Page 92 of 118

Downloaded from www.Manualslib.com manuals search engine DIESEL EQUIPMENT
Coolant temperature management
13
13-41
Coolant temperature management
CCTM
This system allows the engine cooling fan to be
controlled by the injection computer. It consists of a
single coolant temperature sensor serving injection,
the engine cooling fan, the temperature indicator and
the instrument panel temperature warning light.OPERATION
The injection computer controls, as a function of the
coolant temperature:
– the injection system,
– the engine cooling fan relays:
!the fan is kept at a low speed if the coolant
temperature exceeds 99 ˚C and stops when the
temperature drops below 96 ˚C,
!the fan is kept at a high speed if the coolant
temperature exceeds 102 ˚C and stops when the
temperature drops below 99 ˚C,
!the fan can be controlled by the air conditioning.
For vehicles without air conditioning, only the low
speed engine cooling fan is operational.
COOLANT TEMPERATURE WARNING LIGHT
(shared with the injection fault warning light)
The warning light is controlled by the computer.
It is illuminated when the temperature exceeds 120 ˚C.
16179R1
244 Coolant temperature sensor (injection and
coolant temperature indication on the
instrument panel).
Three track sensor, two tracks for coolant
temperature information and one track for
indication on the instrument panel.
Page 93 of 118

Downloaded from www.Manualslib.com manuals search engine DIESEL EQUIPMENT
Computer
13
13-42
Computer
TRACK ASSIGNMENT
Connector A
H2
H3
H4
G1
G2
G3
G4
F1
F3
F4
E1
E2
E3
E4
D3
D4
C1
C3
B1
B3
A3---
→
→
→
←
→
←
←
←
→
---
←
→
←
→←
→
←
→←
→
---
---THROTTLE POTENTIOMETER SUPPLY (TRACK 2)
OBD WARNING LIGHT
COOLANT TEMPERATURE WARNING OUTPUT
PREHEATING WARNING LIGHT OUTPUT
IMMOBILISER INPUT
FAULT WARNING LIGHT OUTPUT
POWER CONSUMED
THROTTLE POTENTIOMETER INPUT (TRACK 2)
FUEL CUT-OFF SOLENOID INPUT
AIR CONDITIONING INHIBITION OUTPUT
THROTTLE POTENTIOMETER SUPPLY (TRACK 1)
CLUTCH BREAKER INPUT
CONSUMPTION INFORMATION OUTPUT
VEHICLE SPEED INPUT
FAULT FINDING
ENGINE SPEED INFORMATION
THROTTLE POTENTIOMETER INPUT (TRACK 1)
FAULT FINDING
HEATED REAR WINDSCREEN INPUT
THROTTLE POTENTIOMETER EARTH (TRACK 1)
THROTTLE POTENTIOMETER EARTH (TRACK 2)
Connector B
B3
B2
C3
C2
C1
D4
D3
D1
E3
E1
F2
G3
G2
G1
H4
H3
H2
J3
J2
K3
L4
L3
L2
L1
M4
M3
M2
M1←
---
→
←
←
→
←
←
---
---
---
←
---
---
←
←
---
←
---
←
---
---
→
→
---
---
---
→PLUGS DIAGNOSTICS INPUT (1)
EGR POTENTIOMETER POSITION EARTH
PREHEATING RELAY CONTROL
EGR POTENTIOMETER POSITION SIGNAL INPUT
TURBOCHARGER PRESSURE INPUT SENSOR
SUPPLY RELAY CONTROL OUTPUT
AIR TEMPERATURE SENSOR INPUT
DIESEL PRESSURE INPUT SENSOR
+ AFTER IGNITION FEED
COOLANT TEMPERATURE SENSOR EARTH
EGR POTENTIOMETER POSITION SUPPLY
ENGINE SPEED SIGNAL SENSOR
AIR FLOW METER SUPPLY
FUEL TEMPERATURE SENSOR EARTH
AIR FLOW METER SIGNAL INPUT
ENGINE SPEED SIGNAL SENSOR
DIESEL PRESSURE SUPPLY SENSOR
FUEL TEMPERATURE INPUT
TURBOCHARGER PRESSURE SUPPLY SENSOR
COOLANT TEMPERATURE SENSOR INPUT
POWER EARTH
POWER EARTH
TURBO PRESSURE SOLENOID VALVE CONTROL OUTPUT
PRESSURE REGULATOR SOLENOID VALVE CONTROL OUTPUT
POWER EARTH
+ AFTER RELAY
+ AFTER RELAY
EGR SOLENOID CONTROL OUTPUT
Page 97 of 118

