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 - 7
AIR CONDITIONING
Fault finding - Function architecture62A
V4
Air conditioning system design
The air conditioning system uses four computers. The four computers are connected by the multiplex system, except
in the case of manual air conditioning, where the connection between the air conditioning control panel and the UCH
is by normal wiring.
The air conditioning control panel interprets the driver's wishes and transmits them to the other computers; it also
manages the passenger compartment ventilation, air distribution, air mixing and air recirculation.
The UCH transmits the request to engage the air conditioning compressor to the injection and controls the operation
of the passenger compartment heating resistors (RCH).
The injection receives the refrigerant fluid pressure signal from the pressure sensor. The injection computer
authorises or inhibits the request to engage the compressor depending on how the vehicle is operating and transmits
the signal to the Protection and Switching Unit (UPC).
The role of the UPC is to manage the power section of the air conditioning system. It controls the engagement of the
compressor, the engine cooling fan units and the heated rear screen.
GLOSSARY
RCH = passenger compartment air heating resistors
AC control panelUCH
–interpretation of driver's
wishes
–passenger compartment
ventilation management
–air distribution management
–air mixing management–passenger compartment air
heating resistors operation
management
UPC
(Power and Switching Unit)Injection computer
–engine unit management
–
compressor control
–
heated rear screen control–air conditioning authorisation
Manual air conditioning
and
Climate controlAIR CONDITIONING
Fault finding - Function architecture
CLIM X84 1.1
Edition 2
MR-372-J84-62A000$030.mif
