Tài liệu sửa chữa xe ô tô Renault 19 (Repair Manual) - P4

Tài liệu sửa chữa xe ô tô Renault 19 (Repair Manual) Chassis, Heating and ventilation, Sheet metal work, Sealing and Soundproofing, Trim and Upholstery

77 11 190 859 NOVEMBER 1996 Edition Anglaise

Heating and ventilation

"The repair methods given by the manufacturer in this document are based on the

technical specifications current when it was prepared.

The methods may be modified as a result of changes by the manufacturer in the

production of the various component units and accessories from which his vehicles

are constructed".

All copyrights reserved by Renault.

Copying or translating, in part or in full, of this document or use of the service part reference numbering system is forbidden without the prior written authority of Renault.

HEATING AIR CONDITIONING

PRJ6000

C Air outlet in rear left hand wing

a Central ventilator outlets

b Windscreen de-mister outlet

c Dashboard ventilator outlet

d Lower ventilator outlets

e Rear seat ventilator outlets (depending onequipment level)

f Front side windows de-mister outlet

General 61

a Central ventilator outlets

b Windscreen de-icer / de-mister outlets

c Dashboard ventilator outlets

d Lower outlets

e Rear seat ventilator outlets (depending on equipment level)

f Front side window de-mister outlet

Phase II

1 Heater radiator

2 Heater fan

3 Hot / cold air flap

4 Air distribution flaps

5 Air distribution cable

6 Air mixing cable

a Air intake

b Windscreen de-misting outlet

c Dashboard ventilator outlets

d Lower ventilator outlets

e Rear seat ventilator outlets (depending on

equipment level)

EXPLODED VIEW OF THE FAN AND DISTRIBUTION UNIT

WATER BOX

PASSENGER COMPARTMENT

95717R2 92033-5R

TEMPERATURE CONTROL KNOB (A)

Controls the hot / cold air flap (3).

The fan has no heater valve and is permanently fed Flap (3) controls the fresh air heating system.

92196-1R

95717R3

AIR DISTRIBUTION KNOB (B)

Controls the air distribution flaps (4).

POSITION

The air flow is directed only to the dashboard

ventilators (a) and (c).

Each ventilator has three settings :

- open or closed,

- up or down,

- left or right

Ventilation is by means of blown air The amount

of air circulating in the passenger compartment is

determined by the position of knob (C).

NOTE : To improve de-misting and de-icing of the

windscreen, fan control knob (C) should be on the

last but one position (2)

POSITION

The air flow is directed to the lower ventilators

(d), (e) and the dashboard ventilators (a) and (c).

POSITION

The air flow is directed to the windscreen

ventilators (b), the side window ventilators (f), and the dashboard ventilators (a) and (c).

To improve de-misting and de-icing of the

windscreen, ventilators (a) and (c) may be closed.

POSITION

The air flow is distributed between all the

ventilators (a), (b), (c), (d), (e), (f).

The dashboard ventilators (a) and (c) may be

closed

FAN CONTROL KNOB (C)

92200R

92283R

Fit hose clamps Mot 453-01 or Mot 583.

SPECIAL TOOLING REQUIRED Mot 453 -01 Hose clamp

REMOVAL

Disconnect the battery

Remove:

- the dashboard (refer to relevant section),

- the upper seal on the water box and the

external air intake grilles

Disconnect the fan feed connector (A).

Remove the 2 fan mounting bolts (B) and remove

the fan from the driver’s side (the water box can

only be removed in one position)

Remove:

- the 2 radiator inlet hose clips,

- the fan unit from inside the vehicle togetherwith its control

92203R1

REFITTING

Fit the fan unit on the bulkhead (ensure that the

seals are in good condition)

Fit the fan with the 2 fan mounting bolts (B) Do

not tighten these two bolts The fan unit is also

positioned on the dashboard by two bolts (C).

Refit the dashboard

Check the control cable adjustment and re-adjust

if necessary (see corresponding section)

Connect the radiator hoses

Tighten the 2 fan mounting bolts (B) and refit the

feed connector (A).

