62B - 3
CLIMATE CONTROL
Fault finding – Introduction62B
V3 MR-372-J84-62B000$010.mif
Vdiag No.: 44
Faults:
Faults are declared as 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 supplied (without acting on the system components).
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 instructions in the Notes section.
If the fault is confirmed when the notes 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 faulty component,
–The condition of the wiring (insulation melted or cut, chafing, etc.).
Conformity check
The aim of the conformity check is to check statuses and parameters that do not produce a fault display on the
diagnostic tool when they are 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 repairs.
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.
Notes about the conformity check for the air conditioning system
All variables (statuses and parameters) and commands required for the air conditioning function are divided into four
sub-functions:
–the COLD LOOP sub-function, which groups together all the information required for producing cold air,
–the USER SELECTION sub-function, which groups together all the information relating to the user's requests
(buttons pressed, warning lights, etc.),
–the HEATING sub-function, which groups together all the information required for producing warm air,
–the PASSENGER COMPARTMENT VENTILATION sub-function, which groups together all the information
relating to ventilation, distribution and air distribution within the passenger compartment.
ACREG X84 1.1
Edition 2
62B - 8
CLIMATE CONTROL
Fault finding – System operation62B
V3 MR-372-J84-62B000$020.mif
Vdiag No.: 44
SUMMARY OF ITEMS CONTROLLED OR OPERATED BY THE CLIMATE CONTROL COMPUTER:
Ventilation and air conditioning unit
Passenger
compartment
blower
Vehicle multiplex
network
Passenger
compartment
blower power
moduleRecirculatio
n motorDistribution
motorMixing
motorInternal
temperature
sensor Solar sensor
Actuator control Sensor management
Climate control computer (control panel)
Climate control
management
(hot and cold)User requests
management
(buttons pressed) Button lighting
Key:
Wire connections =
Multiplex connections =
ACREG X84 1.1
Edition 2
62B-17
CLIMATE CONTROL
Fault finding – Interpretation of faults62B
V3 MR-372-J84-62B000$060.mif
Vdiag No.: 44
DF010
CONTINUED
With the climate control computer connector connected and the ignition on ("forced" + after ignition: see
Introduction) check that there is a 12 V supply on track 2 of the mixing motor connector. If the supply is not
present and if no faulty connections are detected during the continuity checks: contact your Techline.
With the connector disconnected, check the resistance value of the mixer motor by measuring between:
track 2 and track 1 of the mixing motor connector,
track 2 and track 3 of the mixing motor connector,
track 2 and track 4 of the mixing motor connector,
track 2 and track 6 of the mixing motor connector.
For the four checks, a value of 100 ΩΩ Ω Ω
± 5 ΩΩ Ω Ω
at 20˚C should be obtained. Replace the mixer motor if this is not
the case.
If the fault is still present with the mixing motor removed but electrically connected, carry out a motor command
using the temperature buttons on the control panel: switch the temperature setting to maximum hot position
"27˚" (a value of 100%) then switch the temperature setting to maximum cold position "15˚" (a value of 0%).
The motor should switch from one direction to the other.
If the connections checked previously are correct but the motor does not switch during the commands: replace
the mixing motor.
If the commands have been performed correctly, check that the mixing flap motor is not jammed by trying to
move the mechanism.
Repair if necessary.
If the fault is still present, replace the mixing motor.
AFTER REPAIRClear the fault memory.
Follow the instructions to confirm repair.
If the motor has been replaced, refer to the Configurations and Programming
section.
Deal with any other faults.
ACREG X84 1.1
Edition 2
62B-19
CLIMATE CONTROL
Fault finding – Interpretation of faults62B
V3 MR-372-J84-62B000$060.mif
Vdiag No.: 44
DF012
CONTINUED
With the connector disconnected, check the resistance value of the distribution motor by measuring between:
track 2 and track 1 of the distribution motor connector,
track 2 and track 3 of the distribution motor connector,
track 2 and track 4 of the distribution motor connector,
track 2 and track 6 of the distribution motor connector.
