62B-52
CLIMATE CONTROL
Fault finding – Fault Finding Chart62B
V3 MR-372-J84-62B000$110.mif
Vdiag No.: 44
ALP 11 Unpleasant odours in the passenger compartment
NOTESOnly consult this customer complaint after a complete check using the
diagnostic tool.
Check that the cabin filter is not blocked or damaged.
Replace it if necessary.
Is the fault still present?
YES
Check that the condensation drain ring (water from the
evaporator) is not obstructed (under the body).
Repair if necessary.
Is the fault still present?
YES
Check the sealing of the heating unit in relation to the engine
compartment:
–Foam seal on the heater matrix coolant pipes fitted and in
good condition.
–Rubber seal on the radiator tank fitted and in good condition
(seal under the bonnet separating the engine compartment
from the windscreen aperture).
–Drain valve on the radiator tank fitted and in good condition.
Repair if necessary.
Is the fault still present?
YES
Remove the cabin filter to apply air conditioning system
cleaner using an extension pipe on the evaporator.
Spray the entire contents of the aerosol.
Leave the product to work for 15 minutes.
NO
NO
NOEnd of fault finding procedure.
End of fault finding procedure.
End of fault finding procedure.
AFTER REPAIRPerform a complete check using the diagnostic tool.
ACREG X84 1.1
Edition 2
62B-56
CLIMATE CONTROL
Fault finding – Fault Finding Chart62B
V3 MR-372-J84-62B000$110.mif
Vdiag No.: 44
ALP 14 Air conditioning noises during operation
NOTESOnly deal with this customer complaint after a full check with the diagnostic tool
(fault reading and configuration checks).
Check that the computers involved in the air conditioning function (Injection, Protection and
Switching Unit, UCH and Air conditioning control panel) are correctly configured.
Reconfigure if necessary (see 62A, Air conditioning, Configurations and Configuration reading).
Check that:
–the compressor fitted to the vehicle corresponds correctly to the engine (see MR 370 Mechanical, 62A, Air
conditioning, Air conditioning: Parts and consumables for the repair).
Replace the compressor if necessary (see MR 370, Mechanical, 62A, Air conditioning, Compressor: Removal
- Refitting).
–the compressor is correctly fixed (see MR 370 Mechanical, 62A, Air conditioning, Compressor: Removal -
Refitting).
Check the condition of the compressor belt and check its tension. Replace the belt if necessary (see MR 370
Mechanical, 11A, Top and front of engine, Accessories belt: Removal - Refitting).
Check that the intermediate pipes, condenser and dehydrator reservoir are correctly fitted.
–Check the mountings and brackets of the components.
–Check the contact between and proximity of the components.
(see MR 370 Mechanical, 62A, Air conditioning, Air conditioning: List and location of components).
Check the correct operation of the cooling fan assembly or passenger compartment fan assembly and
condenser:
–check the electrical supply of the fan using parameters ET007 High speed fan assembly control, AC009 Low
speed fan assembly and AC010 High speed fan assembly (see 62A, Air conditioning, Conformity check,
Cold loop sub-function).
Check the quantity of refrigerant (see MR 370 Mechanical, 62A, Air conditioning, Air conditioning: Parts
and consumables for the repair).
If the quantity of refrigerant is:
–Greater than the manufacturer's information, recharge according to the manufacturer's values (see MR 370
Mechanical, 62A, Air conditioning: Draining - Filling).
–Less than the manufacturer's information, check for leaks (see MR 370 Mechanical, 62A, Air conditioning,
Refrigerant circuit: Check).
If the fault is still present, replace the compressor (see MR 370, Mechanical, 62A, Air conditioning,
Compressor: Removal - Refitting).
AFTER REPAIRPerform a complete check using the diagnostic tool.
ACREG X84 1.1
Edition 2
62B - 58
CLIMATE CONTROL
Fault finding – Help62B
V3 MR-372-J84-62B000$120.mif
Vdiag No.: 44
CLIMATE CONTROL
Fault finding – Help
MEASURING THE CONTROL VOLTAGE OF THE PASSENGER COMPARTMENT BLOWER
POWER MODULE
There are two ways to measure the control voltage of the passenger compartment blower power module:
1 / MEASURING USING
A MULTIMETER (in the voltmeter position, direct voltage measurement):
With the power module connector connected, measure across track 6 of the module and the earth.
At speed 0 the voltage measured is equal to the battery voltage (± 1 V) and at speed 8 the voltage is 5 V (± 0.5 V). The
voltage varies between 0 and 14 V for the seven intermediate speeds.
Examples of measurements taken with the voltmeter with the engine at idling speed (values given as a guide):
2 / MEASURING USING
AN OSCILLOSCOPE (Optima 5800, CLIP technique):
The blower power module is controlled by pulse width modulated control voltage (PWM).
This control voltage is always 12 V, it is the control signal (square signal) that varies:
the amplitude and frequency do not vary but instead the high status (12 V) varies in relation to the low status (5 V).
To take the measurement, connect the earth lead of the oscilloscope to the battery earth and the measuring lead of the
oscilloscope to track 6 (6-track connector) of the power module (module connector connected).
Adjust the time base on the oscilloscope to 500 µµ µ µ
s per division with a calibration of 5 V per division.
The signals obtained should be: a straight line at 14 V (± 1 V) for speed 0, and a straight line at 5 V (± 0.5 V) for speed 8.
Examples of measurements taken with the oscilloscope with the engine at idling speed (for information only):
* Passenger compartment blower PWM: passenger compartment blower pulse width modulation control voltage.
Passenger
compartment
blower speed012345678
Voltage
measurement13.77 V 12.26 V 11.79 V 11.22 V 10.43 V 9.44 V 8.08 V 6.66 V 4.96 V
PR019
Passenger
compartment
blower PWM
setting*0% 18% 23% 30% 39% 51% 66% 82% 100%
Passenger
compartment
blower speed012345678
Duration of high
status....... 450 µs400 µs350 µs300 µs250 µs200 µs150 µs.......
Duration of low
status....... 50 µs100 µs150 µs200 µs250 µs300 µs350 µs.......
PR019
Passenger
compartment
blower PWM
setting*0% 18% 23% 30% 39% 51% 66% 82% 100%
ACREG X84 1.1
Edition 2
MR-372-J84-62B000$120.mif
62B - 60
CLIMATE CONTROL
Fault finding – Help62B
V3 MR-372-J84-62B000$120.mif
Vdiag No.: 44
Operation of the engine cooling fan assembly according to the refrigerant fluid pressure
and vehicle speed.
GMV = 1 Engine cooling fan low speed
GMV = 2 Engine cooling fan high speed
GMV = 0 Engine cooling fan stopped
The engine cooling fan assembly is not used for vehicle speeds over 42 mph (70 km/h), except in rare cases where
the refrigerant fluid pressure is above 23 bar in spite of the speed (e.g.: driving behind a lorry).
When stationary, the engine cooling fan is used systematically at low speed if the refrigerant fluid relative pressure is
below 19 bar, at high speed in the opposite case.
While driving, the engine cooling fan may either not operate, or operate at low or high speed depending on the
refrigerant fluid pressure at the condenser outlet and the vehicle speed.Pressure (relative bar)
AIR CONDITIONING DEACTIVATION
GMV = 2
GMV = 2 GMV = 1 GMV = 0
GMV = 1 GMV = 0
GMV = 1 GMV = 0
AIR CONDITIONING DEACTIVATION
12 (20) 18 (30) 27 (45) 42 (70) Vehicle speed in
mph (km/h)
ACREG X84 1.1
Edition 2