Refit the air intake grilles and the water box seal

Top up and bleed the engine cooling circuit (see

corresponding section) if necessary

The fan unit is removed after removing the upper

water box seal and the external air intake grille

Remove the feed connector (A) and the 2

mounting bolts (B).

Remove the fan from the left hand side of the

vehicle (the water box can only be removed in one

position)

Disconnect the motor connector

Open the two half covers

Pull the motor out as shown below

When refitting, put the motor back in position sothat the connector is not taut

Refasten the two half covers using the clips (D)

provided in the kit and hot-crimp them

Fit the new seal provided in the kit to theassembly

IMPORTANT: the seal must be in perfectcondition If it is damaged, water may enter thepassenger compartment

Spread the 4 retaining clips (E) and remove the

radiator by pulling in the direction shown in the

diagram below

NOTE: take care not to damage the radiator fins

When refitting, ensure that the radiator is fitted

into the holder with its foam adjustment strips

Ensure that the 4 tabs are correctly fastened

Fit the 2 mounting bolts (F) onto the body of the

fan unit if the clips have broken

92283R1

REPLACEMENT

The resistance unit is reached after removing the

water box upper seal and the external air intake

grille

Disconnect connector (A) and remove the two

mounting bolts (G).

Detach clips (H) and remove the resistance unit.

NOTE: if the resistance unit is being removed due

to damage, ensure that the fan rotates freely,

otherwise change it

There are no special precautions for refitting the

resistance unit

92288R 92289R1

REPLACEMENT

Remove the two mounting bolts for the lower

dashboard cover (J).

Remove the two mounting bolts securing the

control panel to the dashboard (K).

When refitting, change the cable sleeve stops and

the clips (M).

Push the control panel in and release it from the

bottom

The control panel facade may be changed by

removing the 4 retaining clips (L).

92289R1 92207R

92224R1 92203R

REPLACEMENT

The control cables can be removed without

removing the air distribution unit

Remove:

- the control panel as described on the previous

page,

- the 2 mounting bolts for the air deflector (N).

Place the air distribution control inposition and the heating control onmaximum cold (blue spot)

Refit the control panel to the air distribution unit.Align the flap control quadrant markers

Unclip the cable to be changed and turn it 1/4

turn to release it from the flap control lever

When refitting,clip the cable to the control panel

against the cable sleeve stops (clips M).

Refit:

- the mixing flap return spring (P) (only for air

mixing control),

- the air deflector and the lower dashboard

cover, bolts (N) and (J).

NOTE: the flap control cables are of a differentlength, the longer one is for the mixing flap

General 62

91096-1R

5 High pressure bleed

6 Pressure relief valve

7 Thermostat control for pressure relief valve

8 Evaporator

9 Low pressure bleed

10 Air conditioning fan

11 Cooling fan

12 Engine radiator

13 High pressure liquid

14 Low pressure vapour

15 High pressure vapour

General 62

RECOMMENDATIONS

The quality of heating and ventilation repairs is

highly dependent on the rules below being

followed:

Never leave:

- the pipes open to the air; risk of moisture

being absorbed,

- a can of oil open

When topping up the oil using filling equipment:

• Never use oil left over from a previous

operation Use the exact quantity of oil

required for each operation

• Work cleanly The smallest foreign body at the

unions could cause slow leaks or internal

malfunction

• Do not allow oil to come into contact with the

vehicle’s paintwork or plastic components

• Emphasise the importance of operating the

air conditioning system regularly, both in

summer and in winter

• The system must be filled with the correct and

precise quantity of refrigerant (refer to the

"Consumables" section) Too much or not

enough refrigerant reduces the performance

of the system and in extreme cases risks

damaging the compressor

• Never fill an air conditioning system which

operates using R134a with R12 refrigerant

and vice versa

Every year, it is recommended that:

1. the quantity of refrigerant in the airconditioning circuit is checked

2. the condenser and the engine coolingradiator are cleaned

3. the condition of the air conditioning systemcondensation outlet is checked (blockage) For the repair of major leaks, each time acomponent is changed (compressor, condenseretc ) or if the presence of moisture in the circuit issuspected, change the dehydrating bottle andcreate a vacuum The same applies if the air

conditioning circuit has been left open for more than 10 minutes without being plugged.