For the four checks, a value of 100 ΩΩ Ω Ω
± 5 ΩΩ Ω Ω
at20˚C should be obtained. Replace the distribution motor if this
is not the case.
If the fault is still present with the distribution motor dismantled and connected, carry out a motor command
using the distribution buttons on the control panel: switch the distribution to demisting position (value 100%)
then switch the distribution setting to air vent position (value 0%). The motor should switch from one direction
to the other.
If the connections checked previously are correct but the motor does not switch during the commands: replace
the distribution motor.
If the commands have been performed correctly, check that the distribution motor flap is not jammed by trying
to move the mechanism.
Repair if necessary.
If the fault is still present, replace the distribution motor.
AFTER REPAIRClear the fault memory.
Follow the instructions to confirm repair.
If the motor has been replaced, refer to the Configurations and Programming
section.
Deal with any other faults.
ACREG X84 1.1
Edition 2
62B-45
CLIMATE CONTROL
Fault finding – Fault Finding Chart62B
V3 MR-372-J84-62B000$110.mif
Vdiag No.: 44
ALP 2
CONTINUED
With the distribution motor removed, operate the distribution
flaps manually by turning the centre of the control from one limit
to the other (the limits are V shaped).
Does the flap cover the whole range of movement, without
any areas of resistance?
YES
Remove the footwell vent ducts (lower ducts) to check that the
lower flap control linkages are present and correctly fitted (they
are connected to the upper flaps). Also ensure that lower flaps
move when the distribution flap manual control is operated.
Do the footwell (lower) distribution flaps move when the
distribution flaps are controlled?
YES
If the fault is still present with the distribution motor dismantled
and connected, carry out a motor command using the distribution
buttons on the control panel: switch the distribution flap to
demisting position (value 100%) then switch the distribution
setting to air vent position (value 0%).
Is the distribution motor operating?
YES
Remove the dashboard and visually check that when the
distribution flaps are moved manually (by turning the centre of the
control), moving the control does in fact move the distribution
flaps.
Is there movement?
YES
End of fault finding procedure.
NO
NO
NO
NORemove the dashboard to check
that nothing is preventing the
flaps from moving. Repair
(remove any foreign bodies
which may be blocking the flaps
and grease the centre of the flap
control mechanism). Replace
the distribution - ventilation unit if
it is not possible to repair it.
If the mountings of the lower flap
control linkages are not
damaged: resecure the linkages
and grease them slightly. If a
repair is not possible or if the
mountings are damaged:
replace the distribution -
ventilation unit.
Apply the fault finding procedure
for fault DF012 Distribution
motor circuit.
Replace the distribution -
ventilation unit.
AFTER REPAIRPerform a complete check using the diagnostic tool.
ACREG X84 1.1
Edition 2
62B-54
CLIMATE CONTROL
Fault finding – Fault Finding Chart62B
V3 MR-372-J84-62B000$110.mif
Vdiag No.: 44
ALP 13 No control panel lighting
NOTESOnly refer to this customer complaint after a full check of the multiplex network
and the air conditioning with the fault finding tool.
Special notes:
With the ignition on, the control panel screen is permanently on but the panel buttons
only light up when the sidelights are switched on.
Note:
If the external temperature sensor is faulty, the climate control computer is
switched on 5 seconds after the ignition is switched on (this allows a fault to be
identified as fault finding cannot be performed on the external temperature sensor
by the UCH).
Is the fault common to other components (instrument panel,
multifunction display, electric window buttons, etc.)?
YES
Switch on the ignition and switch on the side lights to check
there is a 12 V supply on track 6 of the brown 12-track
connector (PPH2) of the Protection and Switching Unit.
Is there a 12 V supply?
YES
Check the connection and the condition of the connectors at the air conditioning control panel
output.
Repair if necessary.
Check the insulation, continuity and absence of interference resistance on the following
connection:
Air conditioning computer 12-track connector
track 9
Repair if necessary.Protection and Switching Unit brown 12-track
(PPH2) connector
track 6
NO
NOPerform fault finding on the
protection and switching unit.
AFTER REPAIRPerform a complete check using the diagnostic tool.
ACREG X84 1.1
Edition 2