Page 137 of 208
ANTIPOLLUTION
Exhaust gas recirculation (EGR)
14
1 EGR valve
2 EGR solenoid (ON/OFF)
3 Vacuum pump
4 Engine
5 Exhaust manifold
6 Inlet manifold
7 Air filter
8 Injection computer
9 Coolant temperature sensor
13046R
F8Q Engine
13045R
14-11
Page 139 of 208

ANTIPOLLUTION
Exhaust gas recirculation (EGR)
14
The EGR is controlled by the computer via an
ON/OFF solenoid valve.
The operation of the
EGR solenoid valve is de-
pendent upon the following parameters :
- the air temperature,
- the coolant temperature ,
- the altitude,
- the position of the load lever ,
- the vehicle speed ,
- the engine speed .
The EGR function is cut if :
- the air temperature < 16°C or
- the coolant temperature < 45°C or
- the engine speed/ load potentiometer value is
greater than a certain threshold .
The EGR is cut after operating at idle speed for 40
seconds (at zero vehicle speed).
Once the vehicle speed > 25 mph (40 km/h), the
EGR is operational again. It will be cut again after
40 seconds of operating at idle speed at zero ve-
hicle speed.
XR 25 bargraph 14 RH is illuminated if the EGR
function is permitted. In order to determine if the
EGR is actually controlled, use #24. if the value is
different from 0, the EGR is activated . F8Q Engine
14-13
Page 156 of 208
INJECTION
General
17
1 Coil
2 Air filter
3 Oxygen sensor
4 Absolute pressure sensor
5 Throttle position potentiometer
6 Idle regulation stepping motor
7 Air temperature sensor
8 Injection computer
9 Inertia switch
10 Locking relay
11 Fuel pump relay
12 TDC sensor
13 Fuel vapour recycling solenoid valve
14 Coolant temperature sensor
15 Tool for removing spark plug leads
16 Pinking sensor
17 Power assisted steering pressostat
18 Pressure regulator
19 Anti-interference condenser
20 Fuel vapour absorber (canister)
LOCATION OF COMPONENTS
13081
D7F Engine
17-6
Page 157 of 208
INJECTION
General
17
1 Fuel vapour recycling solenoid valve
2 Air filter
3 Pinking sensor
4 Absolute pressure sensor
5 Idle speed regulation stepping motor
6 Throttle position potentiometer
7 Air temperature sensor
8 Injection computer
9 Inertia switch
10 Fuel pump relay
11 TDC sensor
12 Coolant temperature sensor
13 Oxygen sensor
14 Coil for cylinders 2 - 3
15 Power assisted steering pressostat
16 Coil for cylinders 1 - 4
17 Fuel vapour absorber (canister)
18 Anti-interference condenser
LOCATION OF COMPONENTS
13082
E7J Engine
17-7
Page 158 of 208
INJECTION
Location of components
17
4 Absolute pressure sensor
5 Throttle position potentiometer
6 Idle speed regulation stepping motor
7 Air temperature sensor13 Fuel vapour recycling solenoid
14 Coolant temperature sensor 16 Pinking sensor
(tightening torque: 2.5 daN.m)
11313R4
11311R1
99939-1R2
8 Injection computer
9 Inertia switch
13051R1
D7F Engine
17-8
Page 160 of 208
INJECTION
Location of components
17
12 Coolant temperature sensor8 Injection computer
9 Inertia switch
13240R
3 Pinking sensor
(tightening torque: 2.5 daN.m)
13336R13239R
E7J Engine
17-10
Page 163 of 208

INJECTION
Coolant temperature management
244Injection coolant temperature sensor and
coolant temperature indication on
instrument panel.
3 track sensor, of which two tracks are
allocated to the injection coolant
temperature information, and one to the
indication of the coolant temperature on
the instrument panel.
259Warning coolant temperature switch for
instrument panel.
Operating principle
Sensor 244 allows :
- the coolant temperature to be shown on the
instrument panel,
- the injection computer to receive constant in-
formation on the engine coolant temperature
.
The injection computer, depending on the co-
olant temperature, controls :
- the injection system,
- the cooling fan assembly.
The engine cooling fan assembly is controlled
at fast speed (both slow and fast speeds are
controlled by the air conditioning system) if
the temperature is greater than 99°C. If the
temperature falls below 96°C, it cuts off
automatically ( if a check has to be carried out,
ensure that the air conditioning is not opera-
tional).
17
11634R2
D7F Engine
13239R1
E7J Engine
17-13
Page 167 of 208

INJECTION
Injection/air conditioning programming
17
THIS VEHICLE IS FITTED WITH A VARIABLE OUTPUT COMPRESSOR
AIR CONDITIONING/INJECTION COMPUTER CONNECTION
The electrical connection :
- between the air conditioning computer and the injection computer consists of a single wire (track 5).
This track carries two types of information :
-the fast idle speed request information . For this information to be transmitted to the injection
computer , two conditions must be fulfilled :
• the air conditioning function must have been selected on the control panel ,
• the pressure in the air conditioning circuit must be greater than a certain threshold.
If this information is transmitted, the fast idle speed is obtained (it is therefore normal that
sometimes, when the air conditioning is switched on, engine idling, there is no fast idle speed ).
-the Absorbed Power information. This information has no influence on the idle speed. It simply
informs the injection computer of the torque value taken up by the compressor; the computer, in
turn, acts on the idle speed regulation solenoid. The absorbed power may be visualised using the
XR25. When the air conditioning is switched on , #44 should be between 300 and 5 000 watts.
IMPORTANT: the value at #44 or idle speed is never equal to 0, whatever the status of the
compressor, off or on . The minimum value which may be read using #44 is approximately 300
watts.
- between the the injection computer and the air conditioning computer consists of a single wire (track
51). This track carries the information regarding the authorisation or prevention of compressor
operation.
COMPRESSOR OPERATION PROGRAMMING
During certain operating phases, the injection computer prevents the compressor from operating.
Programming when starting engine
The compressor is prevented from functioning for 10 seconds after starting the engine .
Recovery of performance ( D7F engine)
Depending on the torque required by the driver and on the power absorbed by the air conditioning
compressor, the injection computer stops or allows the operation of the compressor .
Anti-stalling function (D7F engine)
If the no load position is recognised , and the engine speed is lower than 600 rpm, and if the power absorbed
by the compressor is greater than 300 watts, the compressor disengages .
It engages again if:
- the no load position is recognised when the engine speed reaches 850 rpm.,
- if the no load position is not recognised when the engine speed reaches 1 800 rpm.
Thermal protection programming ( E7J engine )
The compressor does not engage in cases where the coolant temperature is greater than or equal to +
115°C.
Over-revving protection (E7J engine )
The compressor is prevented from operating if the engine speed is greater than 5 900 rpm.
17-17