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Diagnostic - Fault finding chart62B
ALP 4 Inefficient windscreen demisting
NOTESOnly consult this customer complaint after a complete check with the diagnostic
tool.
Special notes:
Check that the inside of the windows are not greasy, as this lowers the efficiency of
the demister.
Use the diagnostic tool to check that the computer is correctly configured by reading the LC046
GEOGRAPHICAL ZONE configuration. If necessary, reconfigure the computer (CF024 GEOGRAPHICAL
ZONE) and check that the windscreen demisting operates correctly.
Check that the air extraction vents are not blocked.
Repair if necessary.
Is the fault still present?
YES
Check that there is no water leakage in the
passenger compartment which would significantly
increase the humidity and reduce the efficiency of
the demisting. Repair if necessary (see ALP12
Water in the passenger compartment).
Is the fault still present?
YES
Check that the compressor operates correctly by switching on the air conditioning (press the “AC” button).
Repair if necessary (see ALP8 NO COLD AIR).
Check that the condensation (water from the evaporator) evacuation ring is not obstructed (under the vehicle).
Repair if necessary.
NO
End of fault finding procedure.
NO End of fault finding procedure.
AFTER REPAIRCarry out a complete check with the diagnostic tool.
CLIM_V44_ALP4
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ALP 5 No passenger compartment ventilation
NOTESOnly consult this customer complaint after a complete check with the diagnostic
tool.
Special notes:
The intermediate connector is located on the distribution-ventilation unit and the
passenger compartment blower unit control module is located slightly higher up,
below the heater matrix pipes.
Use the W iring Diagram Technical Note for the New Twingo.
Using the diagnostic tool, check that the passenger compartment
blower control setting given by the computer varies from 0 to 100 % by
checking parameter PR019 PASSENGER COMPARTMENT BLOWER
PWM SETTING (refer to the interpretation of this parameter).
Does the value vary?
Check that the control voltage (PWM) from the passenger compartment blower power module varies between 0
and 12 V (from 0 to 100 %) by measuring this voltage between connection 38LR of component 1023 and earth
MAN (connector disconnected).
Does the voltage vary correctly?
NOYES
Check the insulation and continuity of connection 38LR between components 419
and 1023.
If the connection is faulty (see Technical Note 6015A, Repairing electrical wiring,
Wiring: Precautions for the repair), repair the wiring, otherwise replace the wiring.
Before ignition feed, check for + 12 V accessories feed on connection SP3 of
component 1023 in relation to the chassis earth.
●Check the continuity of connection MAN between the intermediate connector and
component 1023.
●Check the continuity of connection MAN between the intermediate connector and
the chassis earth.
If the connection is faulty (see Technical Note 6015A, Repairing electrical wiring,
Wiring: Precautions for the repair), repair the wiring, otherwise replace the wiring.
If there is no +12 V accessories feed, check the condition and position of fuse F28 (30A)
in the passenger compartment fuse box. Consult section 81C Fuses.
If the checks do not reveal any faults, carry out conformity check on component 1016
and component 1428 if the vehicle is fitted with electric windows.
NOContact the
Techline.
AFTER REPAIRCarry out a complete check with the diagnostic tool.
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62B
CLIMATE CONTROL
Diagnostic - Fault finding chart
Preliminary cold loop efficiency test
ALP 8 No cold air
NOTESOnly deal with this customer complaint after a full check with the diagnostic tool
(fault reading and configuration checks).
Check that the engine speed is greater than 750 rpm and that the exterior
temperature is above 3 ˚C.
Check that the fuses are sound.
Use a multimeter and a 21 W test light.
Use the Wiring Diagram Technical Note, NEW TWINGO.
Engine running, air conditioning in maximum cold
position and maximum ventilation speed. After
10 minutes, is the high pressure pipe at the
compressor outlet hot, and the low pressure pipe at
the evaporator outlet cold and iced up?
NO
Check the cleanliness of the condenser. Touch the
pipes: are they warmer at the inlet than the outlet?
YES
Is the dehydrator reservoir pipe hot at the inlet and
outlet?
YES
Is the expansion valve pipe hot at the inlet and
outlet?
NO
Is the evaporator pipe hot at the inlet and outlet?
NO
1
YES2
NOReplace the condenser (see MR 411
Mechanical, 62A, Air conditioning,
Condenser: Removal - Refitting).
NOReplace the dehydrator reservoir
(see MR 411 Mechanical, 62A, Air
conditioning, Dehydrator reservoir:
Removal - Refitting).
YESReplace the expansion valve (see MR 411
Mechanical, 62A, Air conditioning,
Expansion valve: Removal - Refitting).
YESReplace the evaporator (see MR 411
Mechanical, 62A, Air conditioning,
Evaporator: Removal - Refitting).
AFTER REPAIRCarry out a complete check with the diagnostic tool.
Vdiag No.: 44
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Vdiag No.: 44CLIMATE CONTROL
Diagnostic - Fault finding chart62B
ALP 8
CONTINUED 1
1
Using the diagnostic tool statuses and parameters
screen (cold loop sub-function), check that the
temperature signals are consistent (no sensor
deviation resulting in incorrect measurement).
–Using parameters PR002
"exterior temperature", PR064
"coolant temperature" and PR001
"interior temperature".
Are the temperature signals consistent?
YES
Start the engine and switch on the air conditioning
by pressing the AC button (with a request for
maximum cold temperature and the passenger
compartment blower running).
Display the following status in the “User selection”
sub-function screen:
ET140 "air conditioning request" should be
ACTIVE and the “AC” symbol should be displayed
on the air conditioning control panel screen.
Is status ET140 ACTIVE?