If the air conditioning system is not operated for

a prolonged period

If the system is not operated for a prolongedperiod, in particular in winter, operate thecompressor periodically in order to preventdestruction of the compressor rotor bearing races.The needles mark the bearing races when theassembly is immobilised in one position andvibrate under the effect of the engine rotation This destruction is manifested by significant noisewhen the compressor is operated again

A External air intake

B Recycled air intake

C To air distribution unit

NOTE : the air distribution unit and the dashboardare identical for versions with heating and

ventilation and versions with air conditioning

1 Fan unit

2 Fan

3 Evaporator

4 Fan control unit

5 Evaporator temperature sensor

6 Recycling motor

7 Pressure relief valve

8 Component unit

Operating principle 62

Principle of the system

In order to improve moving away when on a slope

and to avoid stalling the engine, the air

conditioning compressor clutch is cut for 4

seconds

Conditions

The clutch pedal must be depressed and the

accelerator pedal must be over a certain engine

load

Operation

When the two conditions above are fulfilled

(switch circuit open), relay (661) cuts out and no

longer feeds the timer relay (635).

The AC compressor clutch control relay (584) is

therefore cut for 4 seconds by the timer relay

Note

The diode stops the AC compressor clutch from

being fed by the pre-heating unit during starting

and engine warming

Special notes

The clutch pedal switch does not require anyspecial adjustment, other than when the clutchpedal is not depressed, the switch plunger should

be fully depressed

Using an ohmmeter:

clutch pedal not depressed:

- switch resistance = 0 ohm clutch pedal depressed:

- switch resistance= infinity SPECIFIC OPERATION FOR DIESEL AND TURBO DIESEL VERSIONS (see diagram on following page).

AIR CONDITIONING CUT-OUT

95718R2 92034-2R3

PHASE I

TEMPERATURE CONTROL KNOB (A)

This control has the same function as described in

the heating and ventilation section when the air

conditioning control (D) is in position 0.

When the air conditioning control (D) is in the

position "NORM" or "MAX", air is first cooled and

dried by crossing the evaporator, then some of it

is heated by crossing the radiator

When the control is turned to the extreme left,

the air is not heated and is therefore at its coolest

possible temperature

Moving the knob to the right allows the air

temperature to be controlled

PHASE II

AIR FLOW CONTROL KNOB (C)

This control has the same function as described inthe heating and ventilation section

There are 6 positions for fan speed in comparison

to the 3 positions for the heating and ventilationversion

POSITION 0: there is no ventilation, the air intake

is closed by the recycling flap

The air conditioning system cannot be operated.This position shuts off the complete system,whatever the other control knob settings may be

Operating principle 62

AIR CONDITIONING CONTROL KNOB (D)

This control starts and stops the air conditioning

system

Its use allows:

- the air temperature in the passenger

compartment to be lowered,

- the humidity level in the passenger

compartment to be reduced (improves

de-misting)

POSITION 0: air conditioning is not operational,

the vehicle has the same heating and ventilation

system functions as a vehicle without air

conditioning

POSITION "NORM": air conditioning is

operational This is the normal position for air

conditioning use Fresh air is taken from outside

the vehicle and constantly renewed

POSITION "MAX": air conditioning is operational

Air is taken from inside the passenger

compartment and recirculated No air is taken

from outside

This position allows the passenger compartmenttemperature to be lowered quickly and alsoisolates the passenger compartment from theexternal atmosphere ( driving in polluted areas)

If this position is used for a prolonged period oftime, there may be a slight misting up of the air inthe passenger compartment

It is therefore advisable to return to the "NORM"

position as soon as the polluted area is left or thedesired passenger compartment temperature isreached

NOTE:The air conditioning control only starts the

system operating if the air flow control (C) is set to

a position other than 0.

Operating principle 62

SPECIAL NOTES ABOUT THE SYSTEM

The temperature of the air from the evaporator is

not adjustable It is automatically controlled by

the electronic thermostat and the sensor (S).

