87G - 2
ENGINE COMPARTMENT CONNECTION UNIT
Fault finding - Introduction
87G
V6 MR-372-J84-87G000$066_eng.mif
187G
UPC
Vdiag No.: 44ENGINE 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 version.
Type of diagnostic tools
–CLIP
Special tooling required
3. RECAP
Procedure
To run diagnostics on the vehicle's computers, switch on the ignition in fault finding mode (forced + after ignition
feed).
Proceed as follows:
–insert the vehicle card in the card reader,
–press and hold Start button (longer than 5 seconds) with start conditions not fulfilled,
–connect the diagnostic tool and perform the desired operations.
To turn off the + APC feed proceed as follows:
–disconnect the diagnostic tool,
–press the Start button twice briefly (less than 3 seconds),
–check that the + APC has been turned off by the computer indicator lights on the instrument panel
being switched off. Vehicle(s): MEGANE II, SCENIC II
Function concerned: UPCName of computer: UPC
VDIAG No.: 44
Special tooling required
Multimeter
Universal bornier
Note:
The left-hand and right-hand xenon lamp computers are powered when the dipped beam headlights light up. It will
therefore not be possible to run fault finding on them until the ignition has been switched on in fault finding mode
(forced + APC) and the dipped beam headlights have been switched on.
MR-372-J84-87G000$066_eng.mif
87G - 5
ENGINE COMPARTMENT CONNECTION UNIT
Fault finding - Introduction
87G
V6 MR-372-J84-87G000$066_eng.mif
UPC
Vdiag No.: 44
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 protective parts, 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 tightened,
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 their 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.
Resistance check:
Check the continuity of entire lines, then section by section.
Look for a short circuit to earth, the +12 V feed or with another wire.
If a fault is detected, repair or replace the wiring harness.
