13B-5V4 MR-372-J84-13B000$010.mif
DIESEL INJECTION
Fault finding – Introduction13B
DDCR INJECTION
Vdiag No.: 44, 48
4. FAULT FINDING PROCEDURE (continued)
Wiring check
Fault finding problems
Disconnecting the connectors and/or manipulating the wiring may temporarily clear the cause of a fault.
The electrical measurements of the voltage, resistance, and insulation are generally correct, especially if the fault is
not present when the measurements are being taken (stored fault).
Visual inspection
Look for damage under the bonnet and in the passenger compartment.
Carefully check the fuses, insulators and wiring harness routing.
Look for signs of oxidation.
Physical inspection
When handling the wiring, use the diagnostic tool to detect any change in the status of the fault from stored to
present.
Make sure that the connectors are firmly locked.
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 insulation). Check that the clips and the tabs are correctly 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, to + 12 V or with another wire.
If a fault is detected, repair or replace the wiring harness.
5. FAULT FINDING LOG
IMPORTANTIMPORTANT
Any fault on a complex system requires thorough fault finding with the appropriate tools.
The FAULT FINDING LOG, which should be completed during the procedure, enables you to
keep track of the procedure which is carried out. It is an essential document when consulting
the manufacturer.
IT IS THEREFORE COMPULSORY TO COMPLETE A FAULT FINDING LOG EVERY TIME A FAULT FINDING
PROCEDURE IS PERFORMED
