86C -3V1 MR-413-X44-86C000$010.mif
MULTIMEDIA CONNECTION
Fault finding – Introduction86C
CBOX
Vdiag No.: 04
To cut off the + after ignition feed, proceed as follows:
Faults
Faults are declared either present or stored (depending on whether they appeared in a certain context and have
disappeared since, or whether they remain present but have not been diagnosed within the current context).
The present or stored status of faults should be taken into consideration when the diagnostic tool is used after the
+ after ignition feed has been activated (without any of the system components being activated).
For a present fault, apply the procedure described in the Interpretation of faults section.
For a stored fault, note the faults displayed and apply the Notes section.
If the fault is confirmed when the instructions are applied, the fault is present. Deal with the fault.
If the fault is not confirmed, check:
–the electrical lines which correspond to the fault,
–the connectors on these lines (corrosion, bent pins, etc.),
–the resistance of the component detected as faulty,
–the condition of the wires (melted or split insulation, wear).
Conformity check
The aim of the conformity check is to check the data that does not display a fault on the diagnostic tool when the
data is inconsistent. Therefore, this stage is used to:
–carry out fault finding on faults that do not have a fault display, and which may correspond to a customer complaint.
–check that the system is operating correctly and that there is no risk of a fault recurring after repair.
This section gives the fault finding procedures for statuses and parameters and the conditions for checking them.
If a status is not behaving normally or a parameter is outside the permitted tolerance values, consult the
corresponding fault finding page.
Customer complaints - Fault finding chart
If the test with the diagnostic tool is OK but the customer complaint is still present, the fault should be processed by
customer complaints. For vehicles with radio frequency remote control/key, use the key to switch off the ignition.
For vehicles with Renault cards,
Press the Start button twice briefly (less than 3 seconds),
Ensure that the forced + after ignition feed has been cut off by checking that the computer warning lights on the
instrument panel have gone out.
A synopsis of the general procedure to follow is provided on the following page in the form of a flow chart.
86C -5V1 MR-413-X44-86C000$010.mif
MULTIMEDIA CONNECTION
Fault finding – Introduction86C
CBOX
Vdiag No.: 04
4. FAULT FINDING PROCEDURE (continued)
4.1. Wiring check
Fault finding problems
Disconnecting the connectors and/or manipulating the wiring 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 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 properly 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.
Checking earth insulation
This check is carried out by measuring the voltage (multimeter in voltmeter mode) between the suspect connection
and the 12 V or 5 V. The correct measured value is 0 V.
Checking insulation against + 12 V or + 5 V
This check is carried out by measuring the voltage (multimeter in voltmeter mode) between the suspect connection
and the earth. In the first instance, the earth may be taken on the chassis. The correct measured value should be 0 V
Continuity check
A continuity check is carried out by measuring the resistance (multimeter in ohmmeter mode), with the connectors
disconnected at both ends. The expected result must be between: 0 ΩΩ Ω Ω
< X < 2 Ω for every connection. The line must
be fully checked, and the intermediate connections are only included in the method if this saves time during the fault
finding procedure. The continuity check on the multiplex lines must be carried out on both wires. The measured
value must be between: 0 ΩΩ Ω Ω
< X < 2 ΩΩ Ω Ω
.
Checking the supply
This check may be carried out using a test light (21 W or 5 W depending on the maximum authorised load)
