engine oil RENAULT SCENIC 2008 J84 / 2.G Engine Compartment Connection Unit Workshop Manual

ENGINE COMPARTMENT CONNECTION UNIT
Fault finding - System operation87G
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Vdiag No.: 48, 4CENGINE COMPARTMENT CONNECTION UNIT
Fault finding - System operation
General operation
The Protection and Switching Unit is involved in the following functions:
–Access - Safety.
–Air conditioning.
–Lighting.
–Wipers.
–Charging circuit.
–Oil pressure detection.
–Electric power distribution.
1 - Electric power distribution
The main function of the Protection and Switching Unit is to switch and distribute the power supply to the vehicle's
systems, actuators or computers.
Part of this function is handled within the unit, but it is not electronically controlled by the computer.
+ 12 V battery feed
The Protection and Switching Unit receives energy from the battery via the Busbar and MM connectors (tracks 6 and
4) and redistributes the + 12 V feed.
+ 12 V after ignition
The UCH sends the Protection and Switching Unit the + 12 V after ignition feed request via the multiplex network.
When the Protection and Switching Unit receives this request, it actuates the after ignition relay unconditionally. The
signal is distributed to the sensors, actuators and computers.
2 - Charge circuit
One of the main functions of the Protection and Switching Unit is managing the charge circuit.
Purpose and components:
The main function of the charging circuit is to produce and distribute the electrical energy required to operate the
various electrical consumers on the vehicle (computers, lights, etc.).
It is also used to start the engine.
The main components are a battery, an alternator and a starter motor.
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ENGINE COMPARTMENT CONNECTION UNIT
Fault finding - System operation87G
87G-11V7 MR-372-J84-87G050$110.mif
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Vdiag No.: 48, 4C
5 - Exterior lighting
The Protection and Switching Unit receives lighting requests from the UCH via the multiplex network.
The computer then switches the power relays:
–side lights,
–dipped headlights,
–main beam headlights,
–front fog light.
For the operation of this function and the role of the Protection and Switching Unit in the control of this function,
(see 80D, Lighting).
6 - Wiping - Washing
The Protection and Switching Unit receives wiping requests from the UCH via the multiplex network.
The computer then switches the power relays:
–low or high-speed windscreen wiper,
–headlight washers pump relay.
–The Protection and Switching Unit also receives the windscreen wiper park position signal. Using this signal the
computer can determine whether the blade is jammed, and decide whether to stop the wiper motor to protect it.
For the operation of this function and the role of the Protection and Switching Unit in the control of this function,
(see 85A, W ipers-Washing).
7 - Oil pressure detection
The Protection and Switching Unit receives the oil pressure sensor signal and distributes it over the multiplex
network.
8 - Reverse gear engaged signal
The Protection and Switching Unit receives the reverse gear engaged position sensor signal and distributes it over
the multiplex network.

ENGINE COMPARTMENT CONNECTION UNIT
Fault finding - Conformity check87G
87G-56V7 MR-372-J84-87G050$440.mif
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Vdiag No.: 48, 4CENGINE COMPARTMENT CONNECTION UNIT
Fault finding - Conformity check
MAIN SCREEN
NOTESOnly carry out this conformity check after a complete check with the diagnostic tool
(fault reading and configuration checks).
Application conditions: engine stopped, + after ignition feed on.
FunctionParameter or Status
Check or ActionDisplay and Notes Fault finding
Battery voltagePR004:Battery voltage11 V < X < 13.5 V
(engine running:
X < 15.8 V)If there is a fault, refer to the
interpretation of parameter PR004.
Reverse gearET004:Reverse gear
engagedYES
NOIn the event of a fault, refer to the
interpretation of status ET004.
Oil pressureET027:Oil pressure
contactOPEN
CLOSEDNone.
+ 12 V after
ignition feedET003:+ 12 V after
ignition feed relay
controlINACTIVE
ACTIVENone.
StartingET062:UCH request to
injection or
Protection and
Switching UnitENGINE OFF
INACTIVE
+ APC
STARTINGIn the event of a fault, consult the
interpretation of status ET062.
USM_V48_CCONF/ USM_V4C_CCONF
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ENGINE COMPARTMENT CONNECTION UNIT
Fault finding - Status summary table87G
87G-64V7 MR-372-J84-87G050$495.mif
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Vdiag No.: 48, 4CENGINE COMPARTMENT CONNECTION UNIT
Fault finding - Status summary table
Tool status Diagnostic tool title
ET002Windscreen wiper protection
ET003+ 12 V after ignition feed relay control
ET004Reverse gear engaged
ET005Manual gearbox lever position
ET010Starting conditions met
ET013High-speed engine fan assembly relay control
ET014Low-speed engine fan assembly relay control
ET018Windscreen wiper park position
ET023Alternator thermal fault
ET027Oil pressure contact
ET062UCH request to injection or Protection and Switching Unit
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