay box.
6Alternator.
7
2
61
2
3
5
4
8
5
7
43
1
6
9
PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding
- List and location of components
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PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Operating diagram
1UCH.
2Air conditioning.
3Interior lighting.
4Exterior lighting, signals.
5One touch windows and electric sunroof.
6Alarm.
7Radiofrequency key.
8Starter.
9Opening elements.
10 Front/rear wipers, washers.
11 Alternator.
12 BSS* connection
*BSS: (see Role of components, Role of connection BSS).
1
8
3
2
11
10
9
7
6
5
4
12
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PASSENGER COMPARTMENT CONNECTION UNIT
Fault finding - Role of components
GENERAL OPERATION
The UCH is involved in the following five functions (shared between several computers):
–Access-security function
This function is divided into three sub-functions: Access, Protection and Starting (see 82D, Access - Safety).
–Air heating and manual air conditioning function
This function is divided into four sub-functions, which are: User selection, Heating, Cold loop and Passenger
compartment ventilation (see 61A, Heating and see 62C, Manual air conditioning).
In this function, the UCH manages the heated rear screen operation indicator lights, heating controls and air
conditioning activation requests, by sending requests to the engine management computer:
–In the case of a vehicle fitted with manual air conditioning, by pressing on the air conditioning button.
–In the case of a vehicle fitted with climate control, by request from the user or the climate control computer in
automatic mode.
–Wiping function
This function is divided into two sub-functions, which are: Wiper control and Wiper power (see 85A,
Wiping-washing).
–Lighting Function
This function is divided into two sub-functions, which are: Lighting control and Lighting power (see 80D, Lighting).
–Energy management function
Note: There is no UPC on this vehicle; this function is managed by the UCH.
The system is composed of the UCH which stores the programming for electrical energy management, the starter,
the battery, and the alternator controlled via a BSS connection.
The role of this system is:
●to ensure electrical energy is supplied to the vehicle whilst respecting the dynamic performance
constraints of the engine and transmission assembly,
●to control alternator loading* and load shedding** during engine management authorisation or variation of
the electrical load,
●to ensure the quality of the on board network voltage in terms of the voltage level and variation,
●to optimise the battery charge by applying a voltage to its terminals correlating to its initial charge status
(in sleep mode) and to its internal temperature,
●to inform the engine management about the mechanical power taken from the accessories pulley, the
alternator charge rate and the rotor excitation current value,
●to run fault finding on the charging circuit: “Battery” warning light display.
*loading: This operation consists of transferring control of the vehicle's electrical consumption from the battery
to the alternator.
**load shedding: This operation consists of involving the battery in the vehicle's general electric power balance.
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Fault finding - Role of components87B
–Energy management function
Role of BSS connection:
This bidirectional connection located between the UCH and the alternator circulates the following signals:
–Signals sent by the alternator: rotor current value, alternator charge value and electrical, thermal and
mechanical fault statuses.
–Signals sent by the UCH to the alternator: voltage setpoint, rail setpoint and rail inhibition.
Role of the DF terminal:
The signal circulating in the DF terminal is the alternator charge signal (displayed using PR073 "Alternator
charge signal") which is used to adapt the alternator supply to the demands of the electrical consumers
(such as the passenger compartment heating resistors, heated rear screen, etc.).
Depending on the battery charge status, the operating phase and the battery temperature, the UCH determines what
the voltage across the battery terminals should be.
When the battery charge drops, and PR076 Battery voltage after rest decreases, the UCH can temporarily
increase PR075 Alternator setpoint voltage by 1 V for a period of 15 minutes after switching on + after ignition
feed.
Before and during starting, PR075 Alternator setpoint voltage is fixed at 10.7 V.
A maximum of 30 seconds after the engine has started, the UCH sets PR075 Alternator setpoint voltage to the
optimum value calculated.
The injection computer can also control the alternator regulation voltage. The injection computer sends the
maximum authorised power delivered by the engine, to the UCH via the multiplex network. If this power supplied by
the engine is less than the power consumed by the alternator, the UCH reduces the PR075 Alternator setpoint
voltage.
The battery warning light will flash if a low battery charge is detected (no-load voltage less than 12.2 V: voltage
measured during technical use) for the first 12 miles (20 kms), then the warning light stops flashing. Also, the magic
eye of the battery (the hydrometer) is black.
–Access - Security function (see 82D, Access - Security, Role of components).
–Heating and manual air conditioning function (see 61A, Heating, Role of components and 62C, Manual air
conditioning, Role of components).
–Wiping function (see 85A, Washing wiping, Role of components).
–Lighting function (see 80D, Lighting, Role of components). Note:
At the time of user activation, if the mileage is less than 12 miles (20 kms) the charge status is used to display a
warning: this ensures that vehicles are delivered with correct batteries.