ENGINE COMPARTMENT CONNECTION UNIT
Fault finding - System operation87G
87G-11V7 MR-372-J84-87G050$110.mif
UPC
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 - System operation87G
87G-12V7 MR-372-J84-87G050$110.mif
UPC
Vdiag No.: 48, 4C
9 - Injection
The Protection and Switching Unit is involved in injection operation, relating to supplying the computer and its
sensors.
Supply malfunctions may lead to engine management customer complaints (rough idle, etc.).
10 - Fuse fault finding
The Protection and Switching Unit can detect the condition of its fuses and indicate faults using:
DF014 LEFT-HAND SIDE LIGHT CIRCUIT.
DF015 RIGHT-HAND SIDE LIGHT CIRCUIT.
DF016 LEFT-HAND DIPPED HEADLIGHT CIRCUIT.
DF017 RIGHT-HAND DIPPED HEADLIGHT CIRCUIT.
DF018 LEFT-HAND MAIN BEAM HEADLIGHT CIRCUIT.
DF019 RIGHT-HAND MAIN BEAM HEADLIGHT CIRCUIT.
DF020 FRONT FOG LIGHT CIRCUIT.
DF021 REVERSING LIGHT(S) CIRCUIT.
DF022 REAR SCREEN DE-ICER CIRCUIT.
DF023 FRONT WINDSCREEN WIPER CIRCUIT.
DF024 GAS COMPUTER SUPPLY.
DF025 AIRBAG/ELECTRIC POWER-ASSISTED STEERING SUPPLY.
DF026 AUTOMATIC TRANSMISSION SUPPLY.
DF029 STEERING COLUMN LOC/ENGINE MANAGEMENT SUPPLY.
DF030 AIR CONDITIONING COMPRESSOR SUPPLY CIRCUIT.
DF031 HEADLIGHT WASHERS SUPPLY CIRCUIT.
DF032 + 12 V RELAY SUPPLY CIRCUIT.
DF036 STEERING COLUMN LOCK SUPPLY CIRCUIT.
To carry out fault finding on the fuses, run command AC016 Test electrical supply circuits.
If a fuse is faulty, the associated fault becomes STORED.
Once the fuse has been replaced or the repair completed, run command AC016 Test electrical supply circuits
again to clear the fault.
Protection and Switching Unit Version
There are 4 Protection and Switching Unit versions:
–N1: vehicle with a 340 W fan assembly.
–N2: vehicle with a 460 W fan assembly.
–N3: vehicle with a 550 W fan assembly (external relay).
–N4: vehicle with 340 W, 460 W or 550 W fan assemblies + automatic transmission and/or LPG and/or with
headlight washers.
ENGINE COMPARTMENT CONNECTION UNIT
Fault finding - Configurations and programming87G
87G-14V7 MR-372-J84-87G050$220.mif
UPC
Vdiag No.: 48, 4CENGINE COMPARTMENT CONNECTION UNIT
Fault finding - Configurations and programming
This operation is used to configure the Protection and Switching Unit to the equipment present in the vehicle.
Procedure to follow for modifying these configurations:
●Establish dialogue with the UPC.
●Select the repair mode menu.
●Select the configure menu.
●Select line VP004 Vehicle parameters.
●Select the line corresponding to the vehicle equipment from the drop-down menus.
●Confirm the configurations selected and then click on validate.
●Switch the ignition off and then back on for the configurations to be recognised by the computer.
●In the configuration reading menu, check that each configuration has been performed.
Make sure that all the vehicle's equipment is working.Equipment required
CLIP diagnostic tool
Configuration Configuration reading Name of configuration
Automatic
(the alternator is
automatically recognised
by the Protection and
Switching Unit)LC001 Type of alternator
VP004 LC008 Gearbox type
VP004 LC007 Front fog lights
VP004 LC013 Headlight washers
MR-372-J84-87G050$220.mif
ENGINE COMPARTMENT CONNECTION UNIT
87G
87G - 15V7 MR-372-J84-87G050$275.mif
UPC
Vdiag No.: 48, 4CENGINE COMPARTMENT CONNECTION UNIT
Fault finding - Fault summary table
Summary of faults on which fault finding can be performed by the Protection and Switching Unit.
