RENAULT MEGANE SCENIC 1995 Service Repair Manual

DIESEL EQUIPMENT
Pump
13
92600R2
BBOSCH pump
RLUCAS DIESEL pump
Ckeyway to be used
13-25

DIESEL EQUIPMENT
Pump
13
REFITTING (Special notes)
To facilitate refitting the lower injection pump
mounting bolt, remove the injector holder for
cylinder n° 4 (when refitting, the copper seal and
the flame arresting washer must be systematically
renewed).
Refitting is the reverse of removal.
IMPORTANT : depending on equipment, the
pump drive sprocket has a different position.
There are two position markers and two
differently aligned keyways.
Fit the pump ensuring the key fits into the
sprocket (reference C).
Tighten the pump mounting nut to the
recommended torque (see previous pages).
Carry out pump timing (see method below).
13-26

DIESEL EQUIPMENT
Pump - timing
13
CHECKING THE PUMP TIMING
In place of the plug (1) insert the dial gauge
mounting Mot. 856 and attach a dial gauge with
socket.
99336R
Zero the dial gauge to BDC on the injection pump
piston.
Immobilise the engine using tool Mot. 1054. To do
this, turn the engine so that the camshaft sprocket
index is aligned with the timing cover reference
mark.
DI1303-1
99183R
Check the pump piston lift shown on the dial
gauge ; it should be 0.82 ± 0.04 mm. If it is not,
rotate the pump to obtain the required piston lift.
IMPORTANT : after tightening the pump
mounting bolts, turn the engine over twice.
Immobilise the engine once more to check the
pump timing.
13-27

DIESEL EQUIPMENT
Coded solenoid valve
13
REPLACEMENT
SPECIAL TOOLING REQUIRED
Mot. 1372 Kit for removing self shearing
bolts from computers
REMOVAL
This operation must be carried out with the
ignition turned off.
Remove the oil vapour decanter (1).
DI1410-1
Fit the drilling tube (2) from kit Mot. 1372 into the
computer.
Use:
- the 4 mm diameter drill from kit Mot. 1372 to
drill the two bolts (drilling depth
approximately 3 mm),
- the number 6 extractor from the kit Mot. 1372
to remove the bolts.
99780R
Remove the computer.
REFITTING
Use the self shearing bolts available from the Parts
Department.
Composition of kit Mot. 1372 :
- one 4 mm diameter drill (4)
- one number 6 extractor(3)
- one drilling tube (2)
NOTE :
- take care to remember to replace the plastic
cover on the solenoid valve nut,
- lightly oil the drill to facilitate drilling.
13-28

DIESEL EQUIPMENT
Operating diagram
13
PRJ99256
13-29

DIESEL EQUIPMENT
Pre-post-heating unit
13
DIAGRAM KEY
104Ignition switch
163Starter
171Air conditioning clutch
206Air conditioning trifunction pressure switch
247Instrument panel
251Bi-function coolant temperature switch
257Pre-heating unit
398EGR solenoid valve
412Fast idle solenoid valve (AC version)
597Engine fuse box
642AC / pre-heating separation diode
645Passenger compartment fuse box
680Pre-heating unit n° 1
681Pre-heating unit n° 2
682Pre-heating unit n° 3
683Pre-heating unit n° 4
711Diesel fuel pump
741Altimetric capsule
743Altimetric relay
777Power feed for fuse boxConnector (A)
+ Bat+ before ignition feed
Connector (B)
1Feed to heater plugs 1 and 3
2Feed to heater plugs 2 and 4
Connector (C)
A1 / S2Load dependence solenoid valve
control
A2 / PCLoad lever microswitch information
A3 / CTNCTN type sensor coolant temperature
information
B1/+APC+ after ignition feed
B2 / DEMStarter information
B3 / TemPre-heating warning light control (via
earth)
C1 / S1Not used
C2 / -Bat Earth
C3 / ClimFast idle solenoid valve control during
post-heating phase
92206-2R
IDENTIFICATION OF CONNECTORS
13-30