YES
NOCarry out a conformity check:
–For the coolant temperature sensor,
see 13B, Diesel injection, Fault
summary table or 17B Petrol
injection, Fault summary table.
–For the exterior temperature sensor,
see 87B, Passenger compartment
connection unit, Fault summary
table.
–For the interior temperature sensor,
see 62B, Climate control, Fault
summary table.
Replace any faulty components.
NOAir conditioning request interpretation fault
on the climate control computer. Carry out
fault finding on the climate control
computer (see interpretation of
statuses).
AFTER REPAIRCarry out a complete check with the diagnostic tool.
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ALP 8
CONTINUED 2
With the engine running at idle speed, use the
diagnostic tool to check that the passenger
compartment central unit sends the start air
conditioning request to the injection computer.
Status ET030 Air conditioning request 2 should
display ACTIVE.
Is status ET030 "ACTIVE"?
YES
Using the diagnostic tool, display (injection cold
loop sub-function screen), the following statuses:
–ET004 Air conditioning authorised,
–ET088 Compressor activation request,
Is status ET004 "YES" and status ET088
"ACTIVE"
NO
Check that the injection computer is correctly configured. Status ET079 CLIMATE CONTROL PRESENT should
display YES (cold loop sub-function screen).
Is status ET079 YES?
YES
NOCheck that the UCH is correctly configured by
viewing the configuration reading LC013 Type
of air conditioning.
Should be “Climate control”
Reconfigure the UCH if necessary.
Check that the UCH is receiving the engine
operating status and passenger compartment
blower signals correctly (for manual air
conditioning). In the Cold Loop sub-function
screen, status ET142 "Engine operating
phase" should display “RUNNING” and status
ET015 "Passenger compartment blower"
should display “ACTIVE” and parameter
PR024 “Exterior temperature” is > 3˚C.
If the parameter and statuses are not correct,
carry out fault finding on the multiplex network
and UCH (interpretation of status ET015,
ET142 and parameter PR024).
YES
NO
Interpretation fault for status ET079, see
conformity check, cold loop sub-function:
–13B, Diesel injection,
–17B, Petrol injection.
AFTER REPAIRCarry out a complete check with the diagnostic tool.
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ALP 8
CONTINUED 3
Carry out fault finding on the injection system to ensure that no fault is present (if faults are displayed by the injection
computer, engagement of the air conditioning may be inhibited). If there are present or stored faults, carry out the necessary
repairs (see 13B, Diesel injection or 17B, Petrol injection).
Check that the refrigerant fluid pressure is correct (neither too low nor too high) using the PR037 Refrigerant fluid
pressure parameter (see Conformity check, Cold loop sub-function).
Check that the engine cooling fan assembly is at speed 1 by
viewing the following status on the cold loop sub-function
screen:
- Status ET022 Low-speed fan assembly request should
display ACTIVE.
Note:
These statuses are not displayed by all types of injection
(see Conformity check, Cold loop sub-function).
Does the engine cooling fan operate at low speed?
YES
NO
Using the diagnostic tool, run command
AC154 Low speed fan assembly relay.
Does the engine cooling fan operate at
low speed?
NO YES
Connector of component 321 disconnected. Connect a test
light between connection 49L of component 321 and the
chassis earth and run command AC154 Low speed fan
assembly relay.
Does the test light illuminate?
YES NO
Carry out fault finding
on the injection
system (sub-function:
cold loop and engine
cooling for low speed
fan assembly
activation).
Measure the resistance of component 321, between connections
49L and 49B of component 321. If the resistance measured is
infinite, replace the fan assembly resistor (component 321).D
AFTER REPAIRCarry out a complete check with the diagnostic tool.
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ALP 8
CONTINUED 5
Check the air conditioning compressor belt tension
(see Technical Note 3786A, Engine and
peripherals, 10A, Belt tension setting tool Hz
measurement: tension values).
Is the tension correct?
YES
With the engine stopped, use the diagnostic tool to
run command AC180 Air conditioning
compressor relay (injection command mode
menu).
Does the compressor clutch jam?
YES
E
NOReplace the belt (see MR 411
Mechanical, 11A, Top and front of
engine, Accessories belt: Removal -
Refitting).
NOConnect a test light between connections 38R
and MAS of component 171 and run
command AC180 Air conditioning
compressor relay.
Does the test light illuminate?
NO
Connect a test light between connection 38R
of component 171 and the chassis earth, then
run command AC180 Air conditioning
compressor relay.
Does the test light illuminate?
YES
Earth fault on component 171.
If there is a repair procedure
(see Technical Note 6015A,
Repairing electrical wiring,
Wiring: Precautions for
repair), repair the wiring,
otherwise replace it.
NO
F
YES
Check the condition of the
diode (component 322).
Replace the diode if it is faulty.
Replace the air conditioning
clutch (component 171) if
possible, otherwise replace
the compressor (see MR 411
Mechanical, 62A, Air
conditioning, Compressor:
Removal - Refitting).
AFTER REPAIRCarry out a complete check with the diagnostic tool.
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Diagnostic - Fault finding chart
Vdiag No.: 44
62B
ALP 8
CONTINUED 6
Check the continuity and insulation to earth of connection 38R between components 171 and 584.
Is the connection OK?
YES NO
Apply the fault finding procedure for command AC180
Air conditioning compressor relay (see 13B Diesel
injection or 17B Petrol injection).If there is a repair procedure (see Technical Note
6015A, Repairing electrical wiring, Wiring:
Precautions for repair), repair the wiring, otherwise
replace it.
F
AFTER REPAIRCarry out a complete check with the diagnostic tool.