(With corresponding design office codes).
Tool fault Associated DTC Diagnostic tool title
DF006 920E COMPUTER
DF007 9211 UPC - ALTERNATOR CONNECTION
DF009 9214 + AFTER IGNITION FEED CIRCUIT (Vdiag 4C only)
DF012 9210 ALTERNATOR
DF013 920F VOLTAGE REGULATION
DF014 9217 LEFT-HAND SIDE LIGHT CIRCUIT
DF015 9218 RIGHT-HAND SIDE LIGHT CIRCUIT
DF016 9215 LEFT-HAND DIPPED HEADLIGHT CIRCUIT
DF017 9216 RIGHT-HAND DIPPED HEADLIGHT CIRCUIT
DF018 921B LEFT-HAND MAIN BEAM HEADLIGHT CIRCUIT
DF019 921C RIGHT-HAND MAIN BEAM HEADLIGHT CIRCUIT
DF020 921D FRONT FOG LIGHT CIRCUIT
DF021 9226 REVERSING LIGHT(S) CIRCUIT
DF022 921E REAR SCREEN DE-ICER CIRCUIT
DF023 921A WINDSCREEN WIPER CIRCUIT
DF024 9222 GAS COMPUTER SUPPLY
DF025 9223 ELECTRIC POWER ASSISTED STEERING/AIRBAG
SUPPLY
DF026 9224 AUTOMATIC GEARBOX SUPPLY
DF027 9225 ACCESSORIES SUPPLY
DF029 9221 INJECTION/STEERING COLUMN LOCK SUPPLY
DF030 9219 CLIMATE CONTROL COMPRESSOR SUPPLY CIRCUIT
DF031 921F HEADLIGHT WASHER SUPPLY CIRCUIT
DF032 9227 +12 V RELAY SUPPLY CIRCUIT
DF033 9229 FAN ASSEMBLY SUPPLY CIRCUIT
DF034 9212 ALTERNATOR TYPE
DF035 9213 COMPUTER SUPPLY VOLTAGE
DF036 9220 STEERING COLUMN LOCK SUPPLY CIRCUIT
MR-372-J84-87G050$275.mif
ENGINE COMPARTMENT CONNECTION UNIT
Fault finding - Interpretation of faults87G
87G-23V7 MR-372-J84-87G050$330.mif
UPC
Vdiag No.: 4C
DF009
CONTINUED
Check the connection and condition of the passenger compartment fuse and relay box, the gear lever display,
the steering column top control module, the additional heater relay 1 and 2, the diagnostic socket, the
parking distance control ECU, the right and left-hand rear electric window switch, the radio, the electric
door mirror control, the front and rear electric window locking controls and the passenger electric window
switch, component codes 260, 1129, 1546, 1067, 1068, 225, 1222, 130, 131, 261, 134, 135, 1511, 1512
and 133.
Check for a voltage on connection AP43 to the connectors for the passenger compartment fuse and relay box,
the gear lever display, the steering column top control module, the additional heater relay 1 and 2, the
diagnostic socket, the parking distance control ECU, the right and left-hand rear electric window switch,
the radio, the electric door mirror control, the front and rear electric window locking controls, the
passenger electric window switch, component codes 260, 1129, 1546, 1067, 1068, 225, 1222, 130, 131, 261,
134, 135, 1511, 1512 and 133.
If the connection or connections are faulty and if there is a repair procedure (see Technical Note 6015A, Electrical
wiring repair, Wiring: Precautions for repair), repair the wiring, otherwise replace it.