DIESEL EQUIPMENT
Pre-post-heating unit
13
LOCATION
Pre-post-heating unit (A)
This unit has two diodes to prevent the feeding of
the heater plugs when the air conditioning system
is operating and also has a CTN type air
temperature sensor.Coolant temperature sensor (1) (black connector)
99335R
BAir conditioning diaphragm control solenoid
valve on injection pump (fast idle)
CEGR control solenoid valve
98904R
SPECIFICATIONS
Temperature in °C ± 1Resistance Ω
252 610 to 2 990
80310 to 350
13-31

DIESEL EQUIPMENT
Pre-post-heating unit
13
PRINCIPLE OF OPERATION FOR GAS PRE-POST-
HEATING
1. "Pre-heating" when the ignition is turned on
a) Variable pre-heating
The time period during which the warning
light is illuminated and the heater plugs
are fed is dependent on the coolant
temperature.3. "Post-heating" while the engine is running
Post-heating has two phases:
a) Fixed post-heating
After the engine has been started, the
plugs are for for 10 seconds.
b) Variable post-heating
Variable post-heating begins when fixed
post-heating has ended.
During this phase, the plugs are fed
alternately 1 - 3 and 2 - 4 depending on
the coolant temperature.
If the coolant temperature sensor is faulty,
the heater plugs are fed systematically for
14 seconds.
b) Fixed pre-heating
After the pre-heating warning light has
extinguished (variable pre-heating), the
plugs remain fed for up to 8 seconds
before the engine is started.
2. Starting
The plugs remain fed while the starter is
activated.If the coolant temperature sensor is faulty,
the heater plugs are fed systematically for
30 seconds.
Variable post-heating may be
interrupted:
- finally when the coolant temperature
> 65°C,
- momentarily when the unit receives
full load information (post-heating
microswitch opens) for more than 1
second ; post-heating begins again
when the engine returns to idle speed
or low load (microswitch closes).
DI1304
DI1305
13-32

DIESEL EQUIPMENT
Pre-post-heating unit
13
FAULT FINDING
1. The pre-heating warning light does not operate
TEST SOLUTION
Earth the warning light output of connector (C) using
a 2 A fuse when the ignition is turned on (track B3).
• The fuse blows.
• The warning light does not illuminate.
• The warning light does illuminate.The warning light wiring in the instrument panel is in
short circuit. Repair the wiring.
The bulb is blown or the wiring is faulty.
Replace the bulb or repair the wiring.
Check:
- + battery on connector (A),
- + after ignition on connector (C),
- battery earth on connector (C).
If the feed is correct, replace the pre-post-heating
unit.
2. The pre-heating warning light only operates for a fraction of a second when the ignition is turned on.
TEST SOLUTION
Disconnect connector (B) and test the pre-heating:
• The warning light illuminates and there is a
voltage at the connector outputs (B).
• The warning light illuminates and there is no
voltage at the connector outputs (B).
• The pre-heating warning light illuminates for a
fraction of a second only.Check the plugs circuit. If it is correct, check and
replace the faulty plug(s).
Replace the pre-post-heating unit.
Check the before ignition feed to the pre-heating
unit.
13-33

DIESEL EQUIPMENT
Pre-post-heating unit
13
FAULT FINDING
3. There is no fast idle when engine is cold (with air conditioning option)
TEST SOLUTION
Run the air conditioning.
• The fast idle operates
• The fast idle does not operate.Check the connections at the pre-post-heating unit
(connector C).
Ensure continuity between track C3 of connector (C)
and track 1 on the solenoid valve.
Replace the pre-post-heating unit (ensure the
warning light operates correctly when the ignition is
turned on).
If the fast idle solenoid valve opens the pneumatic
circuit, repair the circuit between the vacuum pump,
the solenoid valve and the diaphragm.
If the solenoid valve does not open the circuit,
measure the voltage between the 2 tracks on the
solenoid valve connector.
•12 volts
Replace the solenoid valve after testing the
connections.
•0 volt
Ensure the following continuities :
- between track 2 on the connector and earth,
- between track 1 and track C3 of the pre-post-
heating unit.
13-34