Downloaded from www.Manualslib.com manuals search engine ANTIPOLLUTION
Exhaust gas recirculation
14
14-3
OPERATING PRINCIPLE
The valve is controlled by an RCO signal issued by the
injection computer. The RCO signal permits
modulation of the opening of the valve, and
consequently, the quantity of exhaust gas directed
back towards the inlet manifold.
The computer continuously carries out a test to detect
the position of the EGR valve flap.
OPERATING CONDITIONS
The parameters which determine the actuation of the
EGR valve are as follows:
– the coolant temperature,
– the air temperature,
– the air pressure,
– the accelerator pedal position,
– the engine speed.
The EGR function is cut if:
– the battery voltage is less than 9 volts,
– the engine speed is greater than 3000 rpm.,
– a characteristics map (engine speed/load) exceeds a
given threshold,
– the vehicle speed is less than 12 km/h, the engine
speed is less than 1000 rpm and if the coolant
temperature is greater than 60 ˚C for 40 seconds.
The EGR valve is not supplied after engine start
according to a coolant temperature characteristics
map.
time (s)The electric EGR valve is supplied for 40 seconds on
each return to idling speed if the air temperature is
greater than 15 ˚C.
Coolant
temperature (˚C)
15761R
1
2
4
5
6Solenoid supply
Sensor supply
Sensor earth
Solenoid earth
Sensor output
-20 0 17 20
Page 103 of 118
Downloaded from www.Manualslib.com manuals search engine COOLING SYSTEM
Filling and bleeding
19
119 COOLING SYSTEM
Filling and bleeding
There is no heater matrix water control valve.
Water flow is continuous in the heater matrix, which
contributes to the cooling of the engine.
FILLING
It is essential to open the bleed screw on the
cylinder head coolant pipe housing outlet.
Fill the circuit through the expansion bottle opening.
Close the bleed screw as soon as the fluid runs out in
a continuous jet.
Start the engine (2500 rpm).
Adjust the level by overflow for a period of about
4 minutes.
Tighten the expansion bottle cap.
BLEEDING
Let the engine run for 20 minutes at 2500 rpm, until
the engine cooling fan operates (time required for
automatic degassing).
Check the liquid level is at the "Maximum" marker.
DO NOT OPEN THE BLEED SCREW(S) WITH THE
ENGINE RUNNING.
REFIT THE EXPANSION BOTTLE CAP WHILE THE
ENGINE IS WARM.
19-1
Page 105 of 118
Downloaded from www.Manualslib.com manuals search engine COOLING SYSTEM
Thermal plunger unit
19
19-3
Thermal plunger unit
REMOVAL
Put the vehicle on a 2 post lift.
Disconnect the battery.
Remove the engine undertray.
Position the hose clips at the inlet and outlet of the
thermal plunger mounting unit (plugs).
Disconnect the hoses on this unit.
Remove the mounting bolt for the thermal plunger
support unit as well as the supply wires and remove
the unit.
REFITTING
The plugs are tightened in the usual fashion.
Refitting is the reverse of removal.
Top up the coolant and bleed the cooling circuit (see
section 19 "Filling - bleeding"). SPECIAL TOOLING REQUIRED
Mot. 453 -01
Mot. 1202
Mot. 1448Hose clamp pliers set
Hose clip pliers
Long nose pliers for hose clips
TIGHTENING TORQUES (in daN.m)
Thermal plungers 2
Page 107 of 118

Downloaded from www.Manualslib.com manuals search engine COOLING SYSTEM
Water pump
19
19-5
Water pump
REMOVAL
Put the vehicle on a two post lift.
Disconnect the battery.
Remove the engine undertray.
Drain the cooling circuit through the lower radiator
hose.
Unclip the diesel filter and remove it.
Remove:
– the front right wheel along with the mudguard,
– the style cover,
– the accessories belt (see Section 07 "Accessories
belt tension"),
– the coolant pump and power assisted steering pump
pulleys,
– the water pump.Cleaning
It is very important not to scratch the gasket faces.
Use the Décapjoint product to dissolve any part of the
gasket which remains attached.
Wear gloves whilst carrying out the following
operation.
– Apply the product to the parts to be cleaned; wait
about ten minutes, then remove it using a wooden
spatula.
Do not allow this agent to drip on to the paintwork.
REFITTING
Refit:
– the water pump (fitted with a new gasket), tightening
the bolts to a torque of 1.7 daN.m,
– the accessories belt and tension it (see section 07
"Accessories belt tension").
Fill and bleed the cooling circuit, (see section 19
"Filling and Bleeding"). SPECIAL TOOLING REQUIRED
Mot. 1202 -01
Hose clip pliers
Mot. 1202 -02
Mot. 1448 Long nose pliers for hose clips
TIGHTENING TORQUES (in daN.m)
Water pump bolts 1.7