DiagnosticsDiagnostics
Diagnostics
HAZARDOUS APPROACH .
Replacing parts with the aim of discovering which component is faulty.
Asking a colleague what they usually do.
Not knowing what you are looking for .
Not using documentation .
Following the documentation without thinking and without trying to understand .
Not knowing how to correctly use the tools necessary for carrying out diagnostics.
Searching all the documentation for information.
Carrying out a series of unrelated checks
Carrying out checks on the vehicle following the wiring diagram from start to finish
Repairing the failure without knowing the cause
Diagnostics
Knowing exactly where to find the information in the documentation.
Locating the failure as closely as possible before starting the search .
Adopting a simple and consistent procedure.
Simplifying the wiring diagrams.
Searching for the cause of the failure .
Checking the system following repair.
Diagnostics
THE N.A.L.D.R.V. METHOD
NOTING THE SYMPTOMS
Confirm the customer complaint. Note the symptoms, what is not operating, but above all what is operating.
ANALYSING THE DATA
LOCATING THE FAILURE
Refine the search by cutting out everything that is operating from the procedure.
Simplify the search by determining and checking the most accessible points first.
Diagnostics
REPAIRING THE FAILURE
VERIFYING THE SYSTEM
Use the various checking procedures.
Diagnostics
SIDE
LIGHT
Diagnostics
Before operating on the vehicle
1) Analyse the sequence of repair (if necessary confirm the customer complaint)
2) Look for the service documentation relevant to the vehicle (Build Code, or Chassis No.) and the corresponding wiring diagrams
3) Define the area of the search from the documentation
Application of N.A.L.D.R.V.
NOTE THE SYMPTOMS
Diagnostics
Diagnostics
Right rear lights, left front lights, right front lights. Indicators
reversing lights, fog lamp and left brake light.
therefore:
Fuse Fl2 => OK
Fuse Fl3 => OK
List of possible causes
Continuity between F12 and terminal 5 (7-way white BFOO)
Wire V121- VO91 cut
Continuity between terminal 6 (10-way white) and terminal 2 (6-way white) right
Taillight Wire VO93
Continuity between terminal 5 (6-way brown) and terminal 1 (2-way white)
Diagnostics
Continuity between terminal 2 (2-way white) right taillight &right rear
Right taillight
Wire V295
Wire V296
LOCATE THE FAILURE
Amongst all the possible causes, look for those which are common
DETERMINE THE CAUSE
Examples:
1) If the cause of the failure is a cut wire, check that it was not cut by rubbing on a protruding panel
2) If the cause of the failure is a + 12V continuity problem on the right taillight printed circuit, check that there is no entry of water
Diagnostics
Diagnostics
Diagnostics