Moving the mixing flap control knob (A) allows

the desired air temperature to be set

92287R

Fault finding - Customer complaints

Air conditioning

Air flow problem

Recycling flap does not operate - Model year 1989 and 1990 Chart 4

Recycling flap does not operate - From model year 1991 Chart 5

Passenger compartment fan does not operate

Passenger compartment fan does not operate

Air distribution problem when distribution control is in position : Chart 9A

Chart 9B

Engine cooling fan problem

Engine cooling fan only operates slowly Chart 6

Passenger compartment problems

e53531.1

62

Fault finding - Fault charts

AC and fan on max,

engine at idle speed

Does the compressor operate ?

Check the compressor belt tension, the

clutch air gap and its condition (slipping)

Change the belt or the compressor

clutch

Does the fault persist?

FAULT CHART N° 1 : Lack of efficiency

no See Chart 1A

Correct

Check the evaporator sensor

resistance (*).

Change the sensor if necessary

Does the fault persist?

Is there an air flow problem ?

Check that the recycling flap is in the recycling

position when AC is at max

Is this correct ?

Check that the mixing flap moves correctly and

readjust the cable if necessary

Does the fault persist?

no

no

Correctno

* If the sensor resistance is incorrect :

1) above max level :the compressor operates tooearly and reduces its efficiency.2) below min level :

the compressor operates toolate, the evaporator freezes,reducing its efficiency and theair flow

See Chart 4A (from model year 91)

Chart 4B (up to model year 90)

Fault finding - Fault charts

FAULT CHART N° 1 : Lack of efficiency (cont)

Check the operation of the engine cooling fan at

top speed (passenger compartment fan and AC on

max.)

Fan operates if HP ≥19 bars

Fan stops if HP ≤ 16 bars

Fan operates for engine coolant temperature ≥

92°C

Is the fan operation correct?

yes

Check that the sensor harness is clean

Clean or change the condenser

Does the fault persist?

no

Correctno

yes

yes

noCorrect

no

Adjust the refrigerant level in the circuit There

may have been too much refrigerant

The humidity in the circuit may haveformed a plug of ice in the pressurerelief valve or the valve may be faulty(slight lack of gas in the bulb)

Change the dehydrating bottle and thepressure relief valve and top up therefrigerant level

Pressures 16/19 bars ± 1.5 bar

NOTE: If the setting is too high the fan switches on and off too late and thus reduces the efficiency of the AC system

Change the pressostat if necessary

Does the fault persist?

yes

Connect the HP/LP pressure gauges and check the

pressures.Vehicle stationary, engine at idle speed

andA/C MAX.

If the HP>25 bars :

- there is too much refrigerant in the circuit,

- the engine cooling fan is not operating

correctly,

- the engine is getting too hot,

- the condenser is dirty.The compressor

operates via the HP pressostat under these

precise conditions

Is HP < 25 bars ?

e53531.1

62

Connect the HP and LP pressure gauges.

Check the operation of the engine cooling fan at

top speed ( AC on max.)

- Fan operates if HP ≥ 19 bars

- Fan stops if HP ≤ 16 bars

- Fan also operates for engine coolant

temperature ≥ 92°C

Is the fan operation correct?

Fault finding - Fault charts

Engine running at idle speed,AC and fan still on

max., check for bubbles in the dehydrating bottle

inspection glass

If bubbles are seen, there is not enough

refrigerant in the circuit Adjust the level

Does the fault persist?

FAULT CHART N° 1A : Lack of efficiency

yes See Chart 1

Correctno

Check the pressures (passenger compartment fan

With the windows and doors closed, the vehicle in

a shady location, temperature ≤ 25 °C, engine

idling, passenger compartment fan and AC on

max., measure the temperature of the air in the

central ventilator and check that the compressor

operates for a temperature < 4°C

Is this correct?

If various operations have been carried out on

the cooling equipment and oil has been

added, there may be too much oil in the circuit

(*).

If this is the case, remove the compressor

and check its oil level (see method in the A/C

workshop repair manual), drain the oil in the

pipes and the condenser, change the dehydrating

bottle and adjust the refrigerant level

Does the fault persist?

no

no

* Attention: type 709 compressorscirculate more oil in the circuitthan 508 type compressors

no

Correctno

If the fan control pressostat pressure settingsare too high, the fan starts and stops too lateand reduces the AC efficiency

If this is the case, change the pressostat

Check the evaporator sensor resistance

Change the sensor if necessary

Does the fault persist?

yes Change the pressure relief

valve and adjust therefrigerant level

Fault finding - Fault charts

Check the fuse or fuses, change if necessary

Does the fault persist?