Check the insulation, continuity and the absence of interference resistance on the following connections:
–AP31 between components 1337 and 997,
–AP11 between components 1337, 485, 155 and 1109,
–APCB between components 1337 and 645,
–AP15 between components 1337 and 1088,
–AP44 between components 1337, 756 and 1232,
–AP43 between components 1337, 260, 1129, 1546, 1067, 1068, 225, 1222, 130, 131, 261, 134, 135, 1511, 1512
and 133.
If the connections are faulty and if there is a repair procedure (see Technical Note 6015A, Electrical wiring
repair, Wiring: Precautions for repair), repair the wiring, otherwise replace it.
Check the connection and condition of the Protection and Switching Unit, component code 1337.
If the connector is faulty and if there is a repair procedure (see Technical Note 6015A, Electrical wiring repair,
Wiring: Precautions for repair), repair the connector, otherwise replace the connector.
If the fault is still present, contact the Techline.
AFTER REPAIRErase the faults from the computer memory, switch the + after ignition supply off and
back on again and run another check using the diagnostic tool.
ENGINE COMPARTMENT CONNECTION UNIT
Fault finding - Interpretation of faults87G
87G-26V7 MR-372-J84-87G050$330.mif
UPC
Vdiag No.: 48, 4C
DF014
PRESENT
OR
STOREDLEFT-HAND SIDE LIGHT CIRCUIT
CO: Open circuit
CC.0: Short circuit to earth
CO
NOTESSpecial note:
To display this fault as present or stored, run the command
AC016 Electrical supply circuit test.
Use Wiring Diagrams Technical Note for Mégane II or
Scénic II.
Check that the front left-hand side light bulb is sound.
Repair if necessary.
Check the condition and connection of the connector to the left-hand headlight, component code 227 (tabs bent,
broken, oxidised).
If the connector is faulty and if there is a repair procedure (see Technical Note 6015A, Electrical wiring repair,
Wiring: Precautions for repair), repair the connector, otherwise replace the connector.
Check that the earth connection code MAS, for the left-hand headlight connector is perfect.
If the connection is faulty and if there is a repair procedure (see Technical Note 6015A, Electrical wiring repair,
Wiring: Precautions for repair), repair the wiring otherwise replace the wiring.
Check the condition and connection of the Protection and Switching Unit 8-track connector AN (tabs broken, bent
or oxidised).
If the connector is faulty and if there is a repair procedure (see Technical Note 6015A, Electrical wiring repair,
Wiring: Precautions for repair), repair the connector, otherwise replace the connector.
Check the insulation, continuity and the absence of interference resistance on the following connection:
–LPG between components 1337 and 227.
If the connection is faulty and if there is a repair procedure (see Technical Note 6015A, Electrical wiring repair,
Wiring: Precautions for repair), repair the wiring otherwise replace the wiring.
Check the fitting and switch on the left-hand headlight.
Repair if necessary or replace the light if it is faulty.
If the fault is still present, contact the Techline.
AFTER REPAIRRun command AC016 "Electrical supply circuits test".
Erase the faults from the computer memory, switch the + after ignition supply off and
back on again and run another check using the diagnostic tool.
USM_V48_DF014/USM_V4C_DF014
ENGINE COMPARTMENT CONNECTION UNIT
Fault finding - Interpretation of faults87G
87G-28V7 MR-372-J84-87G050$330.mif
UPC
Vdiag No.: 48, 4C
DF015
PRESENT
OR
STOREDRIGHT-HAND SIDE LIGHT CIRCUIT
CO: Open circuit
CC.0: Short circuit to earth
CO
NOTESSpecial note:
To display this fault as present or stored, run the command
AC016 Electrical supply circuit test.
Use Wiring Diagrams Technical Note for Mégane II or
Scénic II.
Check that the front right-hand side light bulb is sound.
Repair if necessary.
Check the condition and connection of the right-hand headlight, component code 226 (tabs broken, bent or
oxidised).
