62B-95
MR-413-X44-62B000$920_eng.mif
V1
CLIMATE CONTROL
Diagnostic - Fault finding chart
Vdiag No.: 44
62B
ALP 14 Noisy compressor
NOTESOnly deal with this customer complaint after a full check with the diagnostic tool
(fault reading and configuration checks).
WARNING
Check that the computers active in the AIR CONDITIONING function (Injection, UCH
and climate control) are correctly configured.
Note:
Before starting any work, check that the noise is indeed coming from the compressor.
Check that the compressor belt is in good condition and check its tension (for engines without automatic
tensioning) (see MR 411, Mechanical, 11A, Top and front of engine, Accessories belt: Removal - Refitting).
Check that the compressor is correctly fixed (see MR 411 Heating and air conditioning system, 62A,
Air conditioning, Compressor: Removal - Refitting).
Check the refrigerant fluid and look for any leaks. Significant loss of fluid causes the compressor to make noises.
(see Technical Note 6001A, Air conditioning, 62A, Air conditioning, Air conditioning: Check).
If the fault is still present, replace the air conditioning compressor (see MR 411, Mechanical, 62A,
Air conditioning, Compressor: Removal - Refitting).
AFTER REPAIRCarry out a complete check with the diagnostic tool.
62B-99
MR-413-X44-62B000$966_eng.mif
V1
CLIMATE CONTROL
Fault finding - Help
Vdiag No.: 44
62B
OPERATION OF THE ENGINE COOLING FAN ASSEMBLY AS A FUNCTION OF THE REFRIGERANT FLUID
PRESSURE AND VEHICLE SPEED
Relative pressure (bar)
GMV = 1 Low-speed engine cooling fan
GMV = 2 High-speed engine cooling fan
GMV = 0 Engine cooling fan stopped
The engine cooling fan assembly is not used for vehicle speeds in excess of 70 km/h, except in rare cases where
the refrigerant fluid pressure is greater than 23 bar despite the high speed (e.g. driving behind a lorry).
When the vehicle is stationary, the engine cooling fan is always used at low speed if the refrigerant fluid relative
pressure is below 19 bar, otherwise it is used at high speed.
While the vehicle is being driven, 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.27
23
19
11
1
0AIR CONDITIONING INHIBITION
GMV = 2
GMV = 2 GMV = 1 GMV = 0
GMV = 1 GMV = 0
GMV = 1 GMV = 0
AIR CONDITIONING INHIBITION
20 30 45 70Vehicle speed in mph