FAULT CHART N° 2.1 : No cool air

yes See Chart 2.2

Correctno

Check for + 12 volts on

tri-function pressostat connector

Press on a filling valve to see if there isrefrigerant in the circuit

NOTE: with the engine stopped and cold,the pressure gauges should read

between 5 and 7 bars HP and LP for

a workshop temperature of 20/25°C

Is this correct ?

no

ye Check the clutch resistance (3.2 ± 0.5 ohms)

Change the clutch if necessary

Shunt the tri-functionpressostatbetween tracks A1 and C1 andcheck if the compressor operates

Does it operate ?yes

Adjust the refrigerant

Check the wiring between :

- track C1 on pressostat and thecompressor connector.(1)

62

Year of manufacture 1989 ; 1990 X533 ; X536 ; X537

Fault finding - Fault charts

FAULT CHART N° 2.1 : No cool air (cont)

A/Cand passenger compartment fan

on max

Shunt the evaporator sensor and

check if the compressor operates

Does it operate?

no

A/C and passenger compartment fan

on max

Check for + 12 volts on output from

electronic thermostat unit track 5 or

track B1 of black connection R99 of

- A5 of brown connection R34 and

A1 of the tri-function pressostat

yes Change the evaporator sensor

A/C and passenger compartment fan

Fault finding - Fault charts

Check for bubbles in the inspection glass of the

dehydrating bottle, engine idling, A/C on max

Are there bubbles ?

FAULT CHART N° 2.2 : No cool air (cont)

no See Chart 2.1yes

yesDoes the compressor operate?

See Chart 8Air distribution problem

Adjust the refrigerant level

Check that the mixing flap moves when the

Does the fault persist?

Connect the HP and LP pressure gauges and check

the pressures, engine idling, AC on max

If HP=LP the pressure relief valve is fully open or

if LP ≤ 0 bar the pressure relief valve is closed

If you read these values change the pressure relief

valve and adjust the refrigerant level

Does the fault persist?

Correctno

Correctno

nono

Change the tri-function pressostat

Fault finding - Fault charts

FAULT CHART N° 2A : No cool air- X53A vehicles (E7J 700), X53Y Bosch monopoint injection, X539, X53D, X53F Siemens multipoint injection

no See Chart 2F

Check for + 12 Volts on track 3 of relay 474

Is there + 12 Volts ?

Check the wiring between track 3

of relay 474and the AC compressorRepair

Connect the XR 25 (injection fiche 3)

Enter code D03, ISO selector on S8

Put the passenger compartment fan and the AC

on max

Does right hand bargraph 14 illuminate? (1)

yes

Check the wiring between :

- track 2 of relay 474 and track 22 on

the computer

- the shunt between track 1 and

track 5 of relay 474 (X53D)

Repair if necessary

Does the fault persist?

The injection is preventing the AC

from operating - look for a possible

cause or change the injection

computer

yesDoes left hand bargraph 14 illuminate? no See Chart 2G

Is this correct?

Check for + 12 Volts ontrack B3 of the greyconnector R34

Fan and AC on max

Is this correct?

Shunt the tri-function pressostatbetween tracks A1 and C1 and checkthat the compressor operates Doesthe compressor operate?

Repair the wiring betweentrack B3 of connection R34and the fuse box

Repair the wiringbetween track 5 of relay

474 and track C1 of thepressostat

yesChange relay 474

Press on a filling valve to see ifthere is refrigerant in the circuit

NOTE:with the engine stopped,the pressure gauges should readbetween 5 and 7 bars HP and LP for

a workshop temperature of20/25°C

Is this correct ?no

Correct

Adjust therefrigerant level.no

Fault finding - Fault charts

FAULT CHART N° 2B : No cool air - X53C ; X538 ; X53V vehicles

no See Chart 2F

Check for + 12 Volts on track 3 of relay 474

Is there + 12 Volts ?

