62A - 3
AIR CONDITIONING
Fault finding - Introduction62A
V4
Manual air conditioning
and
Climate control162AAIR CONDITIONING
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 and the Technical Notes for the injection fitted to the
vehicle, the UCH and the Protection and Switching Unit:
–Assisted fault finding (integrated into the diagnostic tool), Dialogys.
Wiring Diagrams:
–Visu-Schéma (CD-ROM), paper version.
Type of diagnostic tools
–CLIP
Special tooling required
3. RECAP
Procedure
To run fault finding on the vehicle's computers, switch on the ignition in fault finding mode (forced + after ignition
feed).
Proceed as follows:
–Renault card in the card reader (keyless vehicle scenario 1, entry level, not hands-free and scenario 2, top of the
range, hands-free)
–press and hold the Start button (longer than 5 seconds) with start-up conditions not fulfilled,
–connect the diagnostic tool and perform the desired operations.
To cut off + after ignition feed, proceed as follows:
–disconnect the diagnostic tool,
–press the Start button twice briefly (less than 3 seconds),
–check that the + after ignition feed has been cut off by checking that the computer warning lights on the instrument
panel have gone out. Vehicle: Scenic II
Function concerned: air conditioning
SPECIAL TOOLING REQUIRED
Multimeter
Elé. 1681Universal bornier
Note:
The left-hand and right-hand xenon bulb computers are powered when the dipped beam headlights light up. Fault
finding procedures can only be carried out on them after the ignition has been switched on in fault finding mode
(forced + after ignition feed) and the dipped headlights are on.
CLIM X84 1.1
Edition 2
MR-372-J84-62A000$020.mif
62A - 8
AIR CONDITIONING
Fault finding - Mode of operation62A
V4MR-372-J84-62A000$010.mif
Manual air conditioning
and
Climate controlAIR CONDITIONING
Fault finding - Mode of operation
General operation
The air conditioning system is composed of four sub-functions: heating, cold loop, passenger compartment
ventilation and user selection. Fault finding on the climate control is performed in two different ways using the
diagnostic tool.
The first procedure is by computer fault finding which makes it possible to communicate with just one computer
(select the computer concerned). The second procedure consists of performing fault finding by function which
allows communications to be established with all four computers of the AIR CONDITIONING function.
Description of the subsystems
Heating subsystem: this subsystem includes everything relating to the production of warm air in the vehicle and
management of the heated rear screen.
The main computers involved are the climate control computer (air mixing and blown air setpoint) and the UCH
(control and management of the passenger compartment heating resistors). The Protection and Switching Unit
controls the heated rear screen (and heated door mirror). The injection computer is only included in this subsystem
to supply the signals required for its management.
Cold loop subsystem: this subsystem includes everything involved in the vehicle's production of cold air.
The computers concerned are the climate control computer for air mixing, the injection computer to authorise
compressor engagement and the UPC to control the compressor and the engine fan units. On climate control
systems, the UCH merely transmits the request to engage the compressor from the climate control computer to the
injection computer.
On manual air conditioning systems, the UCH authorises or inhibits transmission of the request to engage the
compressor from the climate control computer to the injection computer depending on the status of the passenger
compartment blower (with manual air conditioning, the UCH receives and manages the passenger compartment
blower speed signal: compressor engagement is inhibited if the fan is not running).
User selection subsystem: this subsystem includes everything used to transmit the user's requests (pressing
buttons). The computers concerned are the climate control computer for climate control systems and the UCH. The
two other computers are not used for manual air conditioning.
Passenger compartment ventilation subsystem (climate control systems only): this subsystem includes
everything involved in ventilation, air mixing, air recirculation and air distribution. Therefore, only the climate control
computer is involved.
CLIM X84 1.1
Edition 2
MR-372-J84-62A000$040.mif
