Page 96 of 208
DIESEL EQUIPMENT
Location of components
13
1 EGR valve and solenoid valve
2 Air temperature sensor (white connector)
3 Coolant temperature sensor (white connector)
4 Diesel injection computer
5 Fuel filter
6 Pre-postheating plug relay housing
7 TDC sensor
8 Fast idle solenoid valve
9 Electrical solenoid / coded solenoid
10 Digital DPC injection pump
11 Load potentiometer
12 Advance solenoid valve
13 Altimetric corrector
14 Injector with sensor (needle lift)
12874
13-16
Page 97 of 208
DIESEL EQUIPMENT
Location of components
13
12Advance solenoid valve
14Injector with sensor
13Altimetric corrector
11Load potentiometer
9Electrical solenoid / coded solenoid valve
8Idle speed solenoid valve
12869-1R
3Coolant temperature sensor
2Air temperature sensor
6Pre-postheating plug relay housing
5Fuel filter
16Inertia switch
4Injection computer
13083R
12872R
19 EGR solenoid valve
12871R
13-17
Page 113 of 208

DIESEL EQUIPMENT
Pre-postheating control
13
The pre-postheating function is controlled by the
computer, which controls the preheating plug re-
lay housing.
1) Ignition - Preheating
The preheating process is divided in two
phases :
a) Variable preheating
This is dependent on the coolant tempera-
ture, on the battery voltage and on alti-
tude (internal computer sensor) when the
ignition is switched on (the preheating
warning light illuminates).b) Fixed preheating
After the preheating warning light has
extinguished (variable preheating), the
plugs remain fed for 8 seconds before the
engine is started.
2) Starting the engine
During the action of the starter motor, the
four plugs are fed continuously.
3) Engine running - Postheating
The postheating also may be divided in two
phases:
a) Fixed postheating
After starting the engine, the plugs are
supplied simultaneously for a period of 10
seconds.
b) Variable postheating
Variable postheating begins when fixed
postheating ends. The time during which
the plugs are fed (continuously) depends
upon :
- the coolant temperature
- the engine speed ,
- the load (load potentiometer on pump
lever ).
Maximum preheating limit (battery vol-
tage lower than 9.3 volts and altitude hi-
gher than 2 000 m).
Minimum preheating limit (battery
voltage greater than 10.5 volts altitude
lower than 350 m).
13041S
13-33
Page 114 of 208
DIESEL EQUIPMENT
Pre-postheating control
13
- 20 180time (s)
For an idle speed and load lever
position
Coolant temperature °C0204060
Variable postheating may be interrupted :
- permanently, if the coolant temperature is >
60°C,
- temporarily , if the unit receives full load
information for more than 3 seconds; the
function is established once again if the
engine returns to idle speed or low load,
- temporarily again if the battery voltage is
>16 V; the function is restored if Ubatt
< 15 V.
In all cases, the total duration of the postheating
function will never exceed 3 minutes.
13-34
Page 115 of 208

DIESEL EQUIPMENT
Fast idle speed control
13
- if the engine speed falls to 650 rpm and the
vehicle speed is lower than 15 mph (25 km/h)
(engine start improvement programming).
The fast idle speed is cut off once the speed
becomes > 850 rpm
NOTE :
- Fast idle speed operational :
• solenoid valve not operated,
• cable loose, and not tensioned.
- Nominal idle sped :
• solenoid valve operated
• cable tensioned
SPECIAL FEATURES : once the AC has been
selected on the instrument panel, the fast idle
speed function is activated. The fast idle speed function is controlled by the
computer via a solenoid valve operating the dia-
phragm (versions with or without air conditio-
ning).
The fast idle speed control becomes operational :
- if, on switching on the ignition, the coolant
temperature is below 10°C,
Coolant
temperature
on switching
ignition on (°C)Fast idle speed
cut-off
temperature
(°C) Fast idle speed
cut-off
temperature
(°C)
10
5
0
- 10
- 2020
20
30
40
5011
15
20
25
30
F8Q 662F8Q 630
13-35
Page 117 of 208
DIESEL EQUIPMENT
Computer
13
PRM1316
CONNECTION
1-<-
2-----
3-----
4-->-
5-->-
6-->-
7-<--
8-<--
9-->-
10-<--
11-<--
12-<--
13-><-Computer supply
Computer earth
Sensor earth
Potentiometer lever supply
EGR solenoid control
Advance corrector control
Needle lift signal
Engine speed signal
Preheating warning light control
Fault finding information line L
AC status
Vehicle speed signal
Fault finding information line KPlug relay control
Altimetric corrector relay control
Fast idle speed control
Load lever position information
Fault finding warning light control
AC prevention control
Power assisted steering pump assembly
relay control
Engine speed information
Not used
Load lever signal
Air temperature signal
Coolant temperature signal14-->-
15-->-
16-->-
17-->-
18-->-
19-->-
20 -->-
21-----
22
23-<--
24-<--
25-<--
13-37
Page 118 of 208

DIESEL EQUIPMENT
Defect modes
13
If there is a fault with one of the components listed below, the computer enters "defect mode", which means
that replacement values are used to ensure engine operation.
Faulty
componentSet values (for replacement)
Advance
corrector Pre-postheating
timeEGR function Fast idle speed AC function
Coolant sensorRunning time
functionPreheating : -
30°C
Postheating :
80°CCutRunning time
function-
Air sensorTemperature
= 22°C- Cut - -
Load
potentiometer100 % load lever
positionPostheating:
30 % load lever
position Cut - 20 % load lever
position
Altitude sensorAltitude
= 900 mAltitude
= 900 mCut - -
Battery
16 V < U < 6 VUbatt = 13.5V Not controlled - - -
TDC sensorMinimum
advance
Solenoid valve
fully open
position Postheating :
Not controlled
until ignition is
switched off
then on againCutSpeed
= 2 000 rpmSpeed
= 2 000 rpm
Needle lift
sensorDefect mode
advance
(Carto soft
F8Q 662)
Maximum
advance
(F8Q 630)----
Vehicle speed
sensor--Position :
V = 175 km/hPosition :
V = 175 km/hPosition :
V = 175 km/h
Heater plugs
relay housing- Cut - - -
13-38
Page 130 of 208

ANTIPOLLUTION
Fuel vapour rebreathing
14
CONDITION FOR BLEEDING THE CANISTER ( D7F
engine)
• Coolant temperature greater than+ 15 °C
•Air temperature greater than +10 °C.
• No load position not recognised (if there is a
fault in the throttle potentiometer sensor, the
condition of no load position not recognised is
replaced by an engine speed condition
R > 1500 rpm.).
It is possible to visualise the cyclical opening ratio
for the canister bleed solenoid using the
XR25
and #23. The solenoid is closed if #23 = 0.7 %
CONDITION FOR BLEEDING THE CANISTER (E7J
engine)
During richness regulation
Coolant temperature greater than 50°C.
Air temperature greater than 15°C.
No load position not recognised (if there is a fault
in the throttle potentiometer sensor, the
condition of no load position not recognised is
replaced by an engine speed condition
R > 1500 rpm.).
Outside richness regulation
•Coolant temperature greater than 50°C.
•Air temperature greater than 15°C.
•Full load position recognised (function of
engine speed and manifold pressure).
If there is a fault in the oxygen sensor, bleeding is
permitted outside of no load conditions.
It is possible to visualise the cyclical opening ratio
for the canister bleed solenoid using the
XR25
and #23. The solenoid is closed if #23 = 0.7 %
(minimum value).
14-4