Check the wiring between track 3

of relay 474and the AC compressorRepair

Connect the XR 25 (injection fiche 3)

Enter code D03, ISO selector on S8

Put the passenger compartment fan and the AC

on max

Does right hand bargraph 14 illuminate?

yes

Check the wiring between :

- track 2 of relay 474 and track 22 on

the computer (or track 23 for F3P;

Is this correct?

no

Check for + 12 Volts ontrack A5 of the brownconnector R34

(Fan and AC on max)

Check on track B1 of theblack connector R99 of thecomponent unit for + 12Volts (fan and AC on max)

Is there 12 Volts ?

yesChange relay 474

Press on a filling valve to see ifthere is refrigerant in the circuit

NOTE:with the engine stopped,the pressure gauges should readbetween 5 and 7 bars HP and LPfor a workshop temperature of20/25°C

Is this correct ?

no

yesno

noyes

(See next page)

62

Injection is preventing the AC from

operating - look for a possible cause or

change the injection computer

Correct

noyes

Repair the electricalwiring between track 5

of relay 474 and track C1

of the pressostat

noyes

Shunt the tri-function pressostatbetween tracks A1 and C1 and checkthat the compressor operates Doesthe compressor operate?

Fault finding - Fault charts

FAULT CHART N° 2B (cont) : No cool air - X53C ; X538 ; X53V vehicles

Adjust the refrigerant

level

Change the tri-function pressostat

Repair the wiringbetween track B1 ofcomponent unit andtrack A5 of brownconnector R34

Check for + 12 Volts on track

5 of the electronicthermostat (fan and AC onmax)

Is there 12 Volts ?

yes

Repair the wiring betweentrack 5 on the electronicthermostat and track B1 onthe black connector R99

Check for + 12 Volts on

See Chart 2D

yesno

Fault finding - Fault charts

FAULT CHART N° 2C : No cool air - X53A AC Delco injection vehicles

no See Chart 2F

Check for + 12 Volts on track 3 of relay 474

Is there + 12 Volts ? Check the wiring between track 3of relay 474and the AC compressor

Repair

Connect the XR 25 (injection fiche)

Enter code D03, ISO selector on S2

Put the passenger compartment fan and the AC

on max

Does left hand bargraph 17 illuminate?

Check the wiring between :

- track 2 of relay 474 and track 22 on the

injection computer

- track 1 of relay 474 and track 5 of the

fuel pump relay 236

Repair if necessary

The injection computer is preventingoperation of the air conditioning Look for apossible cause (strategy) or change theinjection computer

yesDoes left hand bargraph 18 illuminate? no See Chart 2G

yes

no

Check for+12Volts between

tracks 1 and 2 of relay 474

Is there + 12 Volts ?

no

Check for +12 Volts on track A1 of the tri-function pressostat connector Is this correct?

yes

Check for+12Volts ontrack B3 of the greyconnector R34

(Passenger compartmentfan and AC on max.)

Is this correct?

Shunt the tri-function pressostat between tracks A1 and C1 and check that the compressor operates Does the compressor operate?

Repair the electrical wiringbetween track 5 of relay 474and track C1 of the

pressostat

Press on a filling valve to see if

there is refrigerant in the circuit

NOTE:with the engine stopped,

the pressure gauges should read

between 5 and 7 bars HP and LP

for a workshop temperature of

Is there+12Voltson track 5 of

no

Changerelay 474

Does right hand bargraph 18 illuminate? no

yes

62

Fault finding - Fault charts

FAULT CHART N° 2D : No cool air Test conditions :

- Passenger compartment fan operating

- AC on MAX.

yes Refer to Chart 2E on the next page

Check for + 12 Volts on track 3 of the AC relay

Check the wiring between tracks :

- 5 on relay 690 and A2 on black connectorR99

- A2 on black connector R99 and + 12 Volts

at the fuse box

Check for + 12 Volts on track B3 of control panel

connector 319 (On/Off info)

Passenger compartment fan operating and AC on

NORM

Is this correct?

no

Disconnect control panel connector 319 and check

the continuity between tracks B1 and B3 and

between tracks B1 and B4

Passenger compartment fan operating and AC on

NORM

Is this correct?