If the connector is faulty and if there is a repair procedure (see Technical Note 6015A, Electrical wiring repair,
Wiring: Precautions for repair), repair the connector, otherwise replace the connector.
Check that the earth connection code MAS for the right-hand headlight connector, component code 226 is
perfect.
If the connection is faulty and if there is a repair procedure (see Technical Note 6015A, Electrical wiring repair,
Wiring: Precautions for repair), repair the wiring otherwise replace the wiring.
Check the condition and connection of the Protection and Switching Unit 8-track AN connector, component code
1337 (tabs broken, bent or oxidised).
If the connector is faulty and if there is a repair procedure (see Technical Note 6015A, Electrical wiring repair,
Wiring: Precautions for repair), repair the connector, otherwise replace the connector.
Check the insulation, continuity and the absence of interference resistance on the following connection:
–LPD, between components 1337 and 226.
If the connection is faulty and if there is a repair procedure (see Technical Note 6015A, Electrical wiring repair,
Wiring: Precautions for repair), repair the wiring otherwise replace the wiring.
Check the fitting and switch on the right-hand headlight.
Repair if necessary or replace the light if it is faulty.
If the fault is still present, contact the Techline.
AFTER REPAIRRun command AC016 "Electrical supply circuits test".
Erase the faults from the computer memory, switch the + after ignition supply off and
back on again and run another check using the diagnostic tool.
USM_V48_DF015/USM_V4C_DF015
ENGINE COMPARTMENT CONNECTION UNIT
Fault finding - Interpretation of faults87G
87G-38V7 MR-372-J84-87G050$330.mif
UPC
Vdiag No.: 48, 4C
DF020
PRESENT
OR
STOREDFRONT FOG LIGHT CIRCUIT
CO: Open circuit
CC.0: Short circuit to earth
CO
NOTESSpecial note:
To display this fault as present or stored, run the command
AC016 Electrical supply circuit test.
Use Wiring Diagrams Technical Note for Mégane II or
Scénic II.
Check that the front fog light bulbs are sound.
Repair if necessary.
Check the condition and connection of the 2-track connectors for the front fog lights, component code 176 and
177 (tabs broken, bent or oxidised).
If the connector is faulty and if there is a repair procedure (see Technical Note 6015A, Electrical wiring repair,
Wiring: Precautions for repair), repair the connector, otherwise replace the connector.
Check that the earth on connection code MAS for the front right-hand fog light, component code 176 is perfect.
If the connection is faulty and if there is a repair procedure (see Technical Note 6015A, Electrical wiring repair,
Wiring: Precautions for repair), repair the wiring otherwise replace the wiring.
Check that the earth on connection code MAS for the front left-hand fog light, component code 177 is perfect.
If the connection is faulty and if there is a repair procedure (see Technical Note 6015A, Electrical wiring repair,
Wiring: Precautions for repair), repair the wiring otherwise replace the wiring.
Check the condition and connection of the 8-track connector AN for the Protection and Switching Unit,
component code 1337 (tabs bent, broken, oxidised).
If the connector is faulty and if there is a repair procedure (see Technical Note 6015A, Electrical wiring repair,
Wiring: Precautions for repair), repair the connector, otherwise replace the connector.
Check the insulation, continuity and the absence of interference resistance on the following connections:
–8E between components 1337 and 177,
–8F between components 1337 and 176.
If the connection or connections are faulty and if there is a repair procedure (see Technical Note 6015A, Electrical
wiring repair, Wiring: Precautions for repair), repair the wiring, otherwise replace it.
Check the fitting and switch for the front fog lights.
Repair if necessary or replace the light(s) if faulty.
If the fault is still present, contact the Techline.
AFTER REPAIRRun command AC016 "Electrical supply circuits test".
Erase the faults from the computer memory, switch the + after ignition supply off and
back on again and run another check using the diagnostic tool.
USM_V48_DF020/USM_V4C_DF020