Repair the earth on track A5 and + 12Volts

on trackB1of control panel 319

yes Change the relay

Repair the wiring between track 2 on relay 690and track B4 on connector R99

Track B4 on connector R99 and vehicle earthM11

Fault finding - Fault charts

FAULT CHART N° 2E : No cool air - Only for vehicles X533 ; X536 ; X537 ; Model Year 1989 or 1990.

Repair the wiring between track A2 of black

connector R99 and + 12 Volts on the fuse box

Repair the wiring between track 7 of theelectronic thermostat and track A2 ofconnector R99

Fault finding - Fault charts

FAULT CHART N° 2F : No cool air Test conditions :

- Passenger compartment fan operating

- AC on MAX.

Repair the wiring between track 30 on theinjection computer(track 13for X53AACDELCO injection) and track D5 of brownconnector R34

If the fault persists, the injection computer is

at fault, preventing the AC system fromoperating

Check for + 12 Volts on track B4 of control panel

connector319 (On/Off info)

Is this correct?

yes

With the black control panel connector

disconnected, check the continuity between

tracks : B1 and B4 - B1 and B3

Is this correct?

yes

Repair the wiring between tracks :

- A5 of the control panel and earth M10

- B1 of the control panel and the fuse box

(+after ignition)

Check the continuity between track B4 ofblack control panel connector 319 and trackD5 on brown connector R34

Repair the wiring

no

no Change the control panel

62

Fault finding - Fault charts

FAULT CHART N° 2G : No cool air Test conditions :

- Passenger compartment fan operating at maximum speed

- AC on MAX.

Repair the wiring between track B1 on thecomponent unit and track A5 on brownconnector R34

no

yes

yes

Under these test conditions, check for + 12 Volts

on track B1 of the black connector R99 for the

component unit

Is there + 12 Volts ?

Check for + 12 Volts (still under these test

conditions) on track 5 of the electronic

thermostat

Is there + 12 Volts ?

Change the evaporator sensor

Check for + 12 Volts (still under these test

conditions) on track 7 of the electronic

thermostat

Repair the wiring betweentracks :

no

All types X53F, X53C,

X53V, X538

Repair the wiring between

track A5 of the brown

connector R34 and track 34

on the injection computer

(track 14for AC Delco)

If the fault persists, the

injection computer is at

fault

Shunt the tri-functionpressostat between tracksA1 and C1 and check if thecompressor operates Doesthe compressor operate ?

no

yes

Press on a filling valve to see ifthere is refrigerant in thecircuit

NOTE:with the enginestopped,the pressure gaugesshould read between 5 and 7bars HP and LP for a workshoptemperature of 20/25°C

Before changing the electronic thermostat,check the earth on track 6 and the shuntbetween tracks 3 and 4

Connect the XR 25 (injection fiche 3)

Enter code D03, ISO selector on S2

Under these test conditions shunt the evaporator

sensor and check if the compressor operates and

left hand bargraph 14 illuminates (right hand

bargraph 18 for X53A AC DELCO injection)

Does the compressor operate ?

Under these test conditions, check for

+ 12Volts on the brown connector

62

Fault finding - Fault charts

FAULT CHART N° 2H : No cool air Test conditions :

- Passenger compartment fan operating at maximum speed.

Before changing the temperature switch,check that the engine is not overheating,check the cooling system

yes

Pressostat shunt still in place, shunt the coolant

temperature switch between tracks 1 and 3 of the

black connector

Does the compressor operate?

Repair the wiring between track C1 of thepressostat and track 1 of the coolanttemperature switch

Reconnect the coolant temperature switch

Check for + 12 Volts on track 3 of relay 584 or 474

no

Repair the wiring between track 4 of relay

584 or 474 and the compressor

yes

no Change relay 584 or 474 (it is stuck on track 5).

no Up to year of manufacture 93The PAS pressostat should be closed, check if

this is normal (strategy) or change thepressostat

After year of manufacture 93

There is a short circuit to +12volts betweentrack 1 of relay 474 and track 4 of timer 635

A (See next page)

e53531.1

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